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Coherent tunneling in ferromagnetic planar junctions: Role of thin layers at the barriers | Attenuated Oscillation of the Tunneling Magnetoresistance in a Ferromagnet-Metal-Insulator-Ferromagnet Tunneling Junction | Unsupervised joint decomposition of a spectroscopic signal sequence | eng_Latn | 27,800 |
Spin-resolved single-atom imaging of $^6$Li in free space | Deep Learning-Assisted Classification of Site-Resolved Quantum Gas Microscope Images | Reflected Backward SDEs and American Options | eng_Latn | 27,801 |
Magnetic properties of transition-metal atoms and thin layers deposited on nonmagnetic metals. | Superconducting Transition Temperature in YBa , Cu , O 8 / LaZl 3 Calls Mn 03 / YBa , Cu , O 8 Heterostructure | Transition metal-free one-pot synthesis of nitrogen-containing heterocycles | eng_Latn | 27,802 |
Spin wave eigenmodes in transversely magnetized thin film ferromagnetic wires | Spin Hall-induced auto-oscillations in ultrathin YIG grown on Pt | Transcriptional activation of HIF-1 by a ROS-ERK axis underlies the resistance to photodynamic therapy | eng_Latn | 27,803 |
Uniqueness in phaseless inverse scattering problems with superposition of incident point sources | Point Sources and Multipoles in Inverse Scattering Theory | Surface ligand influenced free radical protection of superparamagnetic iron oxide nanoparticles (SPIONs) toward H9c2 cardiac cells | eng_Latn | 27,804 |
Intercollisional dynamics of hole spin, when free holes are subjected to an external electric field, is considered. Coherent evolution of spin projections and the population in valence bands is presented for dc and harmonic fields. Spin operators in the band representation are found and it is shown that there appears an uncertainty related with band degeneracy. The results obtained may be useful in the simulation of simultaneous spin and charge transport in p-type semiconductors, for example, by the Monte Carlo method. | Ultrafast and coherent transitions induced by electric field between spin states of the valence band in semiconductors are considered. It is shown that using optimized femtosecond electric fields one can, in principle, control a selected component of the hole spin. The feasibility of hole spin switching is illustrated using the well-known Luttinger-Kohn Hamiltonian for valence bands of tetrahedral and zinc-blende semiconductors. The presented results may be useful in the development of the ultrafast semiconductor spintronics. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,805 |
Recent experimental progress in Hall measurements in bilayer graphene in the so-called open-face configuration of boron nitride encapsulated samples, together with the earlier technique of suspended samples, allows for precise observation of the fractional quantum Hall effect (FQHE) in all 4 subbands of the Lowest Landau level (with n = 0 and n = 1) and in the next LL subbands (with n = 2) in the bilayer system. Many newly observed FQHE features do not agree with a conventional model of composite fermions and reveal a different hierarchy in comparison to monolayer graphene or GaAs 2DEG. We explain the peculiarity of the FQHE hierarchy in the bilayer system in the framework of a topological approach, which includes the composite fermion model as its special case. Inclusion of a topological effect caused by the hopping of electrons between the two sheets in the bilayer system allowed for an explanation of the FQHE hierarchy in the graphene bilayer in satisfactory accordance with the experimental observations. | The electronic properties of graphene are described by a Dirac Hamiltonian with a fourfold symmetry of spin and valley. This symmetry may yield novel fractional quantum Hall (FQH) states at high magnetic field depending on the relative strength of symmetry breaking interactions. However, observing such states in transport remains challenging in graphene, as they are easily destroyed by disorder. In this work, we observe in the first two Landau levels (v<6) the composite-fermion sequences of FQH states at p/(2p+1) between each integer filling factor. In particular, odd numerator fractions appear between v=1 and v=2, suggesting a broken valley symmetry, consistent with our observation of a gap at charge neutrality and zero field. Contrary to our expectations, the evolution of gaps in a parallel magnetic field suggests that states in the first Landau level are not spin-polarized even up to very large out of plane fields. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,806 |
Errors arising from finite sample size and structure effects, sample displacement, background noise level, and other imperfections, often confronted in high-sensitivity magnetization measurements, are characterized. A semianalytical finite-element analysis code is developed in MATHCAD, MAPLE, and C to simulate the response of a second-order gradiometer pickup coil assembly (for example, the Quantum Design magnetic property measurement system MPMS® XL). The flux integrals are computed for given sample shape, orientation, and position, arbitrary direction of the magnetization, and magnetic moment spatial distribution, and their axial distributions are analyzed using all three standard regression procedures (geometrical average, linear regression, nonlinear least squares). Procedures are described for recovering the component of the magnetic moment orthogonal to the axis of the gradiometer, estimating the axial projection of the total dipole density, and reconstructing the on-axis magnetization profile by va... | Water-based suspensions of single-core iron-oxide particles withnominal sizes 15 - 50 nm were studied by AC and DC magnetometrytechniques in order to determine their suitability for use in thevolume amplified nanobead detection assay (VAM-NDA). The VAM-NDA candetect specific biomolecules, which have been magnetically tagged andvolume amplified, by measuring the difference in the Brownianrelaxation rate compared to a negative control sample. Single-corenanoparticles are expected to have a stronger low-field magneticresponse, narrower size distributions and to better be described bythe theoretical model constituting the foundation of the VAM-NDA, thanparticles consisting of a multi-grained cluster embedded in anon-magnetic coating, which previously have been used in theassay. Experiments showed that all particles exhibited signs of spindisorder, including a diminished magnetic response. The particles withnominal core diameters 25, 30 and 40 nm were superparamagneticallyblocked at room temperature and very narrowly distributed insize. Therefore they would be useful for improving the assay, in spiteof their diminished magnetic response. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,807 |
Direct Evidence for Edge-Contaminated Vortex Phase in a Nb Single Crystal using Neutron Diffraction | Magnetic Susceptibility Of Superconductors And Other Spin Systems | Why Non-Uniform Density Suppresses the Precessing Vortex Core | eng_Latn | 27,808 |
Classification of reflection symmetry protected topological semimetals and nodal superconductors | Crystalline Kitaev spin liquids | The evaluation of non-reflecting boundary conditions for duct acoustic computation | eng_Latn | 27,809 |
Adiabatic continuity between Hofstadter and Chern insulator states | Creating Floquet Chern insulators with magnetic quantum walks | Failure of Rorschach-Comprehensive-System-based testimony to be admissible under the Daubert-Joiner-Kumho standard. | eng_Latn | 27,810 |
Parametrically Stimulated Recovery of a Microwave Signal Stored in Standing Spin-Wave Modes of a Magnetic Film | Dual Band Magnonic Crystals: Model System and Basic Spin Wave Dynamics | No evidence for apparent extent between parallels as the basis of the Poggendorff effect | eng_Latn | 27,811 |
Transition between tetramer and monomer phases driven by vacancy configuration entropy on Bi/Ag(001) | Electrically driven spin torque and dynamical Dzyaloshinskii-Moriya interaction in magnetic bilayer systems | Completely Stale Transmitter Channel State Information is Still Very Useful | eng_Latn | 27,812 |
Kondo conductance across the smallest spin 1/2 radical molecule | Au(111): A theoretical study of the surface reconstruction and the surface electronic structure | Well-posedness results for the generalized Benjamin-Ono equation with arbitrary large initial data | eng_Latn | 27,813 |
The purpose of this paper is to prove unexpected connections among the asymptotic behavior of the magnetization, the structure of the phase transitions, and a class of polynomials that we call the Ginzburg-Landau polynomials. The model under study is a meanfield version of an important lattice-spin model due to Blume and Capel. It is defined by | In this paper we investigate the relationship between the mixing times of the Glauber dynamics of a statistical mechanical system with its thermodynamic equilibrium structure. For this we consider the mean-field Blume-Capel model, one of the simplest statistical mechanical models that exhibits the following intricate phase transition structure: within a two dimensional parameter space there exists a curve at which the model undergoes a second-order, continuous phase transition, a curve where the model undergoes a first-order, discontinuous phase transition, and a tricritical point which separates the two curves. We determine the interface between the regions of slow and rapid mixing. In order to completely determine the region of rapid mixing, we employ a novel extension of the path coupling method, successfully proving rapid mixing even in the absence of contraction between neighboring states. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,814 |
Toroidal carbon nanotubes (TCN's) are threaded by magnetic flux (φ). The magneto-electronic structures are studied within the tight-binding model. The curvature effect, which is due to the misorientation of the π-electron orbitals, might play an important role on the low energy electronic states. The thin TCN's, with armchair-zigzag and zigzag-armchair structures, exhibit four (three) types of energy gaps in the presence (absence) of the curvature effect. The magnetoelectronic structures clearly vary with φ except the thin zigzag-armchair TCN's. They could exhibit the periodical Aharonov-Bohm oscillations, since the Zeeman splitting is generally negligible except at large φ's. | Tessellated tori, generated here from square-like tiled lattices, are closely related to cylinders and capped tubes. This way of building them enables the orientation of their bonds, and so the geometric proportions of the torus, to be specified for molecular mechanics calculations and, along with their transformation into capped tubes this is illustrated and discussed in the light of their energetic stability. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 27,815 |
Surface structural effects accompanying the antiferromagnetic-ferromagnetic magnetostructral transition of epitaxial FeRh thin films were investigated by grazing incidence x-ray scattering. Measurement of the film lattice parameters and variation of x-ray incident angles allow observation of the transition character on scales ranging from a few nm to the total through-thickness of the film. Out-of-plane lattice measurements confirm that the ferromagnetic phase nucleates from the surface during the heating process and is retained at the surface below the transition temperature during the cooling process. These results suggest that surface strain relief fosters nucleation of the ferromagnetic phase. | Spin-wave resonance measurements were performed in the mixed magnetic phase regime of a Pd-doped FeRh epilayer that appears as the first-order ferromagnetic-antiferromagnetic phase transition takes place. It is seen that the measured value of the exchange stiffness is suppressed throughout the measurement range when compared to the expected value of the fully ferromagnetic regime, extracted via the independent means of a measurement of the Curie point, for only slight changes in the ferromagnetic volume fraction. This behavior is attributed to the influence of the antiferromagnetic phase: inspired by previous experiments that show ferromagnetism to be most persistent at the surfaces and interfaces of FeRh thin films, we modelled the antiferromagnetic phase as forming a thin layer in the middle of the epilayer through which the two ferromagnetic layers are coupled up to a certain critical thickness. The development of this exchange stiffness is then consistent with that expected from the development of an exchange coupling across the magnetic phase boundary, as a consequence of a thickness dependent phase transition taking place in the antiferromagnetic regions and is supported by complimentary computer simulations of atomistic spin-dynamics. The development of the Gilbert damping parameter extracted from the ferromagnetic resonance investigations is consistent with this picture. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,816 |
In the present work, we have prepared Mn-doped Ge using different annealing approaches after Mn ion implantation, and obtained samples with hole concentrations ranging from 1018 to 2.1×1020 cm−3, the latter being the highest reported so far. Based on the magnetotransport properties of Mn doped Ge, we argue that the hole concentration is a decisive parameter in establishing carrier-mediated ferromagnetism in magnetic Ge. | The integration of ferromagnetic Mn5Ge3 with the Ge matrix is promising for spin injection in a silicon-compatible geometry. In this paper, we report the preparation of magnetic Mn5Ge3 nanocrystals embedded inside the Ge matrix by Mn ion implantation at elevated temperature. By X-ray diffraction and transmission electron microscopy, we observe crystalline Mn5Ge3 with variable size depending on the Mn ion fluence. The electronic structure of Mn in Mn5Ge3 nanocrystals is a 3d6 configuration, which is the same as that in bulk Mn5Ge3. A large positive magnetoresistance has been observed at low temperatures. It can be explained by the conductivity inhomogeneity in the magnetic/semiconductor hybrid system. | The seeking of room temperature ferromagnetic semiconductors, which take advantages of both the charge and spin degrees of freedom of electrons to realize a variety of functionalities in devices integrated with electronic, optical, and magnetic storage properties, has been a long-term goal of scientists and engineers. Here, by using the spin-polarized density functional theory calculations, we predict a new series of high temperature ferromagnetic semiconductors based on the melilite-type oxysulfide Sr$_2$MnGe$_2$S$_6$O through hole (K) and electron (La) doping. Due to the lack of strong antiferromagnetic superexchange between Mn ions, the weak antiferromagnetic order in the parent compound Sr$_2$MnGe$_2$S$_6$O can be suppressed easily by charge doping with either $p$-type or $n$-type carriers, giving rise to the expected ferromagnetic order. At a doping concentration of 25%, both the hole-doped and electron-doped compounds can achieve a Curie temperature ($T_\text{c}$) above 300 K. The underlying mechanism is analyzed. Our study provides an effective approach for exploring new types of high temperature ferromagnetic semiconductors. | eng_Latn | 27,817 |
We propose a scheme for generating Rashba spin-orbit coupling and perpendicular Zeeman field simultaneously for cold fermionic atoms in a harmonic trap through the coupling between atoms and laser fields. The realization of Rashba spin-orbit coupling and perpendicular Zeeman field provides opportunities for exploring many topological phenomena using cold fermionic atoms. We focus on the intrinsic anomalous Hall effect and show that it may be observed through the response of atomic density to a rotation of the harmonic trap. | We show that the combination of spin-orbit coupling and in-plane Zeeman field in a two-dimensional degenerate Fermi gas can lead to a larger parameter region for Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phases than that using spin-imbalanced Fermi gases. The resulting FFLO superfluids are also more stable due to the enhanced energy difference between FFLO and conventional Bardeen-Cooper-Schrieffer (BCS) excited states. We clarify the crucial role of the symmetry of Fermi surface on the formation of finite momentum pairing. The phase diagram for FFLO superfluids is obtained in the BCS-BEC crossover region and possible experimental observations of FFLO phases are discussed. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,818 |
Employing first principles density functional calculations, together with solution of the low-energy, model Hamiltonian constructed in a first principles manner, we explored the origin of magnetism and $T_c$ trend in Cr-based double perovskite series, Sr$_2$CrB$'$O$_6$ (B$'$=W/Re/Os). Our study shows that the apparently puzzling $T_c$ trend in Sr$_2$CrB$'$O$_6$ (B$'$=W/Re/Os) series can be understood in terms of the interplay of the hybridization driven mechanism and the super-exchange mechanism. | High-temperature insulating ferrimagnetism is investigated in order to further reveal its physical mechanisms, as well as identify potentially important scientific and practical applications relative to spintronics. For example, double perovskites such as Sr2FeOsO6 and Ca2FeOsO6 are shown to have puzzling magnetic properties. The former is a low-temperature antiferromagnet while the latter is a high-temperature insulating ferrimagnet. In order to understand the underlying mechanisms, we have investigated the frustrated magnetism of A2FeOsO6 by employing density functional theory and maximally-localized Wannier functions. We find lattice distortion enhances the antiferromagnetic nearest-neighboring Fe-O-Os interaction, however weakens the antiferromagnetic interactions via the Os-O-O-Os and Fe-O-Os-O-Fe paths, so is therefore responsible for the magnetic transition from the low-temperature antiferromagnetism to the high-temperature ferrimagnetism as the decrease of the A(2+) ion radii. Also discussed is the 5d(3)-3d(5) superexchange. We propose that such superexchange is intrinsically antiferromagnetic instead of ferromagnetic as previously thought. Our work clearly illustrates the magnetic frustration can be effectively relieved by lattice distortion, thus paving the way for tuning of complex magnetism in yet other 3d-5d (4d) double perovskites. | Prognostics and health management (PHM) seeks to identify and isolate reliability problems in products (diagnostics) and predict a product's remaining useful life (prognostics). In this paper, a four-step PHM approach for power supplies is presented: 1) precursor parameter identification based on historical data analysis and failure mechanism analysis; 2) baseline establishment by conducting experiments under different environmental and usage conditions and characterizing precursor parameters for healthy power supplies; 3) baseline verification by conducting similar experiments for fielded power supplies; and 4) testing. Precursor parameter identification for one switch-mode power supply (SMPS) was carried out. The power metal-oxide semiconductor field-effect transistor, insulated-gate bipolar transistor, and the Schottky diode were identified as the majority cause by historical data analysis. Gate oxide leakage current, threshold voltage, transconductance, junction temperature, VCE (on), and contact resistance were determined to be monitored parameters for this SMPS after a failure mechanism analysis. | eng_Latn | 27,819 |
(151)Eu Mössbauer spectroscopy and neutron powder diffraction are combined to show that the tetragonal (I4mm #107) compound EuNiGe3 orders magnetically below [Formula: see text] K and adopts a complex incommensurate helicoidal magnetic structure at 3.6 K, with a propagation vector [Formula: see text] and a Eu moment of 7.1(2) [Formula: see text]. On warming through 6 K an incommensurate sinusoidal modulation develops and dominates the magnetic order by 12 K. | In this article, we focus on (1) type-II multiferroics driven by spiral spin orderings and (2) magnetoelectric couplings in multiferroic skyrmion-hosting materials. We present both phenomenological understanding and microscopic mechanisms for spiral spin state, which is one of the essential starting points for type-II multiferroics and magnetic skyrmions. Two distinct mechanisms of spiral spin states (frustration and Dzyaloshinskii–Moriya [DM] interaction) are discussed in the context of the lattice symmetry. We also discuss the spin-induced ferroelectricity on the basis of the symmetry and microscopic atomic configurations. We compare two well-known microscopic models: the generalized inverse DM mechanism and the metal-ligand d-p hybridization mechanism. As a test for these models, we summarize the multiferroic properties of a family of triangular-lattice antiferromagnets. We also give a brief review of the magnetic skyrmions. Three types of known skyrmion-hosting materials with multiferroicity are discussed from the view point of crystal structure, magnetism, and origins of the magnetoelectric couplings. For exploration of new skyrmion-hosting materials, we also discuss the theoretical models for stabilizing skyrmions by magnetic frustration in centrosymmetric system. Several basic ideas for material design are given, which are successfully demonstrated by the recent experimental evidences for the skyrmion formation in centrosymmetric frustrated magnets. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 27,820 |
Starting from a model Hamiltonian for the normal state of the topological insulator Bi2Se3, we construct a pseudospin basis for the single-particle wavefunctions. Considering weak superconducting pairing near the Fermi surface, we express the recently proposed superconducting order parameters for Cu doped Bi2Se3 in this basis. For the odd parity states, the d-vectors specifying the order parameter can have unusual momentum dependence for certain parameter regimes. Some peculiar results in the literature for surface states are discussed in light of the forms of these d(k)'s. Properties of the even parity states are also illuminated using this pseudospin basis. Results from this single-band description are compared with those from the full two-band model. | Sr2RuO4 is the best candidate for spin-triplet superconductivity, an unusual and elusive superconducting state of fundamental importance. In the last three decades, Sr2RuO4 has been very carefully studied and despite its apparent simplicity when compared with strongly correlated high-T ::: c cuprates, for which the pairing symmetry is understood, there is no scenario that can explain all the major experimental observations, a conundrum that has generated tremendous interest. Here, we present a density-functional-based analysis of magnetic interactions in Sr2RuO4 and discuss the role of magnetic anisotropy in its unconventional superconductivity. Our goal is twofold. First, we access the possibility of the superconducting order parameter rotation in an external magnetic field of 200 Oe, and conclude that the spin–orbit interaction in this material is several orders of magnitude too strong to be consistent with this hypothesis. Thus, the observed invariance of the Knight shift across T ::: c has no plausible explanation, and casts doubt on using the Knight shift as an ultimate litmus paper for the pairing symmetry. Second, we propose a quantitative double-exchange-like model for combining itinerant fermions with an anisotropic Heisenberg magnetic Hamiltonian. This model is complementary to the Hubbard-model-based calculations published so far, and forms an alternative framework for exploring superconducting symmetry in Sr2RuO4. As an example, we use this model to analyze the degeneracy between various p-triplet states in the simplest mean-field approximation, and show that it splits into a single and two doublets with the ground state defined by the competition between the “Ising” and “compass” anisotropic terms. A new framework for analysing the role of magnetic interactions on the unconventional superconductivity in strontium ruthenate. Strontium ruthenate is an unconventional superconductor that used to be touted a potential three-dimensional analogue of Helium-3, as it was thought to have the same type of chiral p-wave pairing. It is now widely accepted that this is not the case, but many questions remain over the exact nature of the pairing, particularly regarding the role of magnetic interactions. An international team of researchers led by Bongjae Kim and Sergii Khmelevskyi from the University of Vienna and Vienna University of Technology now present a framework that can incorporate the leading isotropic and anisotropic magnetic interactions in a different but complimentary way to the widely used Hubbard-model, providing an alternative way of exploring the superconducting pairing symmetry. | Prognostics and health management (PHM) seeks to identify and isolate reliability problems in products (diagnostics) and predict a product's remaining useful life (prognostics). In this paper, a four-step PHM approach for power supplies is presented: 1) precursor parameter identification based on historical data analysis and failure mechanism analysis; 2) baseline establishment by conducting experiments under different environmental and usage conditions and characterizing precursor parameters for healthy power supplies; 3) baseline verification by conducting similar experiments for fielded power supplies; and 4) testing. Precursor parameter identification for one switch-mode power supply (SMPS) was carried out. The power metal-oxide semiconductor field-effect transistor, insulated-gate bipolar transistor, and the Schottky diode were identified as the majority cause by historical data analysis. Gate oxide leakage current, threshold voltage, transconductance, junction temperature, VCE (on), and contact resistance were determined to be monitored parameters for this SMPS after a failure mechanism analysis. | eng_Latn | 27,821 |
The authors consider an Ising system in two dimensions with anisotropic ferromagnetic interactions in the strong anisotropic limit and study, via numerical simulation, the dynamics of the interface separating two domains. Since the system is highly anisotropic (Jx>>Jy with Jx>>kBT) and they neglect the overhang configurations, the model in some aspects is an SOS (solid on solid) model. In this case the domain wall moves in one direction (x) and they are in the so-called 'strip geometry' (L* infinity ), L being the size of the system in the y direction. The dynamics of this interface can be reduced, as has been already shown, to the correlated motion of random walkers. Their previous study at high temperature (Jy<kBT) has shown that for the equilibrium case where the mean position of the centre of mass (CM) does not change, the exponents z and alpha of the scaling relation describing the dynamics of the width of the wall have values 2 and 0.5, respectively. An equality z-2 alpha =1 was also obtained from cross-over arguments. In this paper they extend their study, by including a uniform external magnetic field, to the nonequilibrium case where CM mean position of the interface moves with time. They consider both the high- and low-temperature cases (Jy/kBT=0.1 and 1), and obtain the equality z-2 alpha =- alpha CM; alpha CM being exponent characterizing the size dependence of the diffusion coefficient of the CM, i.e. D approximately Lalpha CM in the long-time regime. For equilibrium they get alpha CMapproximately -1. For the low-temperature, field-driven case they find the exponent approaching the value -0.5 as the magnetic field increases from 0 to H/Jy=2. Since the static exponent alpha obtained is always near 0.5, their results in the low-temperature case correspond to z=2 for equilibrium and approach the value z=3/2 predicted by Kardar, Parisi and Zhang in the non-equilibrium situation. The values of the exponent z obtained in different cases (equilibrium and non-equilibrium) by calculating the CM exponent alpha CM are the same as those obtained from known equalities: z+ alpha =2 (non-equilibrium) and z-2 alpha =d-1 (equilibrium). Therefore they propose that the single equality z-2 alpha =- alpha CM may apply far more generally and the study of CM dynamics may therefore provide an alternative (or complementary) way of analysing the results of domain growth simulations. They also note that their results are in agreement with two-dimensional results on the restricted solid on solid model (RSOS). | We investigate the interface dynamics of the two-dimensional stochastic Ising model in an external field under helicoidal boundary conditions. At sufficiently low temperatures and fields, the dynamics of the interface is described by an exactly solvable high-spin asymmetric quantum Hamiltonian that is the infinitesimal generator of the zero range process. Generally, the critical dynamics of the interface fluctuations is in the Kardar-Parisi-Zhang universality class of critical behavior. We remark that a whole family of RSOS interface models similar to the Ising interface model investigated here can be described by exactly solvable restricted high-spin quantum XXZ-type Hamiltonians. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,822 |
BACKGROUND ::: Nuclear factor (NF)-κB plays an essential role in inflammation. We tested this role by administering NF-κB-inhibitors into rats undergoing a well-established model of colonic anastomotic healing. ::: ::: ::: METHODS ::: Wistar rats underwent laparotomy, descending colonic transection, and handsewn reanastomosis. The animals were randomized to receive either a selective NF-κB inhibitor (parthenolide 0.5 mg/kg or resveratrol 0.5 mg/kg) or an equal volume of water by gavages before operation and then daily after surgery. Animals were sacrificed either immediately after anastomotic construction (d 0) or at the third, fifth, or seventh postoperative day. ::: ::: ::: RESULTS ::: Both parthenolide and resveratrol treatment led to early significant increases in plasma levels of IL-6. On d 7, hydroxyproline levels were significantly higher in the parthenolide and resveratrol groups. A similar pattern was observed with the bursting pressure. In contrast, gelatinase activity (MMP-2 and MMP-9 expression) was significantly higher in the control group on postoperative d 3. On d 3, expression of NF-κB activity was up-regulated in the anastomotic area. Both parthenolide and resveratrol completely attenuated NF-κB activity. Study groups also developed more marked inflammatory cell infiltration and collagen deposition on histology analysis. ::: ::: ::: CONCLUSIONS ::: Parthenolide and resveratrol significantly improved healing and mechanical stability of colonic anastomoses in rats during the early postoperative period. Both agents may be acting to accelerate the host reparative process as well as to enhance protection of the anastomotic wound bed. | Disturbances of extracellular matrix homeostasis are associated with a number of pathological conditions. The ability of extracellular matrix to provide contextual information and hence control the individual or collective cellular behavior is increasingly being recognized. Hence, newer therapeutic approaches targeting extracellular matrix remodeling are widely investigated. We reviewed the current literature showing the effects of resveratrol on various aspects of extracellular matrix remodeling. This review presents a summary of the effects of resveratrol on extracellular matrix deposition and breakdown. Mechanisms of action of resveratrol in extracellular matrix deposition involving growth factors and their signaling pathways are discussed. Involvement of phosphoinositol-3-kinase/Akt and mitogen-activated protein kinase pathways and role of transcription factors and sirtuins on the effects of resveratrol on extracellular matrix homeostasis are summarized. It is evident from the literature presented in this review that resveratrol has significant effects on both the synthesis and breakdown of extracellular matrix. The major molecular targets of the action of resveratrol are growth factors and their signaling pathways, phosphoinositol-3-kinase/Akt and mitogen-activated protein kinase pathways, transcription factors, and SIRT-1. The effects of resveratrol on extracellular matrix and the molecular targets appear to be related to experimental models, experimental environment as well as the doses. | Sr2RuO4 is the best candidate for spin-triplet superconductivity, an unusual and elusive superconducting state of fundamental importance. In the last three decades, Sr2RuO4 has been very carefully studied and despite its apparent simplicity when compared with strongly correlated high-T ::: c cuprates, for which the pairing symmetry is understood, there is no scenario that can explain all the major experimental observations, a conundrum that has generated tremendous interest. Here, we present a density-functional-based analysis of magnetic interactions in Sr2RuO4 and discuss the role of magnetic anisotropy in its unconventional superconductivity. Our goal is twofold. First, we access the possibility of the superconducting order parameter rotation in an external magnetic field of 200 Oe, and conclude that the spin–orbit interaction in this material is several orders of magnitude too strong to be consistent with this hypothesis. Thus, the observed invariance of the Knight shift across T ::: c has no plausible explanation, and casts doubt on using the Knight shift as an ultimate litmus paper for the pairing symmetry. Second, we propose a quantitative double-exchange-like model for combining itinerant fermions with an anisotropic Heisenberg magnetic Hamiltonian. This model is complementary to the Hubbard-model-based calculations published so far, and forms an alternative framework for exploring superconducting symmetry in Sr2RuO4. As an example, we use this model to analyze the degeneracy between various p-triplet states in the simplest mean-field approximation, and show that it splits into a single and two doublets with the ground state defined by the competition between the “Ising” and “compass” anisotropic terms. A new framework for analysing the role of magnetic interactions on the unconventional superconductivity in strontium ruthenate. Strontium ruthenate is an unconventional superconductor that used to be touted a potential three-dimensional analogue of Helium-3, as it was thought to have the same type of chiral p-wave pairing. It is now widely accepted that this is not the case, but many questions remain over the exact nature of the pairing, particularly regarding the role of magnetic interactions. An international team of researchers led by Bongjae Kim and Sergii Khmelevskyi from the University of Vienna and Vienna University of Technology now present a framework that can incorporate the leading isotropic and anisotropic magnetic interactions in a different but complimentary way to the widely used Hubbard-model, providing an alternative way of exploring the superconducting pairing symmetry. | eng_Latn | 27,823 |
Based on Neel's two-sublattice collinear model, the relationship between Curie temperature Tc and temperature characteristics of Brillouin function for NiCuZn ferrites has been studied by nonlinear fitting calculation method. According to the tetrahedral A sites and the octahedral B sites of spinel structure model which do not only contain Fe3+ but also some other multiple magnetic ions (Ni2+and Cu2+), molecular-field coefficients ωaa, ωbb, and ωab = ωba have been calculated; furthermore, the ferrimagnetism and paramagnetism Curie temperature Tc calculation formula has been modified, respectively. The magnetic moment versus temperature T (below the Curie temperature Tc) and the reciprocal of paramagnetism magnetic susceptibility 1/χm versus temperature T (beyond the Curie temperature Tc) have been investigated, respectively. The values of the calculated ferrimagnetism Curie temperature are very close to the values of the testing Curie temperature, and with the same zinc content t, the values of paramagnet... | Ni-substituted manganese–zinc (MnZn) ferrites with the composition of Mn0.506– x Zn0.244Ni x Fe2.250O4.0 ( $x = 0.066{\sim}0.122$ ) have been prepared by the solid-state reaction method. The cation distribution has been investigated by the Rietveld refinement of X-ray diffraction patterns, the microstructure has been observed using a scanning electron microscope, and the magnetic property has been measured using superconductor quantum interference devices and $B$ – $H$ analyzer. The results show that Zn2+ and Ni2+ ions prefer to occupy the tetrahedron site (A sublattice) and octahedron site (B sublattice), respectively. However, Mn2+ and Fe3+ ions can enter into A and B sublattices, where the ratio of Mn2+ ions occupying A and B sublattices is 4:1. The lattice parameter ( $a$ ) of the samples decreases with the increase of Ni-substituted content. Meanwhile, based on the Neel model of collinear-spin ferrimagnetism, the molecular-field coefficients $\omega _{\rm AA}$ , $\omega _{\rm BB}$ , and $\omega _{\rm AB}$ of the Ni-substituted MnZn ferrites have been calculated, and the magnetic moment of A and B sublattices versus temperature $T$ has also been investigated. The fitting results match well with the experimental data. Both $\omega _{\rm AB}$ and $\omega _{\rm BB}$ increase with the increase of the Ni-substituted content, but $\omega _{\rm AA}$ shows the opposite variation trend. The Curie temperature also increases with the increasing of the Ni-substituted content, which is attributed to the enhancement of superexchange interaction for A–B sublattice. In addition, the temperature dependence of initial permeability and core loss has been discussed. | The low-temperature variations of the thermal expansion coefficient α(T) of a non-superconducting PrBa2Cu3O6+x ceramic in two states of oxygenation, x = 0.44 and 0.95 are reanalyzed using the α(T)/T and a(T)/T2 versus T representations. Below the Neel temperature TN of the Pr antiferromagnetic ordering which increases respectively from 9 to 14 K, two anomalies are observed. The first one is located at T2 ∼ 6–7 and 9–10 K respectively, whereas the second one occurs independently of x near Tcr(x) ∼ 4–5 K. The results are discussed and compared with earlier experimental and theoretical studies. | eng_Latn | 27,824 |
Electron spin dephasing is studied by time-resolved Kerr rotation in n-type modulation-doped CdMnTe quantum wells with very dilute Mn content. We find good agreement between measured and calculated electron spin relaxation times, considering relaxation induced by fluctuating exchange field created by the Mn spins, and taking into account inhomogeneous heating of the Mn spins by laser pulses. | We report on an example of confined magnetic ions with long spin coherence near room temperature. This was achieved by confining single Mn2+ spins in colloidal semiconductor quantum dots (QDs) and by dispersing the QDs in a proton-spin free matrix. The controlled suppression of Mn–Mn interactions and minimization of Mn–nuclear spin dipolar interactions result in unprecedentedly long phase memory (TM ~ 8 μs) and spin–lattice relaxation (T1 ~ 10 ms) time constants for Mn2+ ions at T = 4.5 K, and in electron spin coherence observable near room temperature (TM ~ 1 μs). | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,825 |
Zn substituted cobalt ferrite spinels with the general formula Zn(x)Co(1-x)Fe(2)O(4) (with x varying from 0 to 0.5) were synthesized by a co-precipitation method and calcined at 500 °C and 800 °C. It was found that Zn substitution has a big effect in decreasing the Curie temperature (T(c)), from around 440 °C for the undoped sample to ~180 °C with x = 0.5. However, these values were also strongly affected by the pre-calcination temperature of the samples, thus T(C) shifts from ~275 °C for the x = 0.3 sample to ~296 °C after calcination at 500 °C and 800 °C respectively. These effects are due to facilitation of demagnetisation by substitution of the non-magnetic Zn ions and by production of very small nanoparticles. The latter are removed by higher temperature calcinations and so T(C) increases. | This paper reports the influence of dysprosium ion (Dy3+) substitution on the structural and magnetic properties of NiDyxFe2−xO4 (0.0 ≤ x ≤ 0.1) nanoparticles (NPs) prepared using a hydrothermal method. The structure and morphology of the as-synthesized NPs were characterized via X-ray diffraction (XRD), scanning and transmission electron microscope (SEM, and TEM) analyses. 57Fe Mossbauer spectra were recorded to determine the Dy3+ content dependent variation in the line width, isomer shift, quadrupole splitting, and hyperfine magnetic fields. Furthermore, the magnetic properties of the prepared NPs were also investigated by zero-field cooled (ZFC) and field cooled (FC) magnetizations and AC susceptibility measurements. The MZFC (T) results showed a blocking temperature (TB). Below TB, the products behave as ferromagnetic (FM) and act superparamagnetic (SPM) above TB. The MFC (T) curves indicated the existence of super-spin glass (SSG) behavior below Ts (spin-glass freezing temperature). The AC susceptibility measurements confirmed the existence of the two transition temperatures (i.e., TB and Ts). Numerous models, e.g., Neel–Arrhenius (N–A), Vogel–Fulcher (V–F), and critical slowing down (CSD), were used to investigate the dynamics of the systems. It was found that the Dy substitution enhanced the magnetic interactions. | The oxygen and carbon dioxide transporting properties of the haemolymph from an amphibious Australian crab,Holthuisana transversa were investigated. Within the temperature range 15 to 35°C increasing temperature markedly decreased oxygen affinity (ΔH=−54 kJ·mol−1). The Bohr effect was small at all temperatures with a mean value of −0.13. Over the temperature range 15–35°C there was a significant increase in the cooperativity of oxygen binding. Changing the concentration of Ca,l-lactate or haemocyanin in the haemolymph could elicit no significant change in either O2 affinity or cooperativity of O2 binding. There was no evidence in support of a specific effect of CO2 on oxygen affinity of either non-dialysed or dialysed haemolymph. | eng_Latn | 27,826 |
Consideration of a compact of aligned or randomly orientated particles as an assembly of free poles, suggested that the relationship between the remanence coercivity and the packing density p is: H r (p)=H r (0)[1-C(M s /H r (0)) 2 p 4/3 ] , where H r (0) refers to isolated particles, and C is a constant. This expression was found to give very good fits to published data, both for aligned or randomly orientated particles of either ‘tape’ oxides, or ESD permanent magnet materials. The derivation of this equation involved making a number of simplifying assumptions, some of which were avoided by using computer simulations to obtain H r ( p ). Without invoking any arbitrary parameters, these yielded curves which agreed with published data for γ-Fe 2 O 3 and (for p | Some features of perpendicular recording were investigated by means of stand-still recording experiments. For this purpose several radio frequency (RF)-sputtered Co-Cr layers of two different compositions were used as media while a Permalloy single pole (SP) head was used as a write transducer. A magnetoresistive transducer (MRT) was utilized to read the recorded pattern. Further, an analytical model was developed enabling the magnetization induced by the head field in the recording medium to be calculated. Both calculations and experimental results show a sharpening of the transition, due to the demagnetizing field. For a good approximation it is sufficient to consider only the vertical head field component and vertical magnetization in the recording medium. This is a consequence of the well-developed perpendicular anisotropy and negligible in-plane remanence of the Co-Cr layers. In addition the read-out signal is completely determined by the magnetic surface charges. The remanent magnetization in the recording medium and therefore the read-out amplitude is limited by demagnetization and consequently determined by the coercivity of the Co-Cr layer. The medium noise of a dc-erased medium indicates magnetic structures of much larger dimensions than the size of the individual crystallites. This noise appears to be dependent on the saturation magnetization of the Co-Cr medium. Activation of the single pole head by a homogeneous field results in a nonlinear behavior, caused by head saturation effects. This is supported by simple one-dimensional calculations of the head field. | Oxygen (O2) is the most abundant element in the Earth’s crust. The oxygen reduction reaction (ORR) is also the most important reaction in life processes such as biological respiration, and in energy converting systems such as fuel cells. ORR in aqueous solutions occurs mainly by two pathways: the direct 4-electron reduction pathway from O2 to H2O, and the 2-electron reduction pathway from O2 to hydrogen peroxide (H2O2). In non-aqueous aprotic solvents and/or in alkaline solutions, the 1-electron reduction pathway from O2 to superoxide (O2 -) can also occur. | eng_Latn | 27,827 |
An array of spin-torque oscillators (STOs) for practical applications such as pattern recognition was recently proposed, where several STOs are connected by a common nonmagnet. In this structure, in addition to the electric and/or magnetic interactions proposed in previous works, the STOs are spontaneously coupled to each other through the nonmagnetic connector, due to the injection of spin current. Solving the Landau-Lifshitz-Gilbert equation numerically for such system consisting of three STOs driven by the spin Hall effect, it is found that both in-phase and antiphase synchronization of the STOs can be achieved by adjusting the current density and appropriate distance between the oscillators. | Spin Hall magnetoresistance (SMR) is studied in metallic bilayers that consist of heavy metal (HM) layer and a ferromagnetic metal (FM) layer. We find nearly a ten-fold increase of SMR in W/CoFeB compared to previously studied HM/ferromagnetic insulator (FI) systems. The SMR increases with decreasing temperature despite the negligible change in the W layer resistivity with temperature. A model is developed to account for the absorption of the longitudinal spin current to the FM layer, one of the key characteristics of a metallic ferromagnet. We find that the model not only quantitatively describes the HM layer thickness dependence of SMR, allowing accurate estimation of the spin Hall angle and the spin diffusion length of the HM layer, but also can account for the temperature dependence of SMR by assuming a temperature dependent spin polarization of the FM layer. These results illustrate the unique role a metallic ferromagnetic layer plays in defining spin transmission across the HM/FM interface. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,828 |
Increased bone turnover with excessive bone resorption and decreased bone formation is known to impair implant fixation. Strontium ranelate is well known as an effective antiosteoporotic agent by its dual effect of antiresorbing and bone-forming activity. This study was designed to evaluate the effect of systemic strontium ranelate (SR) treatment on fixation of hydroxyapatite (HA)-coated titanium screws in ovariectomized (OVX) rats. Twelve weeks after being OVX (n = 30) or sham (n = 10) operated, 40 female Sprague–Dawley rats received unilateral implants in the proximal tibiae. The OVX rats were randomly divided into the following groups: OVX, OVX + SRL (“L” refers to low SR dose of 500 mg/kg/day), OVX + SRH (“H” refers to high SR dose of 1000 mg/kg/day).Twelve weeks after treatment, bone blocks with implants were evaluated with micro-CT and biomechanical push-out tests. Compared to OVX animals, SR treatment increased the bone volume ratio by 51.5% and 1.1-fold, the percentage osteointegration by 1.0-fold and 1.9-fold in micro-CT evaluation, and the maximal force by 1.9-fold and 3.3-fold in biomechanical push-out test, for the low and high dose of SR, respectively. Significant correlation between micro-CT and biomechanical properties demonstrated that trabecular parameters played an important role in predicting the biomechanical properties of implant fixation. Our findings suggest that SR treatment can dose-dependently improve HA-coated screw fixation in OVX rats and facilitate the stability of the implant in the osteoporotic bone. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:578–582, 2010 | UNLABELLED ::: Recently, the use of the pharmacological agent strontium ranelate has come to prominence for the treatment of osteoporosis. While much investigation is focused on preventing disease progression, here we fabricate strontium-containing scaffolds and show that they enhance bone defect healing in the femurs of rats induced by ovariectomy. ::: ::: ::: INTRODUCTION ::: Recently, the use of the pharmacological agent strontium ranelate has come to prominence for the treatment of osteoporosis due to its ability to prevent bone loss in osteoporotic patients. Although much emphasis has been placed on using pharmacological agents for the prevention of disease, much less attention has been placed on the construction of biomaterials following osteoporotic-related fracture. The aim of the present study was to incorporate bioactive strontium (Sr) trace element into mesoporous bioactive glass (MBG) scaffolds and to investigate their in vivo efficacy for bone defect healing in the femurs of rats induced by ovariectomy. ::: ::: ::: METHODS ::: In total, 30 animals were divided into five groups as follows: (1) empty defect (control), (2) empty defects with estrogen replacement therapy, (3) defects filled with MBG scaffolds alone, (4) defects filled with MBG + estrogen replacement therapy, and (5) defects filled with strontium-incorporated mesopore-bioglass (Sr-MBG) scaffolds. ::: ::: ::: RESULTS ::: The two groups demonstrating the highest levels of new bone formation were the defects treated with MBG + estrogen replacement therapy and the defects receiving Sr-MBG scaffolds as assessed by μ-CT and histological analysis. Furthermore, Sr scaffolds had a reduced number of tartrate-resistant acid phosphatase-positive cells when compared to other modalities. ::: ::: ::: CONCLUSION ::: The results from the present study demonstrate that the local release of Sr from bone scaffolds may improve fracture repair. Future large animal models are necessary to investigate the future relationship of Sr incorporation into biomaterials. | Sr2RuO4 is the best candidate for spin-triplet superconductivity, an unusual and elusive superconducting state of fundamental importance. In the last three decades, Sr2RuO4 has been very carefully studied and despite its apparent simplicity when compared with strongly correlated high-T ::: c cuprates, for which the pairing symmetry is understood, there is no scenario that can explain all the major experimental observations, a conundrum that has generated tremendous interest. Here, we present a density-functional-based analysis of magnetic interactions in Sr2RuO4 and discuss the role of magnetic anisotropy in its unconventional superconductivity. Our goal is twofold. First, we access the possibility of the superconducting order parameter rotation in an external magnetic field of 200 Oe, and conclude that the spin–orbit interaction in this material is several orders of magnitude too strong to be consistent with this hypothesis. Thus, the observed invariance of the Knight shift across T ::: c has no plausible explanation, and casts doubt on using the Knight shift as an ultimate litmus paper for the pairing symmetry. Second, we propose a quantitative double-exchange-like model for combining itinerant fermions with an anisotropic Heisenberg magnetic Hamiltonian. This model is complementary to the Hubbard-model-based calculations published so far, and forms an alternative framework for exploring superconducting symmetry in Sr2RuO4. As an example, we use this model to analyze the degeneracy between various p-triplet states in the simplest mean-field approximation, and show that it splits into a single and two doublets with the ground state defined by the competition between the “Ising” and “compass” anisotropic terms. A new framework for analysing the role of magnetic interactions on the unconventional superconductivity in strontium ruthenate. Strontium ruthenate is an unconventional superconductor that used to be touted a potential three-dimensional analogue of Helium-3, as it was thought to have the same type of chiral p-wave pairing. It is now widely accepted that this is not the case, but many questions remain over the exact nature of the pairing, particularly regarding the role of magnetic interactions. An international team of researchers led by Bongjae Kim and Sergii Khmelevskyi from the University of Vienna and Vienna University of Technology now present a framework that can incorporate the leading isotropic and anisotropic magnetic interactions in a different but complimentary way to the widely used Hubbard-model, providing an alternative way of exploring the superconducting pairing symmetry. | eng_Latn | 27,829 |
An exhaustive study of the structural and magnetic properties of Fe7−n Pt n with n = 0, 1, 2, …7, bimetallic clusters is presented. Based on ab initio density functional theory that includes spin-orbit coupling (SOC) and graph theory, the ground state geometry, the local chemical order, and the orbital and spin magnetic moments are calculated. We show how the systems evolves from the 3-d Fe to the quasi-planar Pt clusters. These calculations show that SOC are necessary to describe correctly the composition dependence of the binding energy of these nanoalloys. We observe that the ground state geometries on the Fe rich side resemble the fcc structure adopted by bulk samples. Furthermore, we observe how the spin and orbital magnetic moments depend on the chemical concentration and chemical order. Based on these results, we estimated the magnetic anisotropy energy and found that the largest values correspond to some of the most symmetric structures, Fe5Pt2 and FePt6. To determine the degree of non-collinearity, we define an index that shows that in FePt6 the total magnetic moments, on each atom, are the less collinear. | We present size dependent spin and orbital magnetic moments of cobalt (Con (+), 8 ≤ n ≤ 22), iron (Fen (+), 7 ≤ n ≤ 17), and nickel cluster (Nin (+), 7 ≤ n ≤ 17) cations as obtained by X-ray magnetic circular dichroism (XMCD) spectroscopy of isolated clusters in the gas phase. The spin and orbital magnetic moments range between the corresponding atomic and bulk values in all three cases. We compare our findings to previous XMCD data, Stern-Gerlach data, and computational results. We discuss the application of scaling laws to the size dependent evolution of the spin and orbital magnetic moments per atom in the clusters. We find a spin scaling law "per cluster diameter," ∼n(-1/3), that interpolates between known atomic and bulk values. In remarkable contrast, the orbital moments do likewise only if the atomic asymptote is exempt. A concept of "primary" and "secondary" (induced) orbital moments is invoked for interpretation. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,830 |
It has been suggested that materials which break spatial inversion symmetry, but not time reversal symmetry, will be optically gyrotropic and display a nonlocal Hall effect. The associated optical rotary power and the suggested possibility of inducing a Kerr effect in such materials, in turn, are central to recent discussions about the nature of the pseudogap phases of various cuprate high-temperature superconductors. In this Rapid Communication, we show that optical gyrotropy and the nonlocal Hall effect provide a sensitive probe of broken inversion symmetry in 1T-TiSe2. This material was recently found to possess a chiral charge-ordered phase at low temperatures, in which inversion symmetry is spontaneously broken, while time reversal symmetry remains unbroken throughout its phase diagram. We estimate the magnitude of the resulting gyrotropic constant and optical rotary power (the Faraday effect at zero applied field) and suggest that 1T-TiSe2 may be employed as a model material in the interpretation of measurements on cuprate superconductors. DOI: 10.1103/PhysRevB.92.041111 | Coupling between charge and spin, and magnetoelectric effects more generally, have been an area of great interest for several years, with the sought-after ability to control magnetic degrees of freedom via charge currents serving as an impetus. The orbital Edelstein effect (OEE) is a kinetic magnetoelectric effect consisting of a bulk orbital magnetization induced by a charge current. It is the orbital analogue of the spin Edelstein effect in spin-orbit coupled materials, in which a charge current drives nonzero electron spin magnetization. The OEE has recently been investigated in the context of Weyl semimetals and Weyl metals. Motivated by these developments, we study a model of electrons without spin-orbit coupling which exhibits line nodes that get gapped out by via symmetry breaking due to an interaction-induced charge density wave order. This model is shown to exhibit a temperature dependent OEE, which appears due to symmetry reduction into a gyrotropic crystal class. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,831 |
A theoretical analysis of the upper critical field of d-wave superconductors with hexagonal or tetragonal crystal symmetry is carried out. This generalises the earlier work of Volovik (1988) and shows that a magnetic field can induce many different kinds of transitions between distinct d-wave superconducting phases. This occurs by changing the field strength at fixed temperature. Ultrasound absorption measurements in UPt3 are analysed using this physical picture, and the high- and low-field superconducting phases are determined. Specific heat measurements on YBa2Cu3O7 may indicate that this is a d-wave superconductor as well. It has a slight orthorhombic distortion which can split the superconducting transition into two, which also occurs in UPt3. The structure of the vortex lattice and the associated form factor for neutron scattering from this lattice changes during the transition, and criteria for distinguishing the various possibilities by this scattering are given. | Recent experiments have shown rotation of the plane of polarization of light reflected from the surface of some superconductors. The photon energy exceeds the electronic bandwidth, so that completely filled or completely empty bands must play a role. We show that in strong-coupling theory a Coulomb interaction can produce an order parameter in the unoccupied band that explains the observations. Thus the phenomenology puts tight constraints on the form of the order parameter in different bands. We propose that the experiments have detected, for the first time, the existence of a superconducting order parameter in a band far from the Fermi energy. This is only possible because of the sensitivity to delicate symmetries: a positive Kerr effect indicates that time reversal and certain mirror symmetries are broken in the ordered phase. Furthermore, detailed analysis of the results implies that in UPt3 there exist bands that have different order parameter chiralities, opening up complex new possibilities for topological superconductivity. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,832 |
Magnetic and ferroelectric properties in nanoscale are interesting topic to deal with. The primary interest is to understand the effect of simple, fast and cost effective sol gel method on the magnetic and electrical properties of Ba0.995Fe0.005Ti0.995Mn0.005O3 compounds. The study unravels the strategy for realizing multiferrocity of this composition by changing the processing temperature. Structural study confirms the infusion of Fe, Mn into the BaTiO3 lattice and its subsequent effects on the pseudo cubic and tetragonal phases. Morphological results manifest the formation of nanoparticles and evolution of grain growth upon increasing the processing temperature. Incorporation of Fe, Mn and its substantial effects on the various polymorphs of BaTiO3 is clearly portrayed by dielectric results. Room temperature ferroelectric measurements reveal the electric polarization in them. Magnetic measurements show an unusual high coercivity of 4000 Oe and its transformation to a completely paramagnetic behaviour with the subsequent changes in their phase. Thus, the pseudo cubic phase aids to retain the ferroelectric polarization with simultaneous presence of magnetic signature hints their possibility towards fruitful multi-functionality. | 1. Introduction 2. Isolated magnetic moments 3. Environments 4. Interactions 5. Order and magnetic structures 6. Order and broken symmetry 7. Magnetism in metals 8. Competing interactions and low dimensionality Appendix A: Units in electromagnetism Appendix B: Electromagnetism Appendix C: Quantum and atomic physics Appendix D: Energy in magnetism and demagnetism Appendix E: Statistical mechanics Appendix F: List of symbols Index | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,833 |
We explicitly show that the Rokhsar-Kivelson dimer model on the triangular lattice is a liquid with topological order. Using the Pfaffian technique, we prove that the difference in local properties between the two topologically degenerate ground states on the cylinders and on the tori decreases exponentially with increasing system size. We compute the relevant correlation length and show that it equals the correlation length of the vison operator. | The cradle of quantum spin liquids, triangular antiferromagnets show strong proclivity to magnetic order and require deliberate tuning to stabilize a spin-liquid state. In this brief review, we juxtapose recent theoretical developments that trace the parameter regime of the spin-liquid phase, with experimental results for Co-based and Yb-based triangular antiferromagnets. Unconventional spin dynamics arising from both ordered and disordered ground states is discussed, and the notion of a geometrically perfect triangular system is scrutinized to demonstrate non-trivial imperfections that may assist magnetic frustration in stabilizing dynamic spin states with peculiar excitations. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,834 |
We study the non-equilibrium dynamics of the spherical p-spin models in the scaling regime near the plateau and derive the corresponding scaling functions for the correlators. Our main result is that the matching between different time regimes fixes the aging function in the aging regime to h(t) = exp [t1 − μ]. The exponent μ is related to the one giving the length of the plateau. Interestingly 1 − μ is quickly very small when one goes away from the dynamic transition temperature in the glassy phase. This sheds new light on the interpretation of experiments and simulations where simple aging was found to be a reasonable but not perfect approximation, which could be attributed to the existence of a small but non-zero stretching exponent. | The aging of polymeric materials and the alteration of corresponding physical properties are described. -- AATA | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,835 |
The recombination and spin dynamics of excitons in colloidal CdTe nanocrystals (NCs) are studied by time-resolved photoluminescence in high magnetic fields up to 15 T and at cryogenic temperatures. The recombination decay shows a nonexponential temporal behavior, with the longest component corresponding to the dark excitons having 260 ns decay time at zero magnetic field and 4.2 K temperature. This long component shortens to 150 ns at 15 T due to the magnetic-field-induced mixing of the bright and dark exciton states. The spin dynamics, assessed through the evolution of the magnetic-field-induced circular polarization degree of the photoluminescence, has a fast component shorter than 1 ns related to the bright excitons and a slow component of 5-10 ns associated with the dark excitons. The latter shortens with increasing magnetic field, which is characteristic for a phonon-assisted spin relaxation mechanism. The relatively low saturation level of the associated magnetic-field-induced circular polarization degree of -30 % is explained by a model that suggests the CdTe NCs to constitute an ensemble of prolate and oblate NCs, both having a structural quantization axis. The exciton g-factor of 2.4-2.9 evaluated from fitting the experimental data in the frame of the suggested approach is in good agreement with the expected value for the dark excitons in CdTe NCs. | Non-magnetic colloidal nanostructures can demonstrate magnetic properties typical for diluted magnetic semiconductors because the spins of dangling bonds at their surface can act as the localized spins of magnetic ions. Here we report the observation of dangling-bond magnetic polarons (DBMPs) in 2.8-nm diameter CdSe colloidal nanocrystals (NCs). The DBMP binding energy of 7 meV is measured from the spectral shift of the emission lines under selective laser excitation. The polaron formation at low temperatures occurs by optical orientation of the dangling-bond spins (DBSs) that result from dangling-bond-assisted radiative recombination of spin-forbidden dark excitons. Modelling of the temperature dependence of the DBMP-binding energy and emission intensity shows that the DBMP is composed of a dark exciton and about 60 DBSs. The exchange integral of one DBS with the electron confined in the NC is ∼0.12 meV. | ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system... | eng_Latn | 27,836 |
We study the excitation of spin waves in magnetic insulators by the current-induced spin-transfer torque. We predict preferential excitation of surface spin waves induced by an easy-axis surface anisotropy with critical current inversely proportional to the penetration depth and surface anisotropy. The surface modes strongly reduce the critical current and enhance the excitation power of the current-induced magnetization dynamics. | A clear understanding of the temperature evolution of the longitudinal spin Seebeck effect (LSSE) in the classic Pt/yttrium iron garnet (YIG) system and its association with magnetic anisotropy is essential towards optimization of its spin-caloric functionality for spintronics applications. We report here for the first time the temperature dependences of LSSE voltage (VLSSE), magnetocrystalline anisotropy field (HK) and surface perpendicular magnetic anisotropy field (HKS) in the same Pt/YIG system. We show that on lowering temperature, the sharp drop in VLSSE and the sudden increases in HK and HKS at ~175 K are associated with the spin reorientation due to single ion anisotropy of Fe2+ ions. The VLSSE peak at ~75 K is attributed to the HKS and MS (saturation magnetization) whose peaks also occur at the same temperature. The effects of surface and bulk magnetic anisotropies are corroborated with those of thermally excited magnon number and magnon propagation length to satisfactorily explain the temperature dependence of LSSE in the Pt/YIG system. Our study also emphasizes the important roles of bulk and surface anisotropies in the LSSE in YIG and paves a new pathway for developing novel spin-caloric materials. | A stab wound to the right flank of a 24-year-old man produced immediate paralysis of both legs but spared sensation. Recovery was slow but sufficient to allow walking with a cane. Radicular artery interruption, in combination with systemic hypotension, is presumed to have caused selective watershed infarction of the spinal cord. Strokes of the spinal cord after trauma are rare, and those at a thoracic level usually represent delayed infarctions after pediatric chest or abdominal injuries. Our patient sustained an immediate and highly selective infarction. | eng_Latn | 27,837 |
The low temperature relaxation of the magnetization in molecular magnetic solids such as Fe 8 is studied using Monte Carlo simulations. A set of rate equations is then developed to understand the simulations, and the results are compared. The simulations show that the magnetization of an initially saturated sample deviates as a square-root in time at short times, as observed experimentally, and this law is derived from the rate equations analytically. | Open quantum systems are subject to interaction with their surrounding environment. In many applications, at low temperatures, quantum environments fall into two universality classes of models: Caldeira-Leggett oscillator bath models and Prokof'ev-Stamp spin bath models. The two classes are commonly recognized to be distinct and to have strikingly different effects on principal systems, except at weak coupling limits. However, I show here, in contrast, that oscillator bath models can simulate the effect of spin bath models in strong coupling limit of the spin bath. I choose parameters of the oscillator bath models such that they produce incoherent relaxation, just as in the spin bath models, with relaxation rates for a two-state system (a qubit) equivalent to those of the spin bath models in the strong coupling limit. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,838 |
The thermoelectric analog of spin-polarized tunneling, namely Seebeck spin tunneling, is a recently discovered phenomenon that arises from the spin-dependent Seebeck coefficient of a magnetic tunnel contact. In a tunnel junction with one ferromagnetic electrode and one non-magnetic electrode, a temperature difference between the two electrodes creates a spin current across the contact. Here, the basic principle and the observation of Seebeck spin tunneling are described. It is shown how it can be used to create a spin accumulation in silicon driven by a heat flow across a magnetic tunnel contact, without a charge tunnel current. The sign of the spin current depends on the direction of the heat flow, whereas its magnitude is anisotropic, i.e., dependent on the absolute orientation of the magnetization of the ferromagnet. The connection between Seebeck spin tunneling and the tunnel magneto-Seebeck effect, observed in metal magnetic tunnel junctions, is also clarified. Seebeck spin tunneling may be used to convert waste heat into useful thermal spin currents that aid or replace electrical spin current, and thereby improve the energy efficiency of spintronic devices and technologies. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. | We found a strong influence of the composition of the magnetic material on the temperature dependence of the tunneling magneto-Seebeck effect in $MgO$ based tunnel junctions. We use \textit{ab initio} alloy theory to consider different $Fe_xCo_{1-x}$ alloys for the ferromagnetic layer. Even a small change of the composition leads to strong changes in the magnitude or even in the sign of the tunneling magneto-Seebeck effect. This can explain differences between recent experimental results. In addition, changing the barrier thickness from six to ten monolayers of $MgO$ leads also to a non-trivial change of the temperature dependence. Our results emphasize that the tunneling magneto-Seebeck effect depends very crucially and is very sensitive to material parameters and show that further experimental and theoretical investigations are necessary. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,839 |
Wideband selective n-quantum excitation in the NMR of coupled spins is demonstrated for the first time. By a combination of multiple pulse averaging and phase shifts ϕ a pure n-quantum excitation operator can be produced (n=2π / ϕ). This allows enhancement of normally weak n-quantum transitions. Selective excitation of the zero- and four-quantum transitions in benzene illustrates this approach. Extensions to selective absorption of only groups of n photons in other regimes of spectroscopy are straight-forward, in principle. | We present single- and multiple-quantum correlation $J$-spectroscopy detected in zero ($<\!\!1$~$\mu$G) magnetic field using a \Rb vapor-cell magnetometer. At zero field the spectrum of ethanol appears as a mixture of \carbon isotopomers, and correlation spectroscopy is useful in separating the two composite spectra. We also identify and observe the zero-field equivalent of a double-quantum transition in ${}^{13}$C$_2$-acetic acid, and show that such transitions are of use in spectral assignment. Two-dimensional spectroscopy further improves the high resolution attained in zero-field NMR since selection rules on the coherence-transfer pathways allow for the separation of otherwise overlapping resonances into distinct cross-peaks. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,840 |
The structural and magnetic behaviors are studied in the composites (x) BiFe0.95Co0.05O3: (1-x) La0.7Ca0.3MnO3. An influence on the lattice parameters and magnetic states of BiFe0.95Co0.05O3 (BFCO) to the La0.7Ca0.3MnO3 (LCMO) are investigated. Although the variation of the relative X-ray intensity of LCMO to BFCO with composition (x) in XRD patterns and the randomly distributed small nanoparticle of LCMO (~200 nm) mixed in the large nanoparticle of BFCO (~900 nm) given by SEM images indicate an almost immiscibility of BFCO and LCMO in composites obtained by solid solution method, an obvious change of lattice parameters indicates their mutual influence on lattice structure. A detail magnetic investigation of the composites shows that the Griffiths phase is increased with increase of composition x due to the incorporation of ferromagnetism of BFCO to the paramagnetic phase of LCMO. An approximate magnetic phase diagram for the composites is established, which would be helpful for understanding the magnetic singularity of the composites with colossal magnetoresistance and multiferroics. | The eigenvalues and eigenvectors of the inverse of the susceptibility matrix are discussed for random spin systems. At a phase transition precipitated by the vanishing of the smallest eigenvalue it is shown that the corresponding eigenvector must be extended, and that the density of states must vanish at zero eigenvalue. Above the transition temperature, generalised Griffiths singularities are associated with the existence of localised states with arbitrarily small eigenvalues. For infinite spin dimensionality the eigenvalue problem is equivalent to an Anderson problem with correlated diagonal and off-diagonal disorder. | • Ni-Co-Mn oxides from spent lithium ion batteries were reused in bifunctional air electrodes. | eng_Latn | 27,841 |
In Magnetic Resonance Tomography (MRT) image contrast can be improved by adding paramagnetic relaxation agents such as lanthanide ions. Here we report on the use of highly paramagnetic isostructural Fe(III)/4f coordination clusters with a [Fe10Ln10] core to enhance relaxation. Measurements were performed over the range of (1)H Larmor frequencies of 10 MHz to 1.4 GHz in order to determine the relevant parameters for longitudinal and transverse relaxivities. Variation of the lanthanide ion allows differentiation of relaxation contributions from electronic states and molecular dynamics. We find that the transverse relaxivities increase with field, whereas the longitudinal relaxivities depend on the nature of the lanthanide. In addition, the Gd(III) analogue was selected in particular to test the interaction with tissue observed using MRT. Studies on biofilms used in waste water treatment reveal that the behaviour of the high-spin clusters is different from what is observed for common relaxation agents with respect to the penetration into the biofilms. The Fe10Gd10 cluster adheres to the surface of the biofilm better than the commercial agent Gadovist. | Selected Contents. Introduction. The hyperfine shift. Relaxation. Chemical exchange, chemical equilibria and dynamics. Transition metal ions: shift and relaxation. Magnetic coupled systems. Nuclear Overhauser effect. Two-dimensional spectra and beyond. Hints on experimental techniques. Appendix I NMR properties of nuclei. Appendix II Dipolar coupling between two spins. Appendix III Derivation of the equations for contact shift and relaxation in a simple case. Appendix IV Derivation of pseudocontact shift in the case of axial symmetry. Appendix V Relaxation by dipolar interaction between two spins. Appendix VI Calculation of (Sz): Curie's law. Appendix VII Derivation of the equations related to NOE. Appendix VIII Magnetically coupled dimers in the high-temperature limit. Appendix IX Product operators: basic tools. Appendix X Reference tables. Subject index. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,842 |
The combined effect of a lateral square superlattice potential and the Coulomb interaction on the ground state of a two-dimensional electron gas in a perpendicular magnetic field is studied for different rational values of $\Gamma$, the inverse of the number of flux quanta per unit cell of the external potential, at filling factor $\nu =1$ in Landau level $N=0.$ When Landau level mixing and disorder effects are neglected, increasing the strength $W_{0}$ of the potential induces a transition, at a critical strength $W_{0}^{\left( c\right) },$ from a uniform and fully spin polarized state to a two-dimensional charge density wave (CDW) with a meronlike spin texture at each maximum and minimum of the CDW. The collective excitations of this vortex-CDW are similar to those of the Skyrme crystal that is expected to be the ground state near filling factor $\nu =1$. In particular, a broken U(1) symmetry in the vortex-CDW results in an extra gapless phase mode that could provide a fast channel for the relaxation of nuclear spins. The average spin polarization $% S_{z}$ changes in a continuous or discontinuous manner as $W_{0}$ is increased depending on whether $\Gamma \in \left[ 1/2,1\right] $ or $\Gamma \in \left[ 0,1/2\right] .$ The phase mode and the meronlike spin texture disappear at large value of $W_{0},$ leaving as the ground state a partially spin-polarized CDW if $\Gamma \neq 1/2$ or a spin-unpolarized CDW if $\Gamma =1/2.$ | Quantum Hall Effect: Macroscopic and Mesoscopic Electron Transport.- Theories of the Fractional Quantum Hall Effect.- Magneto-optics of Composite Fermions.- Stripe and Bubble Phases in Quantum Hall Systems.- Low Dimensional Magnets.- Frustrated Quantum Magnets.- NMR Studies of Low-Dimensional Quantum Antiferromagnets.- Magnetized States of Quantum Spin Chains.- Electronic Phases of Low-Dimensional Conductors.- Two Prototypes of One-Dimensional Conductors: (TM)2X and Cuprate Spin Ladders.- Nucleation of Superconductivity in Low-Dimensional Systems Under Magnetic Fields.- Superconductivity Under High Magnetic Fields in Low-Dimensional Organic Salts.- Vortex Phases.- Colossal Magnetoresistive Oxides in High Magnetic Fields.- Half-Metallic Ferromagnets.- Effects of Electron-Electron Interactions Near the Metal-Insulator Transition in Indium-Oxide Films.- Interference Effects in Disordered Insulators.- High Resolution NMR of Biomolecules.- High-Resolution Solid-State NMR.- High Frequency EPR Spectroscopy.- Pulsed-High Field/High-Frequency EPR Spectroscopy. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,843 |
Accurate pseudocontact shifts are the basis for structural determination in solution by means of paramagnetic NMR. Separation of pseudocontact (PCS) from Fermi contact (FC) shifts from NMR data can be achieved by means of the so-called Reilley method, which is briefly critically reviewed. It encounters a relevant limitation in the case of change of crystal field parameters through the series, as determined by various processes, primarily axial ligand dynamics, or as a consequence of lanthanide contraction. We propose a simple alternative procedure to compensate for any variation (smooth or abrupt) in crystal field parameters. Four examples taken from the literature, plus the complete set of unpublished data for Ln DOTMA are discussed in detail to illustrate the power and limitation of the conventional Reilley treatment and to demonstrate the power and scope of our alternative approach. | Molecules and metal complexes with paramagnetic ground states or low-energy paramagnetic electronic excited states may exhibit profound effects due to electron paramagnetism on NMR parameters such as nuclear magnetic shielding constants and indirect nuclear spin–spin coupling. This review discusses different approaches that can be used to calculate such effects from first principles, either with or without employing fictitious spin Hamiltonian parameters. Case studies are presented, along with an overview of selected recently published computational studies of NMR chemical shifts of paramagnetic systems. | Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights. | eng_Latn | 27,844 |
Siraitia grosvenorii is a traditional Chinese medicine also as edible food. This study selected six candidate reference genes by real-time quantitative PCR, the expression stability of the candidate reference genes in the different samples was analyzed by using the software and methods of geNorm, NormFinder, BestKeeper, Delta CT method and RefFinder, reference genes for S. grosvenorii were selected for the first time. The results showed that 18SrRNA expressed most stable in all samples, was the best reference gene in the genetic analysis. The study has a guiding role for the analysis of gene expression using qRT-PCR methods, providing a suitable reference genes to ensure the results in the study on differential expressed gene in synthesis and biological pathways, also other genes of S. grosvenorii. | CYP450 plays an essential role in the development and growth of the fruits of Siraitia grosvenorii. However, little is known about the SgCYP450-4 gene in S. grosvenorii. Here, based on transcriptome data, a full-length cDNA sequence of SgCYP450-4 was cloned by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid-amplification of cDNA ends (RACE) strategies. SgCYP450-4 is 1677 bp in length (GenBank accession No. AEM42985.1) and contains a complete open reading frame (ORF) of 1422 bp. The deduced protein was composed of 473 amino acids, the molecular weight is 54.01 kDa, the theoretical isoelectric point (PI) is 8.8, and the protein was predicted to possess cytochrome P450 domains. SgCYP450-4 gene was highly expressed in root, diploid fruit and fruit treated with hormone and pollination. At 10 days after treatment with pollination and hormones, the expression of SgCYP450-4 had the highest level and then decreased over time, which was consistent with the development of fruits of S. Grosvenorii. Hormonal treatment could significantly induce the expression of SgCYP450-4. These results provide a reference for regulation of fruit development and the use of parthenocarpy to generate seedless fruit, and provide a scientific basis for the production of growth regulator application agents. | Sr2RuO4 is the best candidate for spin-triplet superconductivity, an unusual and elusive superconducting state of fundamental importance. In the last three decades, Sr2RuO4 has been very carefully studied and despite its apparent simplicity when compared with strongly correlated high-T ::: c cuprates, for which the pairing symmetry is understood, there is no scenario that can explain all the major experimental observations, a conundrum that has generated tremendous interest. Here, we present a density-functional-based analysis of magnetic interactions in Sr2RuO4 and discuss the role of magnetic anisotropy in its unconventional superconductivity. Our goal is twofold. First, we access the possibility of the superconducting order parameter rotation in an external magnetic field of 200 Oe, and conclude that the spin–orbit interaction in this material is several orders of magnitude too strong to be consistent with this hypothesis. Thus, the observed invariance of the Knight shift across T ::: c has no plausible explanation, and casts doubt on using the Knight shift as an ultimate litmus paper for the pairing symmetry. Second, we propose a quantitative double-exchange-like model for combining itinerant fermions with an anisotropic Heisenberg magnetic Hamiltonian. This model is complementary to the Hubbard-model-based calculations published so far, and forms an alternative framework for exploring superconducting symmetry in Sr2RuO4. As an example, we use this model to analyze the degeneracy between various p-triplet states in the simplest mean-field approximation, and show that it splits into a single and two doublets with the ground state defined by the competition between the “Ising” and “compass” anisotropic terms. A new framework for analysing the role of magnetic interactions on the unconventional superconductivity in strontium ruthenate. Strontium ruthenate is an unconventional superconductor that used to be touted a potential three-dimensional analogue of Helium-3, as it was thought to have the same type of chiral p-wave pairing. It is now widely accepted that this is not the case, but many questions remain over the exact nature of the pairing, particularly regarding the role of magnetic interactions. An international team of researchers led by Bongjae Kim and Sergii Khmelevskyi from the University of Vienna and Vienna University of Technology now present a framework that can incorporate the leading isotropic and anisotropic magnetic interactions in a different but complimentary way to the widely used Hubbard-model, providing an alternative way of exploring the superconducting pairing symmetry. | eng_Latn | 27,845 |
The nontrivial feature and penetration depth of the topological surface states (TSS) in SmB_{6} were studied via spin pumping. The experiments used SmB_{6} thin films grown on the bulk magnetic insulator Y_{3}Fe_{5}O_{12} (YIG). Upon the excitation of magnetization precession in the YIG, a spin current is generated in the SmB_{6} that produces, via spin-orbit coupling, a lateral electrical voltage in the film. This spin-pumping voltage signal becomes considerably stronger as the temperature decreases from 150 to 10 K, and such an enhancement most likely originates from the spin-momentum locking of the TSS and may thereby serve as evidence for the nontrivial nature of the TSS. The voltage data also show a unique film thickness dependence that suggests a TSS depth of ∼32 nm. The spin-pumping results are supported by transport measurements and analyses using a tight binding model. | The Kondo insulator compound SmB6 has emerged as a strong candidate for the realization of a topologically nontrivial state in a strongly correlated system, a topological Kondo insulator, which can be a novel platform for investigating the interplay between nontrivial topology and emergent correlation driven phenomena in solid state systems. Electronic transport measurements on this material, however, so far showed only the robust surface dominated charge conduction at low temperatures, lacking evidence of its connection to the topological nature by showing, for example, spin polarization due to spin momentum locking. Here, we find evidence for surface state spin polarization by electrical detection of a current induced spin chemical potential difference on the surface of a SmB6 single crystal. We clearly observe a surface dominated spin voltage, which is proportional to the projection of the spin polarization onto the contact magnetization, is determined by the direction and magnitude of the charge current and is strongly temperature dependent due to the crossover from surface to bulk conduction. We estimate the lower bound of the surface state net spin polarization as 15 percent based on the quantum transport model providing direct evidence that SmB6 supports metallic spin helical surface states. | The characterization of stormwater runoff on urbanized surfaces by means of comparison between experimental data and simulations is a strict requirement for a sustainable management of urban sewer systems. A monitoring campaign was carried out within a residential area in Puglia (Southern Italy) in order to collect and evaluate quantity and quality data. A strong correlation was observed between COD (Chemical Oxygen Demand) and TSS (Total Suspended Solid) concentrations, whose values exceed water quality standards. TSS was used for calibration of Storm Water Management Model (SWMM) which was then validated with reference to the pollutograph’s shape and the peak-time. The first flush phenomenon occurrence was also investigated by looking at the distribution of pollutant mass vs. volume in stormwater discharges, using the so-called “M(V) curves”. Results show that on average the first 30% of that washed off carries 60% of TSS and provides important information for the design of efficient systems for first flush treatment. | eng_Latn | 27,846 |
Comparing experimental data for high-${\mathit{T}}_{\mathit{c}}$ cuprate superconductors with numerical results for electronic models, it is becoming apparent that a hopping along the plaquette diagonals has to be included to obtain quantitative agreement. However, the values for ${\mathit{t}}^{\ensuremath{'}}$ discussed in the literature were obtained comparing theoretical results in the weak-coupling limit with photoemission data and band-structure calculations. The goal of this paper is to study how ${\mathit{t}}^{\ensuremath{'}}$ gets renormalized as the interaction between electrons, U, increases. For this purpose, the effect of adding a bare diagonal hopping ${\mathit{t}}^{\ensuremath{'}}$ to the two-dimensional Hubbard model Hamiltonian is investigated using numerical techniques. Spin-spin correlations, n(k), 〈n〉 vs \ensuremath{\mu}, and local magnetic moments are studied for several values of U/t and the electronic density. The spectral function A(k,\ensuremath{\omega}) is also discussed. We introduce a criterion to determine probable locations of Fermi surfaces at zero temperature. In general, we conclude that it is very dangerous to extract a bare parameter of the Hamiltonian (${\mathit{t}}^{\ensuremath{'}}$) from photoemission spectroscopy data where renormalized parameters play the important role. | Based on Green’s function formalism, we investigate the effects of interdot and lead-dot coupling on the charge and spin current through a triple-quantum-dot ring structure, where each dot is connected to a semi-infinite lead. The results show that in weak (strong) interdot coupling regime, by increasing the interdot coupling strength ${t}$ , the output current increases (decreases), approaching a maximum (nearly constant) value. Besides, the on-site energy of quantum dots (QDs), and also the electron–electron interaction termed as a coulomb blockade one, can be effective on the output current versus ${t}$ . In addition, by increasing the lead-dot coupling strength, the occupation number of the corresponding QD decreases and so the current through connected lead, increases. Moreover, by tuning the parameters such as Rashba spin-orbit interaction, on-site energies of dots and magnetic flux inside the ring, one can control and manipulate the spin-dependent output currents as a function of the lead-dot and interdot coupling strength to obtain a pure spin current, and also reveal the spin-flip effect through the output lead, therefore, the proposed device can be useful in various spintronic nanoscale applications. | AnO(n 3) mathematically non-iterative heuristic procedure that needs no artificial variable is presented for solving linear programming problems. An optimality test is included. Numerical experiments depict the utility/scope of such a procedure. | eng_Latn | 27,847 |
The spin-1/2 anisotropic Heisenberg antiferromagnet is studied at [ital T]=0 on the triangle lattice via numerical diagonalization for system sizes up to [ital N]=36 sites. Extrapolation to the thermodynamic limit suggests that the isotropic system possesses no, or very small, [radical]3 [times] [radical]3 magnetic order; no helical or chiral order; and spin-spin correlations consistent with that of a critical phase. For [ital XY]-like anisotropy there is long-ranged [radical]3 [times] [radical]3 magnetic order. In contrast to bipartite lattices, the standard first- and second-order spin-wave theories are not quantitatively accurate. Excitation energy gaps suggest that the lowest lying excitations for the isotropic point are not spin-flip excitations in the thermodynamic limit. The results for the isotropic point appear to agree with recent series expansion, large-[ital N] expansion, and the original resonating valence bond picture of Anderson, although they cannot be considered as conclusive evidence supporting any of these theories. | Plateaux in the magnetization curves of the square-, triangular- and hexagonal-lattice spin-1/2 XXZ antiferromagnet are investigated. One finds a zero-magnetization plateau (corresponding to a spin gap) on the square and hexagonal lattice with Ising-like anisotropies, and a plateau with one-third of the saturation magnetization on the triangular lattice which survives a small amount of easy-plane anisotropy. Here we start with transfer-matrix computations for the Ising limit and continue with series in the XXZ anisotropy for plateau boundaries using the ground states of the Ising limit. The main focus is then a numerical computation of the magnetization curves with anisotropies in the vicinity of the isotropic situation. Finally, we discuss the universality class associated with the asymptotic behaviour of the magnetization curve close to saturation, as observed numerically in two and higher dimensions. | The article presents the fundamentals of the cosmic geophysics (representing the deterministic thermohydrogravidynamic theory intended for earthquakes prediction) based on the author's generalized differential formulation of the first law of thermodynamics extending the classical Gibbs' formulation by taking into account (along with the classical infinitesimal change of heat and the classical infinitesimal change of the internal energy ) the infinitesimal increment of the macroscopic kinetic energy , the infinitesimal increment of the gravitational potential energy , the generalized expression for the infinitesimal work done by the nonpotential terrestrial stress forces (determined by the symmetric stress tensor ) acting on the boundary of the continuum region , and the infinitesimal increment of energy due to the cosmic and terrestrial nonstationary energy gravitational influence on the continuum region during the infinitesimal time . Based on the established generalized differential formulation of the first law of thermodynamics, the author explains the founded cosmic energy gravitational genesis of the strong Chinese 2008 and the strong Japanese 2011 earthquakes. | eng_Latn | 27,848 |
We study the nonlinear dynamics of a site-dependent Heisenberg ferromagnetic spin chain with Gilbert damping in the continuum limit and its associated dynamics which is governed by an inhomogeneous generalized higher order nonlinear Schrodinger equation. The effect of inhomogeneity was understood by carrying out a multiple perturbation analysis and the coupled evolution equations for the velocity and amplitude of the soliton were solved using the Jacobi elliptic function method. The evolution of the amplitude and velocity of the soliton leads to magnetization reversal via flipping of solitons in the ferromagnetic medium. Finally, we have also constructed the perturbed soliton solutions. | Information density and switching of magnetization offers an interesting physical phenomenon which invoke magneto-optical techniques employed on the magnetic medium. In this paper, we explore the soliton assisted magnetization reversal in the nanosecond regime in the theoretical framework of the Landau–Lifshitz–Maxwell (LLM) model. Starting from the Landau–Lifshitz equation, we employ the reductive perturbation method to derive an inhomogeneous nonlinear Schrodinger equation, governing the nonlinear spin excitations of a site-dependent anisotropic ferromagnetic medium under the influence of electromagnetic (EM) field in the classical continuum limit. From the results, it is found that the soliton undergoes a flipping thereby indicating the occurrence of magnetization reversal behavior in the nanoscale regime due to the presence of inhomogeneity in the form of a linear function. Besides, the spin components of magnetization are also evolved as soliton spin excitations. | Information density and switching of magnetization offers an interesting physical phenomenon which invoke magneto-optical techniques employed on the magnetic medium. In this paper, we explore the soliton assisted magnetization reversal in the nanosecond regime in the theoretical framework of the Landau–Lifshitz–Maxwell (LLM) model. Starting from the Landau–Lifshitz equation, we employ the reductive perturbation method to derive an inhomogeneous nonlinear Schrodinger equation, governing the nonlinear spin excitations of a site-dependent anisotropic ferromagnetic medium under the influence of electromagnetic (EM) field in the classical continuum limit. From the results, it is found that the soliton undergoes a flipping thereby indicating the occurrence of magnetization reversal behavior in the nanoscale regime due to the presence of inhomogeneity in the form of a linear function. Besides, the spin components of magnetization are also evolved as soliton spin excitations. | eng_Latn | 27,849 |
This is extended version of a previously submitted paper, in which special solutions of the Hartree-Fock (HF) problem for Coulomb interacting electrons, being described by a simple model of the Cu-O planes in La2CuO4, are presented. One of the mean field states obtained, is able to predict some of the basic properties of this material, such as its insulator character and the antiferromagnetic order. The natural appearance of pseudogaps in some states of this compound is also indicated by another of the HF states obtained. These surprising results follow after eliminating spin and crystal symmetry restrictions which are usually imposed on the single particle HF orbitals, by means of employing a rotational invariant formulation of the HF scheme which was originally introduced by Dirac. Therefore, it is exemplified how, up to now being considered strong correlation effects, can be described by improving the HF solution of the physical systems. In other words, defining the correlation effects as such ones shown by the physical system and which are not predicted by the best HF (lowest energy) solution, allows to explain currently assumed as strong correlation properties, as simple mean field ones. The discussion also helps to clarify the role of the antiferromagnetism and pseudogaps in the physics of the HTSC materials and indicates a promising way to start conciliating the Mott and Slater pictures for the description of the transition metal oxides and other strongly correlated electron systems. | A general survey of the idea of the metal-nonmetal transition is given with particular emphasis to the following points: (a) is the transition of first order; (b) can one observe the transition; and (c) how is the transition affected when it occurs in ionic lattices or polar liquids. | The aim of this study is to report five cases of children treated with an interceptive technique utilizing ALF (Advanced Light Force) functional orthodontic appliances in anterior and/or posterior cross bites in primary and early mixed dentition. | eng_Latn | 27,850 |
The spin polarization at the surface of Fe nanoclusters has been probed using a spin-polarized metastable helium beam. The clusters, produced in a gas aggregation source, display a lognormal size distribution with a peak centered at ~11 nm. Varying coverages of both spheroid- and cuboid-shaped particles were concomitantly deposited onto clean Si(111) substrates for investigation with the extremely surface sensitive technique of metastable de-excitation spectroscopy (MDS). A nominal cluster coverage of 8 ? yielded a maximum asymmetry of ~10% in the ejected electron yield for He spins aligned parallel and anti-parallel to the magnetization direction of the clusters. When compared to values obtained from epitaxial Fe films on various substrates, the measured asymmetry suggests an enhancement in the surface spin polarization, as theoretically proposed. The atomic structure of the clusters and their topography on the Si(111) substrates were studied with transmission and scanning electron microscopy. | Increasing attention has been focused on the magnetic behavior of nanoparticles with diameters of 1-5 nm (approximately 50-5000 atoms). In this size range fundamental magnetic parameters such as the orbital and spin magnetic moments per atom deviate significantly from bulk values, and studying clusters addresses fundamental problems in mesoscopic magnetism, which is not as well understood as in either the atomic or the bulk regimes. There is also a growing realization of the enormous industrial potential of materials built by depositing preformed nanoclusters instead of atoms. If the clusters are size-selected and deposited in conjunction with an atomic vapor of a matrix material, it is possible to produce granular films in which there is independent control over the particle size and volume fraction. Using this technique, it also becomes possible to make granular mixtures of miscible materials. This unprecendented degree of control over the properties of the films holds the promise of new magnetic materials with "engineered properties." To fully realize this potential requires a greater understanding of not only the individual particles, but also how they interact in dense assemblies. There has been great progress in understanding some aspects of the magnetic behavior of nanoclusters and cluster-assembled materials. The mechanisms that generate spin and orbital moments that are enhanced by up to 36 and 200%, respectively, relative to the bulk in isolated clusters are well understood as is the dynamical behavior of the magnetic moment. Not so well understood is the observed magnetic anisotropy, which often has a different symmetry than the bulk. In dense assemblies, the nature of the interparticle coupling and the relative importance of dipolar and exchange interactions also require further research. | We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero. | eng_Latn | 27,851 |
Decoherence of quantum systems due to uncontrolled fluctuations of the environment presents fundamental obstacles in quantum science. `Clock' transitions which are insensitive to such fluctuations are used to improve coherence, however, they are not present in all systems or for arbitrary system parameters. Here, we create a trio of synthetic clock transitions using continuous dynamical decoupling in a spin-1 Bose-Einstein condensate in which we observe a reduction of sensitivity to magnetic field noise of up to four orders of magnitude; this work complements the parallel work by Anderson et al. (submitted, 2017). In addition, using a concatenated scheme, we demonstrate suppression of sensitivity to fluctuations in our control fields. These field-insensitive states represent an ideal foundation for the next generation of cold atom experiments focused on fragile many-body phases relevant to quantum magnetism, artificial gauge fields, and topological matter. | Topological order can be found in a wide range of physical systems, from crystalline solids, photonic meta-materials and even atmospheric waves to optomechanic, acoustic and atomic systems. Topological systems are a robust foundation for creating quantized channels for transporting electrical current, light, and atmospheric disturbances. These topological effects are quantified in terms of integer-valued invariants, such as the Chern number, applicable to the quantum Hall effect, or the $\mathbb{Z}_2$ invariant suitable for topological insulators. Here we engineered Rashba spin-orbit coupling for a cold atomic gas giving non-trivial topology, without the underlying crystalline structure that conventionally yields integer Chern numbers. We validated our procedure by spectroscopically measuring the full dispersion relation, that contained only a single Dirac point. We measured the quantum geometry underlying the dispersion relation and obtained the topological index using matter-wave interferometry. In contrast to crystalline materials, where topological indices take on integer values, our continuum system reveals an unconventional half-integer Chern number, potentially implying new forms of topological transport. | The sensitivity of an overlapped-tube cryogenic current comparator (CCC) has been calculated including the effect of an external shield. Dimensions of the shield, tube and pick-up coil can be optimised to give maximum sensitivity. Improvements in sensitivity by a factor of two or three are possible for a typical design. | eng_Latn | 27,852 |
We investigate the ground states of 1D continuum models having short-range ferromagnetic type interactions and a wide class of competing longer-range antiferromagnetic type interactions. The model is defined in terms of an energy functional, which can be thought of as the Hamiltonian of a coarse-grained microscopic system or as a mesoscopic free energy functional describing various materials. We prove that the ground state is simple periodic whatever the prescribed total magnetization might be. Previous studies of this model of frustrated systems assumed this simple periodicity but, as in many examples in condensed matter physics, it is neither obvious nor always true that ground states do not have a more complicated, or even chaotic structure. | We prove that a system of discrete 2D in-plane dipoles with four possible orientations, interacting via a 3D dipole-dipole interaction plus a nearest neighbor ferromagnetic term, has periodic striped ground states. As the strength of the ferromagnetic term is increased, the size of the stripes in the ground state increases, becoming infinite, i.e., giving a ferromagentic ground state, when the ferromagentic interaction exceeds a certain critical value. We also give a rigorous proof of the reorientation transition in the ground state of a 2D system of discrete dipoles with six possible orientations, interacting via a 3D dipole-dipole interaction plus a nearest neighbor antiferromagnetic term. As the strength of the antiferromagnetic term is increased the ground state flips from being striped and in-plane to being staggered and out-of-plane. An example of a rotator model with a sinusoidal ground state is also discussed. | This article provides a postcolonial critique of power-resistance dialectics among outsourced call center workers in India. A constructivist grounded theory analysis of focus group and interview data with 65 participants reveals how microresistance intersects with global capitalism in ways that both accommodate and rupture Western discourses. These discursive and material intersectionalities are made visible through employees' processes of (1) aping the West, (2) articulating new logics and demonstrating Indian sensibilities, and (3) embracing a new life. The themes primarily reveal how the employees rupture the essentialist image of the other and challenge the dominant logic of neoliberalism. | eng_Latn | 27,853 |
The rotating magnetocaloric effect (RMCE) is a new issue in the field of magnetic refrigeration. We have explored this subject on the two-dimensional (2D) enantiopure {[MnII(R-mpm)2]2[NbIV(CN)8]}·4H2O (where mpm = α-methyl-2-pyridinemethanol) coordination ferrimagnet. In this study, the magnetic and magnetocaloric properties of single crystals were investigated along the bc//H easy plane and the a*//H hard axis. The observed small easy plane anisotropy is due to the dipole-dipole interactions. For fields higher than 0.5 T, no significant difference in the magnetocaloric effect between both geometries was noticed. The maximal magnetic entropy change for conventional effect was observed at 32 K and the magnetic field change μ0ΔH = 5.0 T attaining the value of ∼5 J mol-1 K-1. The obtained maximal value of -ΔSm is comparable to previously reported results for polycrystalline octacyanidoniobate-based bimetallic coordination polymers. A substantial anisotropy of magnetocaloric effect between the easy plane and hard axis appears in low fields. This includes the presence of inverse magnetocaloric effect only for the a*//H direction. The difference between both geometries was used to study the rotating magnetocaloric effect. We show that the inverse part of magnetocaloric effect can be used to enhance the rotating magnetic entropy change up to 51%. This finding is of key importance for searching efficient materials for RMCE. | Octacyanometallate-based compounds displaying a rich pallet of interesting physical and chemical properties, are key materials in the field of molecular magnetism. The [M(CN)8]n− complexes, (M = WV, MoV, NbIV), are universal building blocks as they lead to various spatial structures, depending on the surrounding ligands and the choice of the metal ion. One of the functionalities of the octacyanometallate-based coordination polymers or clusters is the magnetocaloric effect (MCE), consisting in a change of the material temperature upon the application of a magnetic field. In this review, we focus on different approaches to MCE investigation. We present examples of magnetic entropy change ΔSm and adiabatic temperature change ΔTad, determined using calorimetric measurements supplemented with the algebraic extrapolation of the data down to 0 K. At the field change of 5T, the compound built of high spin clusters Ni9[W(CN)8]6 showed a maximum value of −ΔSm equal to 18.38 J·K−1 mol−1 at 4.3 K, while the corresponding maximum ΔTad = 4.6 K was attained at 2.2 K. These values revealed that this molecular material may be treated as a possible candidate for cryogenic magnetic cooling. Values obtained for ferrimagnetic polymers at temperatures close to their magnetic ordering temperatures, Tc, were lower, i.e., −ΔSm = 6.83 J·K−1 mol−1 (ΔTad = 1.42 K) and −ΔSm = 4.9 J·K−1 mol−1 (ΔTad = 2 K) for {[MnII(pyrazole)4]2[NbIV(CN)8]·4H2O}n and{[FeII(pyrazole)4]2[NbIV(CN)8]·4H2O}n, respectively. MCE results have been obtained also for other -[Nb(CN)8]-based manganese polymers, showing significant Tc dependence on pressure or the remarkable magnetic sponge behaviour. Using the data obtained for compounds with different Tc, due to dissimilar ligands or other phase of the material, the ΔSm ~ Tc−2/3 relation stemming from the molecular field theory was confirmed. The characteristic index n in the ΔSm ~ ΔHn dependence, and the critical exponents, related to n, were determined, pointing to the 3D Heisenberg model as the most adequate for the description of these particular compounds. At last, results of the rotating magnetocaloric effect (RMCE), which is a new technique efficient in the case of layered magnetic systems, are presented. Data have been obtained and discussed for single crystals of two 2D molecular magnets: ferrimagnetic {MnII(R-mpm)2]2[NbIV(CN)8]}∙4H2O (mpm = α-methyl-2-pyridinemethanol) and a strongly anisotropic (tetren)Cu4[W(CN)8]4 bilayered magnet showing the topological Berezinskii-Kosterlitz-Thouless transition. | We investigate cosmologies where the accelerated expansion of the Universe is driven by a field with an anisotropic equation of state. We model such scenarios within the Bianchi I framework, introducing two skewness parameters to quantify the deviation of pressure from isotropy. We study the dynamics of the background expansion in these models. A special case of anisotropic cosmological constant is analyzed in detail. The anisotropic expansion is then confronted with the redshift and angular distribution of the supernovae type Ia. In addition, we investigate the effects on the cosmic microwave background (CMB) anisotropies for which the main signature appears to be a quadrupole contribution. We find that the two skewness parameters can be very well constrained. Tightest bounds are imposed by the CMB quadrupole, but there are anisotropic models which avoid this bound completely. Within these bounds, the anisotropy can be beneficial as a potential explanation of various anomalous cosmological observations, especially in the CMB at the largest angles. We also consider the dynamics of linear perturbations in these models. The covariant approach is used to derive the general evolution equations for cosmological perturbations taking into account imperfect sources in an anisotropic background. The implications for the galaxy formation are then studied. These results might help to make contact between the observed anomalies in CMB and large scale structure and fundamental theories exhibiting Lorentz violation. | eng_Latn | 27,854 |
New 50 Hz superconducting power supply for a 2 kA DC magnet | A new superconducting power supply able to operate directly from the mains voltage at a frequency of 50- 60 Hz is under development in our institutes. It will be applied to power a separator magnet for iron ore recycling. The supply consists of a full wave superconducting converter, a 'cold' protection system, and control and measuring units. Typical design values of the device are: output current of 1-2kA, voltage of 1-0.5 V; input current of 7 A, voltage of 220 V and frequency of 50 Hz; an efficiency better than 96%. The high current part of the supply finally will be placed in the same cryostat as the separator magnet. The basic concept of the device is presented in the paper. | Abstract A large-scale parallel loop cluster quantum Monte Carlo simulation is presented. On 24,576 nodes of the K computer, one loop cluster Monte Carlo update of the world-line configuration of the S = 1 ∕ 2 antiferromagnetic Heisenberg chain with 2 . 6 × 1 0 6 spins at inverse temperature 3 . 1 × 1 0 5 is executed in about 8.62 s, in which global union-find cluster identification on a graph of about 1.1 trillion vertices and edges is performed. By combining the nonlocal global updates and the large-scale parallelization, we have virtually achieved about 1 0 13 -fold speed-up from the conventional local update Monte Carlo simulation performed on a single core. We have estimated successfully the antiferromagnetic correlation length and the magnitude of the first excitation gap of the S = 4 antiferromagnetic Heisenberg chain for the first time as ξ = 1 . 040 ( 7 ) × 1 0 4 and Δ = 7 . 99 ( 5 ) × 1 0 − 4 , respectively. | eng_Latn | 27,855 |
On electron confinement effects and the ultimate size reduction in semiconductor devices | Three-dimensional electron confinements cause a blue shift of the fundamental band gap and a size-induced metal-insulator transition. These quantum-size effects are expected in confinements with diameters up to the order of 10 and 100 nm at room temperature, in metals and semiconductors, respectively. The size effect can markedly be enhanced by an additional phonon confinement which is omnipresent in isolated sub-micrometre crystals. Confinement effects represent the limitation for the ultra-large-scale integration. | Abstract The properties of superfluid 3 He as a well-studied model system of unconventional superfluidity are reviewed. This will include a discussion of BCS theory extended to spin triplet p-wave states, the nodal structure of the energy spectrum and its implications for the thermodynamic and transport properties. Similarities with the model states proposed for the heavy fermion and high T c cuprate superconductors will be pointed out. Then, the existence of textures, vortices and other topological defects in the order parameter field of s- 3 He is discussed and contrasted with unconventional superconductivity in metals. Order parameter collective modes in s- 3 He and their possible counterparts in superconductors are considered. The role of the electric charge in superconductors and its coupling to the electromagnetic field will be analyzed. The last part will cover some recent results on nonlocal and nonlinear corrections to the magnetic penetration depth. | eng_Latn | 27,856 |
Monte Carlo study of transient states of order inYBa2Cu3Oz | Monte Carlo simulations of oxygen ordering in the YBa{sub 2}Cu{sub 3}O{sub {ital z}} system have been performed using a two-dimensional anisotropic Ising model. In agreement with experimental findings, transient phases are obtained at low temperatures. Observed structures are investigated, and the kinetics of their domain formation is described. The convergence of the system is seen to be exceptionally slow, and the rate of domain evolution is found to increase with decreasing oxygen content. The implications of these findings on the development of a complete theoretical ordering model for this system are discussed. | ABSTRACTLong-term travel behavior is difficult to observe and explain and even more difficult to forecast. This paper proposes an approach based on stochastic state equations to describe the gradua... | eng_Latn | 27,857 |
The green function method in the theory of nuclear and electron spin polarization. II. The first approximation and its application in the CIDEP theory | Abstract The present paper deals with a further development of the method of calculating nuclear and electron spin polarization based on the Green function formalism specifying the character of the relative motion in a pair of radical centers. In the first approximation with respect to the exchange interaction influence the calculations of the desired quantities are reduced to matrix operations. A theory of chemical polarization of electrons serves to illustrate the method. Calculations of this effect in micellar radical pairs are performed. It is shown that quantum oscillations are possible here depending on the magnitude of the external magnetic field induction. | In order to improve Q factor of inductor and optimize efficiently by synthetically considering multi-variables,a method called GP(Geometric Programming)optimization was used to get the best quality factor of spiral inductor.By analyzing the physical model of inductor through matlab,several variables which may affect the quality factor of inductor were found.With these variables and identified design requirements,GP modeling and optimization can begin.Simulation results show that compared with genetic method and image method,GP method can improve the quality factor of 14.5%and 20.2%. | eng_Latn | 27,858 |
Electron spin resonance and its applications | The method of electron spin resonance spectroscopy for studying free radicals and related materials is outlined and the basic parts of the theory are given. Some typical spectrometers are indicated and details are given of the arrangement of samples of different kinds. Three systems are discussed in some detail, as examples, namely the spectrum of a free radical in irradiated alanine, the semiquinone spectrum in solution and the haemoglobin crystal structure problem. Reference is made to applications in biology and related fields; subjects of special importance include radiobiology, photosynthesis, enzymic oxidation and nucleic acid complexes. | Using the Stevens–Tiersten equation for slowly varying thickness modes in doubly rotated quartz plate piezoelectric resonators, we determine optimal electrode shape and size for these resonators. The electrodes obtained are optimal in that they satisfy Bechmann’s number in every direction. | eng_Latn | 27,859 |
Simplified Automated Method for Determination of Urinary or Serum Uric Acid, Based on Reduction of Ferric-Phenanthroline Complex | We describe an automated colorimetric method for determination of uric acid in serum or urine by use of an AutoAnalyzer II or SMA 12/60 (Technicon Corp.). The method depends on reduction of a ferric-phenanthroline complex by uric acid under acidic conditions to a ferrous-phenanthroline complex, which absorbs at 505 nm. Advantages of this method over other methods now in use are that color and concentration are linearly related (to 20 mg/100 ml); aqueous reagents are easily prepared, stable, and inexpensive; and interference from ascorbic acid has been eliminated by use of an alkaline copper-containing diluent. The analysis is also free of interference from glucose, creatinine, glutathione, salicylates and hemoglobin. Correlation with results of the Technicon phosphotungstic acid reduction method is excellent ( r = .996). Correlation with results of an automated uricase method is satisfactory ( r = .979). Recovery of uric acid was 101% over a wide concentration range. | The magnetically ordered phase of body-centered tetragonal UAu$_2$Si$_2$ was explored through $^{29}$Si-NMR experiments. The field-swept NMR spectra show asymmetric peak splitting below magnetic phase transition temperature, $T_{\rm m}$ = 20 K. This splitting is well explained by the occurrence of a magnetic order with propagation vector of $q$ = (2/3, 0, 0) and magnetic moments pointing parallel to the tetragonal [001] axis, offering evidence for uncompensated"up-up-down"-type antiferromagnetic ordering with a spontaneous [001] magnetization component. A symmetry analysis of the hyperfine-coupling tensor with phenomenological corrections including orbital and dipolar-field contributions yields the magnitude of the ordered moment to be approximately 1.4 $\pm$ 0.2 Bohr magneton per uranium ion, and evaluates the site-dependent hyperfine-coupling constants. | eng_Latn | 27,860 |
Effect of NNN Site Si/Al Substitution on the Acid Strength: Mordenite | The acidity variations upon Si/Al substitution at NNN sites were calculated for mordenite by the ab initio molecular orbital method. The conclusions obtained from our previous work on faujasite hold with mordenite, e.g., the effects of Si/Al substitution at NNN sites on the acid strength are not uniform. Mordenite was synthesized with various Si/Al ratios and the acidic properties were examined by means of ammonia adsorption calorimetry. The analysis of the experimental results based on the binomial distribution of Al indicates that not only 0NNN sites but some of 1NNN, 2NNN, etc. should also be strong acid sites, which is consistent with the calculation. | Abstract The fabrication of high-quality Heusler alloy films with clear martensitic transformation is a challenging issue in the field of magnetic shape memory alloys. Here, flexible Mn-rich Ni–Mn–Sn (Mn49.9Ni40.4Sn9.7) thin films are successfully synthesized by pulsed laser deposition on mica substrates using Ti as buffer layer. XRD analysis reveals that films exhibit austenitic phase with L21 structure at room temperature. The surface morphology indicates polycrystalline structure of fine grains with size of about 60 nm and smooth surface with roughness of less than 1 nm. The temperature dependent magnetization measurement clearly confirms the existence of first-order martensitic transformation. Exchange bias was observed below 70 K with maximum exchange bias field of 148 Oe at 20 K, which is attributed to the exchange coupling between the coexisting antiferromagnetic and ferromagnetic phases due to the various occupations of Mn atoms. | eng_Latn | 27,861 |
Tuning magnetic properties of antiferromagnetic chains by exchange interactions: ab initio studies | The possibility of using exchange interactions to manipulate the spin state of an antiferromagnetic nanostructure is explored using ab initio calculations. By considering M (M = Mn, Fe, Co) mono-atomic chains supported on Cu2N islands on a Cu(001) surface as a model system, it is demonstrated that two indistinguishable Neel states of an antiferromagnetic chain can be tailored into a preferred state by the exchange interaction with a magnetic STM tip. The magnitude and direction of the anisotropy for antiferromagnetic chains can also be tuned by exchange coupling upon varying the tip–chain separation. | This letter suggests a new way to investigate 3-D chaos in spatial and frequency domains simultaneously. After spatially decomposing the Lorenz attractor into two separate scrolls with peaked spectra and a 1-D discrete-time zero-crossing series with a wide-band spectrum, it is found that the Lorenz chaotic attractor has an inherent frequency uniquely determined by the three system parameters. This result implies that chaos in the Lorenz attractor is mainly exhibited when the trajectory crosses from one scroll to another, not within the two scrolls. This is also true for some other double-scroll Lorenz-like chaotic attractors, such as Chua's attractor. Some possible applications of the inherent frequency and the spatial decomposition are also discussed. | eng_Latn | 27,862 |
Structure of negatively charged muonium in n-type GaAs. | Muon level-crossing resonance and muon-spin-rotation measurements on heavily doped {ital n}-type GaAs:Si and GaAs:Te show that the majority of positive muons implanted at room temperature form an isolated diamagnetic muonium center located at a high-symmetry site with Ga neighbors along the {l_angle}111{r_angle} direction(s). These experiments, together with theoretical considerations, imply that negatively charged muonium is at or near the tetrahedral interstitial site with four Ga nearest-neighbor atoms. Except for zero-point energy differences, these results should model negatively charged isolated hydrogen in GaAs. | We present a computational study of 2$p$ core-level X-ray photoemission spectra of transition metal monoxides MO (M=Ni, Co, Mn) and sesquioxides M$_2$O$_3$ (M=V, Cr, Fe) using a theoretical framework based on the local-density approximation (LDA) $+$ dynamical mean-field theory (DMFT). We find a very good description of the fine spectral features, which improves considerably over the conventional cluster model. We analyze the role of the non-local screening and its relationship to the long-range magnetic order and the lattice geometry. Our results reveal the potential of the present method for the analysis and interpretation of the modern high-energy-resolution experiments. | eng_Latn | 27,863 |
Dumbbell Rattling in Thermoelectric Zinc Antimony | Inelastic neutron scattering measurements on thermoelectric Zn{sub 4}Sb{sub 3} reveal a dominant soft local phonon mode at 5.3(1) meV. The form factor of this local mode is characteristic for dumbbells vibrating preferably along the dumbbell axis and can be related to a vibration of Sb dimers along the c axis. The Lorentzian width of the mode corresponds to short phonon lifetimes of 0.39(2) ps and yields an estimate of the thermal conductivity that agrees quantitatively with recent steady state measurements. Heat capacity measurements are consistent with an Einstein mode model describing the local Sb-dimer rattling mode with an Einstein temperature of 62(1) K. Our study suggests that soft localized phonon modes in crystalline solids are not restricted to cagelike structures and are likely to be a universal feature of good thermoelectric materials. | Zeehan's Silver-Lead orebody - Natural Phenomenon - Archival/Heritage Resources - Companion to Tasmanian History - NAME is a biographical, bibliographical and archival database of SUBJECT with links to related articles and images. ADD MORE DESCRIPTION AS REQUIRED | eng_Latn | 27,864 |
On the magnetic anomaly in ErFe3 at 47K | The low temperature anomaly in ErFe3 is examined within the context of the point charge crystal field model. It is argued that the rearrangement of the c and h iron atoms, believed to occur at 47K, is due to competition between the two crystallographically inequivalent RE sites in minimising the free energy of the crystal. In particular, it is suggested that both the second- and fourth-order crystal field terms at the c(6) RE sites are primarily responsible for the displacement of the c and h iron atoms at 47K. | We report an angle-resolved photoemission investigation of optimally-doped Ca$_{0.33}$Na$_{0.67}$Fe$_2$As$_2$. The Fermi surface topology of this compound is similar to that of the well-studied Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ material, except for larger hole pockets resulting from a higher hole concentration per Fe atoms. We find that the quasi-nesting conditions are weakened in this compound as compared to Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$. As with Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ though, we observe nearly isotropic superconducting gaps with Fermi surface-dependent magnitudes. A small variation in the gap size along the momentum direction perpendicular to the surface is found for one of the Fermi surfaces. Our superconducting gap results on all Fermi surface sheets fit simultaneously very well to a global gap function derived from a strong coupling approach, which contains only 2 global parameters. | eng_Latn | 27,865 |
First-principles study on the electronic structure of bismuth transition-metal oxides | The electronic structure, magnetic and electric properties, and lattice stability of multiferroic BiMnO 3 as a typical system in perovskite Bi transition-metal oxides (BiMO 3 ) are studied from first principles. It is demonstrated theoretically for the first time that the orbital ordering within the Mn eg orbitals is actually realized in BiMnO 3 , being consistent with crystallographic data, and plays a crucial role in the appearance of ferromagnetism. Total-energy calculation shows the ferromagnetic state is indeed stabilized. Electrical polarization of BiMnO 3 is also estimated based on the Berry phase theory. Lattice instability to off-centred displacement, which is driven by strong covalent bonding between Bi 6p and O 2p states, is found to be rather common in the BiMO 3 series. | A novel microstrip bandpass filter with four transmission zeros is proposed. Four transmission zeros close to the passband are realized to improve the selectivity for the passband. A sixth- order passband is realized with two shorted stubs and a dual-mode ring resonator. The transmission zeros near the passband can be adjusted conveniently by only changing the characteristic impedances of the coupled lines. For demonstration, a planar bandpass filter (3-dB bandwidth 21.9%) was designed and fabricated. | eng_Latn | 27,866 |
Magnetic Quantum Tunnelling in Faster Relaxation Process in Mn 12 Ac Molecular Magnets | The field-tuned ac susceptibility of Mn12Ac single crystal has been measured as functions of temperature and frequency. Two relaxation processes appear in our measurement. One is related to the magnetic quantum tunnelling of a collective spin S = 12 by a 61 K magnetic barrier and it has been well studied, while the other is faster than the former and its mechanism is unclear. We find that the relaxation time for the faster process shows the minima at H = 0 and H = 3.4 kOe, indicating that the quantum tunnelling also takes place in this process while the resonant fields are different from what we have known before. | Abstract A layer of random defects in the simple cubic Ising model with nearest neighbor ferromagnetic interactions of strength J is considered. Using the real space renormalization group method we calculate defect free energy in the whole temperature range. Specifically, we analyze: the layer of diluted defects, the layer of spin-glass type defects, and the layer of mixed defects. The free energy is strongly dependent on the value of couplings between the defect and the bulk. | eng_Latn | 27,867 |
Valence Bond Order and Antiferromagnetism in Silicene - ab initio Results | Silicene and Graphene are similar and have $\pi$-$\pi^*$ bands. However band width in silicene is only a third of graphene. It results in a substantial increase in the ratio of Hubbard U to band width W, U/W $\sim$ 0.5 in graphene to $\sim 1$ in silicene. This enhancement, 2 dimensionality and phenomenology suggest a Mott insulator based ground state for silicene (G. Baskaran, arXiv:1309.2242). We lend support to the above proposal by showing, in an ab-initio calculation, that unlike graphene, silicene has two instabilities: i) a valence bond (Kekule) dimerization and ii) a weak two sublattice antiferromagnetic order. Presence of these instabilities, in the absence of fermi surface nesting, point to Mott localization, \textit{within the frame work of ab-initio scheme}. Substrate dependent structural reconstructions seen experimentally in silicene are interpreted as generalized Kekule bond order. | Background ::: Sentinel lymph node biopsy (SLNB) is a highly accurate method for staging the axilla in early breast cancer. Superparamagnetic iron oxide mapping agents have been explored to overcome the disadvantages of the standard SLNB technique, which uses a radioisotope tracer with or without blue dye. One such agent, Sienna+, was shown to be non-inferior to the standard technique for SLNB in a number of studies. The SentimagIC trial was designed to establish the non-inferiority of a new formulation of this magnetic tracer, Magtrace (formerly SiennaXP). | eng_Latn | 27,868 |
[Circumstances of Parkinson's disease diagnosis]. | Parkinson's disease is one of the most frequent neurodegenerative diseases. The usual characteristic signs combine the classical triad, rest tremor, bradykinesia and rigidity. The diagnosis is usually easy after several years, especially when the levodopa responsiveness is established, and most of the differential diagnosis can then be ruled out. However, the diagnosis of Parkinson's disease is not confirmed at autopsy in 25% of cases. The errors are much more frequent at disease onset since the clinical presentation may be insidious and may comprise non-motor signs such as pain, vegetative, sensory or neuropsychological signs. In the future, early recognition of the disease will become more and more important with the development of neuroprotective therapeutic strategies. | Abstract A simple pseudopotential (PP) model developed by us earlier was used here to study lattice dynamics and lattice statics of copper. Comparison of the accuracy attainable in different model calculations of the off-symmetry phonon frequencies was made, and the PP model appeared to be at least as accurate as the embedded atom method (EAM). We suggest that calculation of further lattice properties is necessary to evaluate any microscopic model properly. As an example we give a brief review of the PP model application in the lattice dynamics of alloys including the calculation of frequency shifts in different palladium-based alloys. | eng_Latn | 27,869 |
THz-driven ultrafast spin-lattice scattering | We use single-cycle THz fields to excite magnetization dynamics in thin-film ferromagnets with different lattice structure: crystalline Fe and amorphous CoFeB. We observe Landau-Lifshitz-torque magnetization dynamics of comparable magnitude in both systems, but only the amorphous sample shows ultrafast demagnetization caused by the spinlattice depolarization of the THz-induced ultrafast spin current. | This work describes a method for providing robustness to errors from a binary symmetric channel for the SPIHT image compression. The source rate and channel rate are jointly optimized by a stream of fixed-size channel packets. Punctured turbo codes are used for the channel coding, providing stronger error protection than previously available codes. We use a subset of the puncturing patterns that are well chosen and that leads to the best source rate. The rate allocation scheme presented obtains all necessary information from the SPIHT encoder, and does not require image decompression. | eng_Latn | 27,870 |
Instability of polarons and bipolarons in conducting polymers at various 3-d ordering types | Abstract Interchain electron hopping t ⊥ in conducting polymers with the small confinement parameter γ leads to the antiferromagnetic (AB) 3-d ordering of the dimerization pattern only at 2 t 2 γ > γΔ 2 (2Δ being the Peierls gap), otherwise the ferromagnetic (AA) one occurs. Polarons ( Ps , υ = 1) and bipolarons ( BPs , υ = 2) stability areas: t ⊥ / Δ t c (υ,γ) are found in the phase plane “t ⊥ vs γ” with critical t c being larger in the AB phase and for BPs. At the AA-AB transition interface, “deconfinement” of kink-solitons is possible. Photogeneration of Ps and BPs may proceed via metastable free states separated by the self-trapping barriers (STBs) which are also different in AA and AB (in the latter STBs exist even in 2-d systems) and are lower for BPs. | The new 3D turntable can measure the loudspeaker′s vertical directional characteristic,and any angle of loudspeaker′s frequency response.The loudspeaker′s 3D polar radion measurements are designed and loudspeaker′s balloon model is defined by AES56—2008.According to this standard,3D polar radion measurement is provided.And it compares with the measurement of normal directional measurement. | eng_Latn | 27,871 |
Magnetization dynamics driven by spin-polarized current in nanomagnets | Abstract In this report, micromagnetic simulations of magnetization dynamics driven by spin-polarized currents (SPCs) on magnetic nanopillars of permalloy/Cu/permalloy with different rectangular cross-sections are presented. Complete dynamical stability diagrams from initial parallel and antiparallel states have been computed for 100 ns. The effects of a space-dependent polarization function together with the presence of magnetostatic coupling from the fixed layer and classical Ampere field have been taken into account. | This paper makes a more accurate determination of the depth at which the acceptors created by manganese lie, measures the cross section for trapping of holes in its centers, and obtains additional information on hopping conductivity in Mn-doped InP. In addition, the optical chracteristics of Mn centers and the kinetics of the photocurrent in manganese-doped InP in the case of characteristic excitation are studied. It is shown that the cross section for trapping of a hole by a filled acceptor level of manganese is equal to ca 3.10/sup -14/ cm/sup 2/. | eng_Latn | 27,872 |
Structures and magnetic properties of metal cubes | Abstract Structures and magnetic properties of copper(II), nickel(II) and manganese(II) cubes are presented. In the cubes, four metal ions are assembled into the cubes by tridentate Schiff base ligands. Magnetic succeptibility measurements revealed the copper and nickel cubes have high-spin ground state, while the manganese cube has a S =0 spin ground state. | Microstructural studies and X-ray diffraction combined with pole figure characterizations have been carried out on the melt-grown YBa2Cu3O7-x and GdBa2Cu3O7-x samples. The crystallographic orientation of the domains in melt-grown samples are highlighted based on the above studies. | eng_Latn | 27,873 |
Preparation of Porous ZrO2-Al2O3 Composite Ceramic with High Strength and Good Corrosion-Resistance | In order to develop porous ceramics with high strength and corrosion resistance as the support for the preparation of asymmetric ceramic membranes, porous ZrO2-Al2O3 composite is designed and fabricated by adding Zr(OH)4.as sintering aid. The content of Zr(OH)4, the sintering temperature and the bending strength before and after corrosion of the composite are discussed. The results shows that 10wt% ZrO2-10wt% Zr(OH)4 -80wt%Al2O3 composite bar fabricated by cold press with the porosity of 32% can be fabricated in 1550°C for 4 h. The bending strength of the composite is 111.2MPa. After corrosion, the quality lose and the bending strength lose is no more than 1%. The tubular composite is suit for the preparation of micro-filtration membrane. | Based on density functional calculations, we present a detailed theoretical study of the electronic structure and the magnetic properties of the quasi-one dimensional chain cuprate Li_2ZrCuO_4 (Li_2CuZrO_4). For the relevant ratio of the next-nearest neighbor exchange J_2 to the nearest neighbor exchange J_1 we find alpha = -J_2/J_1 = 0.22\pm0.02 which is very close to the critical point at 1/4. Owing this vicinity to a ferromagnetic-helical critical point, we study in detail the influence of structural peculiarities such as the reported Li disorder and the non-planar chain geometry on the magnetic interactions combining the results of LDA based tight-binding models with LDA+U derived exchange parameters. Our investigation is complemented by an exact diagonalization study of a multi-band Hubbard model for finite clusters predicting a strong temperature dependence of the optical conductivity for Li_2ZrCuO_4. | eng_Latn | 27,874 |
Vacancies in thermal equilibrium and ferromagnetism near the Curie temperature | Abstract In several refractory body-centred cubic metals (α-Fe, V, Nb, Ta) the binding energy of positrons (e+) trapped in vacancies is too small to permit accurate determinations of the enthalpy of formation of monovacancies, HF1v, by high-temperature positron annihilation. Owing to their larger mass, trapped positive muons (m+) and π-mesons (π+) are much more firmly bound to vacancies. It is argued that the lattice steering (channelling or blocking) of their charged decay products (e+ or m+) allows us to obtain accurate HF1V values of the refractory bcc metals. In ferromagnets with high Curie temperatures TC, such as α-Fe, Co, and FeCo alloys, HF1V may also be deduced from muon spin rotation (m+SR) measurements. However, in Fe and Co this approach is limited by the strong sensitivity of the spontaneous magnetization against temperature fluctuations near TC. The reduction of this sensitivity in the so-called asymptotic critical regime by applying sufficiently strong external magnetic fields is investigat... | We report an angle-resolved photoemission investigation of optimally-doped Ca$_{0.33}$Na$_{0.67}$Fe$_2$As$_2$. The Fermi surface topology of this compound is similar to that of the well-studied Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ material, except for larger hole pockets resulting from a higher hole concentration per Fe atoms. We find that the quasi-nesting conditions are weakened in this compound as compared to Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$. As with Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ though, we observe nearly isotropic superconducting gaps with Fermi surface-dependent magnitudes. A small variation in the gap size along the momentum direction perpendicular to the surface is found for one of the Fermi surfaces. Our superconducting gap results on all Fermi surface sheets fit simultaneously very well to a global gap function derived from a strong coupling approach, which contains only 2 global parameters. | eng_Latn | 27,875 |
Magnetic phase diagram of ordered (Fe1-xMnx)Pt alloys | Abstract The magnetic structure and magnetic phase transitions of ordered (Fe 1- x Mn x )Pt alloys were investigated by neutron diffraction in the temperature range 4.2–900 K. A complete magnetic phase diagram is drawn up, where the regions for different magnetic states and the character of transitions between them are shown. The theoretical analysis of the magnetic phase stability is given. | In Fig 3E, the labels on the graph in the lower panel are swapped. The solid line should be labeled Pe sup and the dashed line should be labeled PeΔaprA sup. Please see the corrected Fig 3 here. | eng_Latn | 27,876 |
Dipolar order under fast magic-angle spinning | Abstract The thermodynamics of systems of nuclear spins coupled by dipolar interactions is investigated under fast magic-angle spinning. It is shown experimentally and theoretically that, although the two-spin quasi-invariant – the dipolar Hamiltonian – is averaged out, a dipolar quasi-invariant exists, resulting from `three-spin' terms in the series development of the effective Hamiltonian which rules the spin system evolution. The related nuclear spin order, here called the pseudo-dipolar order, is studied as well as its saturation by the sample rotation and its thermal mixing with the Zeeman order by weak radio-frequency irradiation. | In this paper, we extend our previous template analysis of a self-exciting Faraday disc dynamo with a linear series motor to the case of a nonlinear series motor. This introduces two additional nonlinear symmetry-breaking terms into the governing dynamo equations. We investigate the consequences for the identification of a possible template on which the unstable periodic orbits (UPOs) lie. By computing Gauss linking numbers between pairs of UPOs, we show that their values are not incompatible with those for a template for the Lorenz attractor for its classic parameter values. | eng_Latn | 27,877 |
Driven Vortex States and Relaxation in Single Crystal $YBa_2Cu_4O_8$ | The vortex response to various ac-drives has been studied in high quality $YBa_2Cu_4O_8$ single crystals. ::: Well within the vortex solid phase a re-entrant resistive state has been observed that is characterized by long relaxation times. Pulse current response and IV characteristics reveal that in this state the driven vortex system relaxes in a way to increase t he effective pinning force. A phenomenological model accounts for the observed features, in particular the clock-wise hysteresis of the IV-curves and the increase of the apparent critical current with applied current amplitude. | Abstract Recently we proposed the hypercubic smearing (HYP) that improves the flavor symmetry of staggered fermions by an order of magnitude with only minimal distortions at small distances. We describe a new algorithm to simulate dynamical HYP fermions based on the standard pure gauge overrelaxation and heatbath updates. The algorithm has been used to simulate four and two flavors of staggered fermions. Unlike standard dynamical simulation techniques, this algorithm does not loose efficiency at small quark masses. | eng_Latn | 27,878 |
Critical dynamics of a uniaxial and dipolar ferromagnet | We study the critical dynamics of three-dimensional ferromagnets with uniaxial anisotropy by taking into account exchange and dipole-dipole interaction. The dynamic spin correlation functions and the transport coefficients are calculated within a mode coupling theory. It is found that the crossover scenario is determined by the subtle interplay between three length scales: the correlation length, the dipolar and uniaxial wave vector. We compare our theoretical findings with hyperfine interaction experiments on Gd and find quantitative agreement. This analysis allows us to identify the universality class for Gd. It also turns out that the µSR relaxation rate can be best fitted if it is assumed that muons occupy octahedral interstitials sites within the Gd lattice. | In this paper a rigorous mathematical analysis of a synchronous machine with solid cylindrical rotor is presented. The analysis embodies a departure from the usual method of considering machine performance by means of circuit theory, and presents an attack from the point of view of field-distribution theory. Such an analysis is desirable, for it provides a definite means of considering the effect of eddy currents in the solid iron rotor. | eng_Latn | 27,879 |
New Results on Minimizing AC Power Losses in a Fast Cycling 2 T Superferric Dipole With a Cold Yoke | New results from the investigation of 2 T superferric model dipoles operating at 4 T/s, 1 Hz are presented. The works are performed within the R&D program on the design of the SIS100 synchrotron at GSI in Darmstadt. One of the main research goals is minimization of overall AC power losses in the magnet at 4 K level. Different modifications of the dipole were proposed and tested experimentally. By the present time, the losses are reduced to about 17 W/m of the magnet length, while the reference Nuclotron dipole produces about 38 W/m in the same operating mode. Essential design details of the model magnets are described and further R&D steps are outlined | Abstract In extension of an earlier note 1) we present some observations of different electric and magnetic switching phenomena in thin polycrystalline EuS film junctions. A possible explanation for qualitatively different nonllinearities of the current transport behavior in spite of very similar preparation conditions of the samples, is a narrow-band energetic structure with the Fermi level lying within such a band or between. | eng_Latn | 27,880 |
Effect of magnetic field dependent viscosity and rotation on ferroconvection saturating a porous medium in the presence of dust particles | This paper deals with the theoretical investigation of the combined effect of magnetic field dependent (MFD) viscosity and rotation on ferroconvection saturating a porous medium in the presence of dust particles subjected to a transverse uniform magnetic field. For a flat fluid layer contained between two free boundaries, an exact solution is obtained. A linear stability analysis has been carried out to study the onset of ferroconvection. The cases of stationary convection and oscillatory modes have been discussed. In this paper, an attempt is also made to obtain the sufficient conditions for the non-existence of overstability. | The spin-orbit scattering of 4sp and 5sp impurities in a Mg host is investigated theoretically by self-consistent local-density-functional theory. The calculated spin-orbit scattering cross sections σ SO agree with the available experimental results for low valent impurities. For higher valent impurities we predict a p resonance behavior. For Cu and Ag impurities our results point to errors of density-functional theory in estimating the d contribution to σ SO . In total a consistent interpretation of the trends is given | eng_Latn | 27,881 |
Entropy driven phase transition in itinerant antiferromagnetic monolayers | Based on Monte Carlo calculations, the magnetic ordering in itinerant antiferromagnetic monolayers with geometric frustration has been analyzed. For description of the itinerant magnetism exchange interactions beyond the Heisenberg model such as the biquadratic exchange and the four-spin exchange interaction have been taken into account. We demonstrate that the higher-order exchange interactions remove the structural degeneracy and lead to configurational phase transitions at finite temperatures. A new, entropy driven structural phase transition in $\mathrm{V}∕\mathrm{Ag}(111)$ is predicted theoretically. | We observe magnetic domain structures of MgO/CoFeB with a perpendicular magnetic easy axis under an electric field. The domain structure shows a maze pattern with electric-field dependent isotropic period. The analysis of the period indicates a major role of the electric-field modulation of interfacial magnetic anisotropy for the observation and possible contribution from electric-field modulation of the exchange stiffness constant. | eng_Latn | 27,882 |
Surface Energy of Deformation and Polarization | It will be observed that the internal energy density of polarization and deformation, WL, contains the linear term, b ij o P j,i , in the polarization gradient. The analogous term linear in the strain, say c ij o S ij , is omitted as it is of no consequence. It leads to a homogeneous stress which, in a bounded body with a free surface, can be removed by a homogeneous strain which, in turn, can be regarded as the reference configuration. The situation is otherwise for the term linear in the polarization gradient. Although this, too, produces a homogeneous field, it is a field of E ij rather than T ij . The removal of n i E ij to free a surface results, as is illustrated in Section 8, in a polarization and strain which decay exponentially into the interior of the body. | Abstract Applying the self-consistent solitonic approach [1] to the extended Peierls-Hubbard model on odd rings, the interplay of el-el interactions U, V , various off-diagonal interactions, and external dimerization for the dimerization amplitude is studied by exact diagonalizations in the adiabatic limit. The applicability of an effective spin-Peierls Hamiltonian in the intermediate correlation regime U ~ 3t typical for conjugated polymers and an approximate analytical solution based on the Bethe-ansatz solution for the spin velocity and the continuum model solution for the spin-Peierls problem are discussed. | eng_Latn | 27,883 |
Magnetoresistance behavior of submicron Ni80Fe20 wires | We report the evolution of the magnetoresistance (MR) and magnetization behavior of Ni80Fe20 wire arrays as the width (w) is reduced from 200 to 0.3 μm. At around 1.5 μm width, the hysteretic behavior seen in continuous films shows the near reversible behavior characteristic of spin rotation processes. At low field (H Ms), the linear MR response to the in-plane perpendicular hard axis field suggests a bulklike transverse MR effect. | Abstract Vickers Microhardness has been found to be a new and effective analytical tool for the determination of the transition temperatures in ferroic compounds (ferroelectric and/or ferroelastic) | eng_Latn | 27,884 |
Cubic fields, bicritical crossover, the spherical and van der Waals limits | A cubic field coupling to s mod s mod 2, in n-component spin models induces a bicritical crossover from n-isotropic to Ising-like (m=1) critical behaviour for 1<n< infinity , but to classical behaviour in the limit n to infinity . The mechanism for this is explained and related to the van der Waals or infinite-range crossover. By following the analysis of Nelson and Domany (1976), the bicritical scaling function for the parallel susceptibility in d dimensions is obtained correct to order epsilon =4-d and for general (m,n) in a form correctly reproducing all limits; the effective exponent, gamma eff, is examined numerically in various regimes. | We examine the influence of Ni impurity in cuprates on the distribution of hole carriers by performing numerically exact diagonalization calculations for a model consisting of $\text{Cu}\text{ }3d$, $\text{Ni}\text{ }3d$, and $\text{O}\text{ }2p$ orbitals. Using realistic parameters for the system, we find that a hole is predominantly bound to $\text{O}\text{ }2p$ orbitals around the Ni impurity forming the Zhang-Rice doublet. This imposes strong restrictions on modeling Ni-substituted cuprates. We propose a resonant inelastic x-ray scattering experiment for $\text{Ni}\text{ }K$ edge to confirm hole binding around the Ni impurity. | eng_Latn | 27,885 |
Effect of Ti and Co on the Microstructure and Mechanical Property of Reduced Activation 9Cr3W Steel | The feasibility of replacing high activation element Co by low activation element Ti in reduced activated 9Cr3W steel was investigated in this paper.JMatPro phase diagram calculations were used as a theoretical guidance for preparing and heat treatment of experimental steels.The microstructure and mechanical properties of experimental steels were investigated by OM and SEM observation,tensile and creep tests.The results show that Ti and Co both can improve the creep properties of base steel 9Cr3W.The 5 ferrite caused by Ti addition can be resolved into the matrix by choosing proper heat treatment parameters.1%Co in reduced activation 9Cr3W steel can be replaced by 0.03%Ti. | Results are presented of Mossbauer analyses of [57Fe/Cr]12/MgO (100) superlattices. A combined approach was used, based on model calculations and a method of reconstructing the density distribution function P(Hhf) of the hyperfine fields. This procedure allowed us to systematically subtract the subspectra from the different neighborhood configurations of the resonant 57Fe atom. A detailed structural model was obtained for the Fe-Cr transition region from a “pure” Fe layer to a “pure” Cr layer. A deflection of the magnetic moment of the Fe atoms from the plane of the superlattice layers was identified in the interface of the Fe and Cr layers. The specific magnetic structure of the interface regions with different angular orientations of the magnetic moments of the Fe atoms relative to the plane of the layers (between 0 and 90°) is attributed to the coexistence of strong antiferromagnetic interaction between Fe and Cr atoms and an incommensurate spin density wave in the Cr layers. | eng_Latn | 27,886 |
Critical Behavior of the Uniaxially Anisotropic Spin Glass ZnMn | Critical behaviors of the nonlinear susceptibility in spin glasses have been extensively studied by various experiments and numerical calculations. It has been suggested from both experimental (1,2) and theoretical (3) points of view that the anisotropy in real systems plays an important role for the presence of spin-glass transition and the scaling behavior in the nonlinear susceptibility. Recently, we have studied the uniaxially anisotropic spin-glass ZnMn (4,5) over a wide range of the Mn impurity concentration. Since in ZnMn it is possible to control the ratio of the anisotropy to the variance of the random exchange interaction (D/J) by changing the Mn concentration, systematic study for the effect of the uniaxial anisotropy D on the spin-glass critical behavior could be done in this system. | Abstract The calculated angular dependence of the ion scattering surface yield for incidence near the [101] axis of Au(110) is investigated as a function of first layer relaxation. A reversal of the asymmetry of the angular dependence is observed for both large contractions and large expansions. This reversal results from shadowing in the ion flux distribution near atoms along the [101] row. | eng_Latn | 27,887 |
Synthesis,characterization and magnetism of copper(II)-lan-thanide(III) heterobimetalic complexes with N,N’-oxamidobis-(benzoato) cuprate (II) | Seven new μ-oxamido copper(Ⅱ)-lanthanide(Ⅲ)hetero-bitnetalic complexes described by the fonnula Cu(obbz)Ln-(Ph-phen)2NO3(Ln=La,Nd,Eu,Gd,Tb,Ho,Er),where obbz denotes the oxamidobis(benzoato)and Ph-phen represents 5-phenyl-1,10-phenanthroline,have been synthesized and characterized by the elemental analyses,spectro-scopic(IR,UV,ESR)studies,magnetic moments(at room temperature)and molar conductivity measurement.The temperature dependence of the magnetic susceptibility of Cu(obbz)Gd(Ph-phen)2NO3 complex has been measured over the range 4.2-300 K.The least-squares fit of the experimental susceptibilities based on the spin Hamiltonian operator,H=-2JS1 S2,yielded J=+1.28 cm-1,a weak ferromagnetic coupling.A plausible mechanism for a ferromagnetic coupling between Gd(Ⅲ)-Cu(Ⅱ)is discussed in terms of spin-polarization. | Ba-Y-Cu-O superconducting tapes were fabricated by the reaction between Cu substrate and mixture of BaCO3 and Y2O3 powders. Two layers of different compounds were formed on the Cu substrate after the reaction. The outer layer consisted of Ba2Y1Cu3O9-y superconducting compound and the inner layer was identified as Cu2O. Superconducting transition temperatures of 93 K (onset) and 40 K (offset) for the tapes were obtained. | eng_Latn | 27,888 |
A Study on Azo Copper Complex Reactive Dyes | The synthesis methods of azo copper complex reactive dyes were studied, especiallycontaining the ethyl hydrogen sulfategroups. The result showed, keeping pH in 5～6, the ethyl hydrogen sulfateno changed obviously although the temperature over 100℃ for 10 hours. | We have constructed dichromatic matrices of property coefficients for all 1601 Aizu species. This involves 122 non-magnetic Aizu species and extends the work to the 773 species of phase transitions from disordered magnetic prototypic (parent) phases and the 616 species from ordered magnetic prototypic phases. In addition to coefficients describing the non-magnetic effects we have included the coefficients of pyromagnetic, magnetoelectric, piezomagnetic effects, and magnetic susceptibility. All components of these property tensors are displayed in 13 by 13 matrices; non-zero components of the prototypic phase are given in black and the spontaneous coefficients, that are non-zero in the ferroic phase and zero in the prototypic phase, are given in red. | kor_Hang | 27,889 |
Low-energy magnetic fluctuations in U(Ru1-xRhx)2Si2(x⩽0.02) | Abstract Inelastic neutron scattering experiments were performed on U ( Ru 1 - x Rh x ) 2 Si 2 with x = 0 and 0.02 in order to investigate the variations of the antiferromagnetic (AF) fluctuations with doping Rh. We have found that the energy of the magnetic excitation observed at Q = ( 1 , 0 , 0 ) in the hidden order (HO) phase markedly decreases from ∼ 2.6 meV ( x = 0 ) to ∼ 0 ( x = 0.02 ) with increasing x . In addition, the staggered susceptibility χ Q estimated from the inelastic peak develops in the HO phase at x = 0.02 , while it is suppressed at x = 0 . These results indicate that the AF fluctuation in the HO phase is significantly enhanced with doping Rh. | We theoretically propose a method to identify $\ifmmode\pm\else\textpm\fi{}s$-wave order parameter in recently discovered Fe-pnictide superconductors. Our idea uses the Riedel anomaly in ac-Josephson current through a $\text{SI}(\ifmmode\pm\else\textpm\fi{}\text{S})$ (single-band $s$-wave superconductor/insulator/$\ifmmode\pm\else\textpm\fi{}s$-wave two-band superconductor) junction. We show that the Riedel peak effect leads to vanishing ac-Josephson current at some values of biased voltage. This phenomenon does not occur in the case when the $\ifmmode\pm\else\textpm\fi{}s$-wave superconductor is replaced by a conventional $s$-wave one so that the observation of this vanishing Josephson current would be a clear signature of $\ifmmode\pm\else\textpm\fi{}s$-wave pairing state in Fe-pnictide superconductors. | eng_Latn | 27,890 |
Improved permanent magnet designed for fast superconducting bearing | (57) Abstract: providing a high-temperature superconducting bearing comprising a permanent magnet rotor is levitated by high temperature superconductor structure. Rotor is preferably provided with a plurality of substantially concentric permanent magnet ring coupled to the permanent magnet ring structure with the cross section and rectangular cross-section triangular. Alternating polarity magnet structure and unidirectional polar magnet structure both can be used in this bearing. | Structural, elastic, electronic and Fermi surface studies of AuTe2 have been carried out by means of first principles calculations based on density functional theory. The calculated ground state properties agree well with the experiment. Fermi surface and elastic constants are predicted for the first time and from the calculated elastic constants we find the compound to be mechanically stable satisfying the stability criteria of monoclinic structure. In addition, we also find the c-axis to be more compressible than the other two which is also speculated from the present work. The metallic behaviour of this compound is confirmed from the electronic band structure calculation as we find the bands to cross the Fermi level (EF). In addition, we also observe a FS topology change under pressure which is also explained in the present work. | eng_Latn | 27,891 |
Mineral sulphide oxidation by moderately thermophilic acidophilic bacteria | Mineral sulphide dissolution during autotrophic growth of moderate thermophiles and the limitation of pyrite and chalcopyrite oxidation by acidity and temperature respectively are described. | Abstract We report results of 57Fe Mossbauer measurements on the magnetically concentrated amorphous Fe90Zr10 alloy which give the first evidence of a microscopic origin for the low temperature magnetization anomaly at Tf = 35 K. This is shown by an anomalous increase in the average magnetic hyperfine field B hf (T) below Tf, similar to that observed in crystalline and amorphous re-entrant spin-glass alloys in the concentration range near the percolation threshold. | eng_Latn | 27,892 |
An x-ray emission and density functional theory study of the electronic structure of Zn1- xMnxS | Mn 3d electronic states in the dilute magnetic semiconductor Zn1−x Mnx S (x = 0.1–0.3) are studied using soft x-ray emission (XES) measurements and density functional theory (DFT). Mn L2,3 emission spectra of Zn1−x Mnx S (x = 0.1–0.3) suggest that the Mn impurities do not form clusters in the host ZnS lattice, in agreement with previous models. A shift in the position of a Mn L3 XES feature suggests a change in the nature of the hybridization between the Mn 3d3/2 and S 3p states as a function of x. Our DFT calculations reproduce the weak interatomic exchange interaction, as well as the strong intra-atomic exchange splitting that is expected from observations of Zeeman splitting in such materials. | Abstract A layer of random defects in the simple cubic Ising model with nearest neighbor ferromagnetic interactions of strength J is considered. Using the real space renormalization group method we calculate defect free energy in the whole temperature range. Specifically, we analyze: the layer of diluted defects, the layer of spin-glass type defects, and the layer of mixed defects. The free energy is strongly dependent on the value of couplings between the defect and the bulk. | eng_Latn | 27,893 |
Self-Assembled Cu(II) Cluster from Aerobic Oxidation of Cu(I)Br with Tris(triazolyl)methanol | Abstract Treatment of tris(4-benzyl-1,2,3-triazolyl)methanol (Htbtm) with Cu I Br in refluxed CH 2 Cl 2 under aerobic conditions afforded the hexanuclear Cu II complexes with the formula Cu 6 (µ 3 -O⋅⋅⋅H⋅⋅⋅O-µ 3 )(µ -tbtm-к 3 - O , N 3 , N 3 ' ) 3 (µ-Br) 6 . The crystal structure reveals two Cu 3 (µ-Br) 3 (µ 3 -O) units linked by three deprotonated tbtm ligands and a proton. Magnetic studies of the hexanuclear Cu II cluster show a strong overall antiferromagnetic behavior with a dominant coupling interaction between Cu II ⋅⋅⋅Cu II ions of different Cu 3 (µBr) 3 (µ 3 -O) units. | Based on density functional calculations, we present a detailed theoretical study of the electronic structure and the magnetic properties of the quasi-one dimensional chain cuprate Li_2ZrCuO_4 (Li_2CuZrO_4). For the relevant ratio of the next-nearest neighbor exchange J_2 to the nearest neighbor exchange J_1 we find alpha = -J_2/J_1 = 0.22\pm0.02 which is very close to the critical point at 1/4. Owing this vicinity to a ferromagnetic-helical critical point, we study in detail the influence of structural peculiarities such as the reported Li disorder and the non-planar chain geometry on the magnetic interactions combining the results of LDA based tight-binding models with LDA+U derived exchange parameters. Our investigation is complemented by an exact diagonalization study of a multi-band Hubbard model for finite clusters predicting a strong temperature dependence of the optical conductivity for Li_2ZrCuO_4. | eng_Latn | 27,894 |
Influence of Sample Rotation on the Shape of the Free Induction Decay | Sample rotation is commonly used in NMR as one of the methods which improve the effective homogeneity of magnetic fields. The magic angle spinning (MAS), the double rotation (DOR) and the dynamic angle spinning (DAS) can remove line broadening of an NMR spectrum in solids [1, 2]. It is generally assumed that the NMR spectrum of a rotating sample (in the case of isotropic liquids) is simply the orientationally averaged spectum [3]. Our calculations, which are presented below, show that the sample rotation can change the shape of free induction decay (FID) (and consequently NMR line). We discuss this fact because, as we shall show later, it can disturb the absolute evaluation of the measured relaxation time. The shape of the FID can be calculated from the well-known Bloch equation for the transverse component of the magnetization M (without diffusion) under following assumptions [4]: | We point out that aging occurs for the following simple model of fragmentation-coagulation inspired by Pitman's coalescent random forests. For every $n\in \N$, we consider a uniform random tree with $n$ vertices, and at each step, depending on the outcome of an independent fair coin tossing, either we remove one edge chosen uniformly at random amongst the remaining edges, or we replace one edge chosen uniformly at random amongst the edges which have been removed previously. The process that records the sizes of the tree-components evolves by fragmentation and coagulation. It exhibits aging in the sense that when it is observed after $k$ steps in the regime $k\sim tn+s\sqrt n$ with $t>0$ fixed, it seems to reach a statistical equilibrium as $n\to\infty$; but different values of $t$ yield distinct pseudo-stationary distributions. The approach owes much to the construction by Aldous and Pitman of the standard additive coalescent via Poissonian cuts on the skeleton of a Continuum Random Tree. | eng_Latn | 27,895 |
박막 테이프캐스팅과 동시소성에 의한 연료극 지지형 SOFC 단전지 제조 | An anode-supported SOFC single cell having 5 ㎛ thin electrolyte was fabricated cost-effectively by tape casting, laminating, and co-firing of anode (NiO-YSZ), cathode (LSM-YSZ), and electrolyte (YSZ) components. The optimal slurry compositions of the green tapes for SOFC components were determined by an analysis of the mean diameter, the slurry viscosity, the tensile strength/strain of the green tapes, and their green microstructures. The single cells with a dense electrolyte and porous electrodes could be co-fired successfully at 1325~1350℃ by controlling the contents of pore former and the ratio of coarse YSZ and fine YSZ in the anode and the cathode. The single cell co-fired at 1350℃ showed 100.2 ㎽㎝?² of maximum power density at 800℃ but it was impossible to apply it to operate at low temperature because of low performance and high ASR, which were attributed to formation of the secondary phases in the cathode and the interface between the electrolyte and the cathode. | We report a detailed investigation of GdO$_{1-x}$F$_{x}$FeAs (x = 0, 0.07 and 0.14) samples by means of high-field/high-frequency electron spin resonance (HF-ESR) together with measurements of thermodynamic and transport properties. The parent GdOFeAs compound exhibits Fe long-range magnetic order below 128 K, whereas both doped samples do not show such order and are superconducting with T$_c$ = 20 K (x = 0.07) and T$_c$ = 45 K (x = 0.14). The Gd$^{3+}$ HF-ESR reveals an appreciable exchange coupling between Gd and Fe moments, through which the static magnetic order is clearly seen in the parent compound. Owing to this coupling, HF-ESR can probe sensitively the evolution of the magnetism in the FeAs planes upon F doping. It is found that in both superconducting samples, where the Fe long-range order is absent, there are short-range, static on the ESR time scale magnetic correlations between Fe spins. Their occurrence on a large doping scale may be indicative of the ground states' coexistence. | kor_Hang | 27,896 |
Exact Solutions on the Ground States of Ising Models in Magnetic Fields with Frustration on a Diamond Hierarchical Lattice | Magnetization processes of Ising models with frustration on diamond hierarchical lattices, which contain vertices with high coordination numbers, are exactly obtained at zero temperature. In antiferromagnetic systems, the magnetization cannot saturate under finite magnetic fields owing to the competition between the antiferromagnetic and Zeeman interactions and the intrinsic long-range nature of hierarchical lattices. For the zero-field classical spin-liquid phase found in [Kobayashi et al., J. Phys. Soc. Jpn. 78, 074004 (2009)], an infinitely small applied magnetic field can induce an infinitely small magnetization, despite Ising models that have discrete energy levels. By examining the structure of the partition function, we obtain the ground state spin-configurations and clarify the mechanism of the"gapless like behavior". | In this paper we consider the uniformly resolvable decompositions of the complete graph KvKv, or the complete graph minus a 1-factor as appropriate, into subgraphs such that each resolution class contains only blocks isomorphic to the same graph. We completely determine the spectrum for the case in which all the resolution classes consist of either P3P3s or K3K3s. | eng_Latn | 27,897 |
High-pressure effect on the electronic state in CeNiGe3: pressure-induced superconductivity | We have measured the electrical resistivity of an antiferromagnetic Kondo compound CeNiGe3 under pressure. The Neel temperature initially increases with pressure P up to 3 GPa, then decreases rather steeply with further increasing pressure, and becomes zero at a critical pressure GPa. The A and ρ0 values of the resistivity ρ = ρ0+AT2 in the Fermi liquid relation become maximum around Pc, the A value attaining an extremely large value which is comparable with that in a heavy fermion superconductor CeCu2Si2. Superconductivity is found below 0.48 K in a wide pressure region from 4 to 10 GPa. The upper critical field Hc 2(0) is about 2 T, indicating heavy fermion superconductivity. | We have succeeded in enhancing the current-perpendicular-to-plane (CPP) magnetoresistance of the synthetic spin-valves by controlling the spin-dependent transport through the synthetic ferrimagnetic pinned layer using impurities. The new pinned layer overcomes the disadvantage of the synthetic pinned layer in CPP spin-valves for the magnetoresistance reduction. The experimental results are well described by our calculations based on the two-current theory. The proposed pinned layer, together with our newly developed magnetoresistive ferromagnetic materials, will be quite effective in producing CPP spin-valve sensors for ultrahigh-density data storage systems. | eng_Latn | 27,898 |
Magnetic Resonance Studies of Solid-State Hydrogen and Hydrogen-Related Defects | Hydrogen is a detrimental impurity in many chemical vapor deposited (CVD) materials, particularly those involved in electronic or optical applications. For example, active hydrogen defects have been observed in materials such as silicon, Si, gallium arsenide, GaAs, and diamond, C, thin films. Hydrogen and its related defects can be identified, quantified, and observed using magnetic resonance techniques. These techniques allow a unique quantitative, non-destructive view of hydrogen in the solid-state. Nuclear magnetic resonance (NMR) is used to study hydrogenated defects directly, while electron paramagnetic resonance (EPR) is used to observe hydrogen associated with paramagnetic defects. These observations can enhance our understanding of the effects of hydrogen incorporation on the properties of such materials. | Abstract The spin-phonon spin 1 2 Heisenberg system is found to have the same critical index for the susceptibility as the ideal, rigid lattice ferromagnet. This is in accordance with the criterion for critical index renormalisation expounded by Fisher in terms of the sign of the specific heat index. | eng_Latn | 27,899 |
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