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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/0610127 | Agata Ch\c{e}ci\'nska | A. Checinska, K. Wodkiewicz | Noisy Qutrit Channels | contributed paper: Quantum Probability, Information and Control
Symposium, The University of Nottingham, July 2006, 8 pages, 4 figures | null | null | null | quant-ph | null | We present an analysis of spontaneous emission in a 3-level atom as an
example of a qutrit state under the action of noisy quantum channels. We choose
a 3-level atom with V-configuration to be the qutrit state. Gell-Mann matrices
and a generalized Bloch vector (8-dimensional) are used to describe the qutrit
density operator. Using the time-evolution equations of atomic variables we
find the Kraus representation of spontaneous emission quantum channel (SE
channel). Furthermore, we consider a generalized Werner state of two qutrits
and investigate the separability condition. We give similar analysis of
spontaneous emission for qubit channels. The influence of spontaneous emission
on the separability of Werner states for qutrit and qubit states is compared.
| [
{
"version": "v1",
"created": "Mon, 16 Oct 2006 10:46:06 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Nov 2006 14:51:52 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Checinska",
"A.",
""
],
[
"Wodkiewicz",
"K.",
""
]
]
|
quant-ph/0610128 | Ashot Gevorkyan S | Ashot S. Gevorkyan, Alexander V. Bogdanov, Gunnar Nyman | Regular and Chaotic Quantum Dynamic in Atom-Diatom Reactive Collisions | 12 pages, 5 figures | null | null | null | quant-ph | null | A new micro-irreversible 3D theory of quantum multichannel scattering in the
three-body system is developed. The quantum approach is constructed on the
generating trajectory tubes which allow taking into account influence of
classical non-integrability on the dynamical quantum system. It was shown that
when the volume of classical chaos in phase space is larger than quantum sell
in the main object of quantum system the wavefunction generates chaos (quantum
chaos). The probability of quantum transitions is constructed for this case. On
the example of collinear collision of Li+(FH) -> (LiF)+H system is carried out
the numerical calculation and was shown that in the system is generated quantum
(wave) chaos.
| [
{
"version": "v1",
"created": "Mon, 16 Oct 2006 11:07:01 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Nov 2006 09:36:18 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Gevorkyan",
"Ashot S.",
""
],
[
"Bogdanov",
"Alexander V.",
""
],
[
"Nyman",
"Gunnar",
""
]
]
|
quant-ph/0610129 | K. Ch. Chatzisavvas | K.D. Sen, C.P. Panos, K.Ch. Chatzisavvas, and Ch.C. Moustakidis | Net Fisher information measure versus ionization potential and dipole
polarizability in atoms | 16 pages, 6 figures | null | 10.1016/j.physleta.2006.12.044 | null | quant-ph nlin.AO physics.chem-ph | null | The net Fisher information measure, defined as the product of position and
momentum Fisher information measures and derived from the non-relativistic
Hartree-Fock wave functions for atoms with Z=1-102, is found to correlate well
with the inverse of the experimental ionization potential. Strong direct
correlations of the net Fisher information are also reported for the static
dipole polarizability of atoms with Z=1-88. The complexity measure, defined as
the ratio of the net Onicescu information measure and net Fisher information,
exhibits clearly marked regions corresponding to the periodicity of the atomic
shell structure. The reported correlations highlight the need for using the net
information measures in addition to either the position or momentum space
analogues. With reference to the correlation of the experimental properties
considered here, the net Fisher information measure is found to be superior
than the net Shannon information entropy.
| [
{
"version": "v1",
"created": "Mon, 16 Oct 2006 13:28:56 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Sen",
"K. D.",
""
],
[
"Panos",
"C. P.",
""
],
[
"Chatzisavvas",
"K. Ch.",
""
],
[
"Moustakidis",
"Ch. C.",
""
]
]
|
quant-ph/0610130 | Dario Tamascelli | Diego de Falco and Dario Tamascelli | Grover's algorithm on a Feynman computer | null | J. Phys. A: Math. Gen. 37 (2004) 909-930 | 10.1088/0305-4470/37/3/025 | null | quant-ph | null | We present an implementation of Grover's algorithm in the framework of
Feynman's cursor model of a quantum computer. The cursor degrees of freedom act
as a quantum clocking mechanism, and allow Grover's algorithm to be performed
using a single, time-independent Hamiltonian. We examine issues of locality and
resource usage in implementing such a Hamiltonian. In the familiar language of
Heisenberg spin-spin coupling, the clocking mechanism appears as an excitation
of a basically linear chain of spins, with occasional controlled jumps that
allow for motion on a planar graph: in this sense our model implements the idea
of "timing" a quantum algorithm using a continuous-time random walk. In this
context we examine some consequences of the entanglement between the states of
the input/output register and the states of the quantum clock.
| [
{
"version": "v1",
"created": "Mon, 16 Oct 2006 13:59:33 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"de Falco",
"Diego",
""
],
[
"Tamascelli",
"Dario",
""
]
]
|
quant-ph/0610131 | James B. Hartle | James B. Hartle (University of California, Santa Barbara) | Quantum Physics and Human Language | Contribution to the festschrift for G.C. Ghirardi on his 70th
Birthday, minor corrections | J.Phys.A40:3101-3121,2007 | 10.1088/1751-8113/40/12/S13 | null | quant-ph gr-qc | null | Human languages employ constructions that tacitly assume specific properties
of the limited range of phenomena they evolved to describe. These assumed
properties are true features of that limited context, but may not be general or
precise properties of all the physical situations allowed by fundamental
physics. In brief, human languages contain `excess baggage' that must be
qualified, discarded, or otherwise reformed to give a clear account in the
context of fundamental physics of even the everyday phenomena that the
languages evolved to describe. The surest route to clarity is to express the
constructions of human languages in the language of fundamental physical
theory, not the other way around. These ideas are illustrated by an analysis of
the verb `to happen' and the word `reality' in special relativity and the
modern quantum mechanics of closed systems.
| [
{
"version": "v1",
"created": "Mon, 16 Oct 2006 21:12:01 GMT"
},
{
"version": "v2",
"created": "Wed, 15 Nov 2006 23:35:18 GMT"
},
{
"version": "v3",
"created": "Tue, 19 Dec 2006 19:38:57 GMT"
}
]
| 2008-11-26T00:00:00 | [
[
"Hartle",
"James B.",
"",
"University of California, Santa Barbara"
]
]
|
quant-ph/0610132 | Gilad Gour | Gilad Gour | Entanglement of Collaboration | 6 pages, to appear in Phys. Rev. A | Physical Review A 74, 052307 (2006) | 10.1103/PhysRevA.74.052307 | null | quant-ph | null | The entanglement of collaboration (EoC) quantifies the maximum amount of
entanglement, that can be generated between two parties, A and B, given
collaboration with N-2 other parties, when the N parties share a multipartite
(possibly mixed) state and where the collaboration consists of local operations
and classical communication (LOCC) by all parties. The localizable entanglement
(LE) is defined similarly except that A and B do not participate in the effort
to generate bipartite entanglement. We compare between these two operational
definitions and find sufficient conditions for which the EoC is equal to the
LE. In particular, we find that the two are equal whenever they are measured by
the concurrence or by one of its generalizations called the G-concurrence. We
also find a simple expression for the LE in terms of the Jamiolkowski
isomorphism and prove that it is convex.
| [
{
"version": "v1",
"created": "Mon, 16 Oct 2006 22:11:09 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Gour",
"Gilad",
""
]
]
|
quant-ph/0610133 | Fardin Kheirandish | F. Kheirandish and M. Amooshahi | Dissipation in Quantum Mechanics, Scalar and Vector Field Theory | 32 pages | null | null | null | quant-ph | null | A new minimal coupling method is introduced. A general dissipative quantum
system is investigated consistently and systematically. Some coupling functions
describing the interaction between the system and the environment are
introduced. Based on coupling functions, some susceptibility functions are
attributed to the environment explecitly. Transition probabilities relating the
way energy flows from the system to the environment are calculated and the
energy conservation is explecitly examined. This new formalism is generalized
to the dissipative scalar and vector field theories along the ideas developed
for the quantum dissipative systems
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 05:03:18 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Kheirandish",
"F.",
""
],
[
"Amooshahi",
"M.",
""
]
]
|
quant-ph/0610134 | Qin Wang | Qin Wang, Xiang-Bin Wang, Guang-Can Guo | Practical decoy state method in quantum key distribution with heralded
single photon source | 10 pages, 4 Postscript figures | null | 10.1103/PhysRevA.75.012312 | null | quant-ph | null | We propose a practical decoy state method with heralded single photon source
for quantum key distribution (QKD). In the protocol, 3 intensities are used and
one can estimate the fraction of single-photon counts. The final key rate over
transmission distance is simulated under various parameter sets. Due to the
lower dark count than that of a coherent state, it is shown that a 3-intensity
decoy-state QKD with a heralded source can work for a longer distance than that
of a coherent state.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 05:21:18 GMT"
}
]
| 2013-05-29T00:00:00 | [
[
"Wang",
"Qin",
""
],
[
"Wang",
"Xiang-Bin",
""
],
[
"Guo",
"Guang-Can",
""
]
]
|
quant-ph/0610135 | Candadi Sukumar Dr. | D.M.Brink and C.V.Sukumar | Majorana spin-flip transitions in a magnetic trap | 16pages | null | 10.1103/PhysRevA.74.035401 | null | quant-ph | null | Atoms confined in a magnetic trap can escape by making spin-flip Majorana
transitions due to a breakdown of the adiabatic approximation. Several papers
have studied this process for atoms with spin $F = 1/2$ or $F= 1$. The present
paper calculates the escape rate for atoms with spin $F > 1$. This problem has
new features because the perturbation $\Delta T$ which allows atoms to escape
satisfies a selection rule $\Delta F_z = 0, \pm 1, \pm 2$ and multi-step
processes contribute in leading order. When the adiabatic approximation is
satisfied the leading order terms can be summed to yield a simple expression
for the escape rate.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 09:59:37 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Brink",
"D. M.",
""
],
[
"Sukumar",
"C. V.",
""
]
]
|
quant-ph/0610136 | Fam Le Kien | K. P. Nayak, P. N. Melentiev, M. Morinaga, Fam Le Kien, V. I. Balykin,
and K. Hakuta | Optical Nanofibers for Manipulating and Probing Single-Atom Fluorescence | null | null | null | null | quant-ph | null | We demonstrate how optical nanofibers can be used to manipulate and probe
single-atom fluorescence. We show that fluorescence photons from a very small
number of atoms, average atom number of less than 0.1, around the nanofiber can
readily be observed through single-mode optical fiber under resonant laser
irradiation. We show also that optical nanofibers enable us to probe the van
der Waals interaction between atoms and surface with high precision by
observing the fluorescence excitation spectrum.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 10:28:32 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Nayak",
"K. P.",
""
],
[
"Melentiev",
"P. N.",
""
],
[
"Morinaga",
"M.",
""
],
[
"Kien",
"Fam Le",
""
],
[
"Balykin",
"V. I.",
""
],
[
"Hakuta",
"K.",
""
]
]
|
quant-ph/0610137 | Li Yan | Yan Li, Hui Jing and Ming-Sheng Zhan | Simultaneous creations of discrete-variable entangle state and
single-photon-added coherent state | 6 pages, 1 figure | null | null | null | quant-ph | null | The single-photon-added coherent state (SPACS), as an intermediate
classical-to-purely-quantum state, was first realized recently by Zavatta
\emph{$et al.$} (Science 306, 660 (2004)). We show here that the success
probability of their SPACS generation can be enhanced by a simple method which
leads to simultaneous creations of a discrete-variable entangled state and a
SPACS or even a hybrid-variable entangled SPACS in two different channels. The
impacts of the input thermal noise are also analyzed.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 17:14:09 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Li",
"Yan",
""
],
[
"Jing",
"Hui",
""
],
[
"Zhan",
"Ming-Sheng",
""
]
]
|
quant-ph/0610138 | Iulia Ghiu | Iulia Ghiu, Gunnar Bjork | Asymmetric two-output quantum processor in any dimension | 8 pages, 2 eps figures | Rom. Journ. Phys. 53, 725 (2008) | null | null | quant-ph | null | We propose two different implementations of an asymmetric two-output
probabilistic quantum processor, which can implement a restricted set of
one-qubit operations. One of them is constructed by combining asymmetric
telecloning with a quantum gate array. We analyze the efficiency of this
processor by evaluating the fidelities between the desired operation and the
one generated by the processor and show that the two output states are the same
as the ones produced by the optimal universal asymmetric Pauli cloning machine.
The schemes require only local operations and classical communication, they
have the advantage of transmitting the two output states directly to two
spatially separated receivers but they have a success probability of 1/2. We
show further that we can perform the same one-qubit operation with unity
probability at the cost of using nonlocal operations. We finally generalize the
two schemes for D-level systems and find that the local ones are successful
with a probability of 1/D and the nonlocal generalized scheme is always
successful.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 13:20:29 GMT"
}
]
| 2013-11-27T00:00:00 | [
[
"Ghiu",
"Iulia",
""
],
[
"Bjork",
"Gunnar",
""
]
]
|
quant-ph/0610139 | G. Massimo Palma | Angelo Carollo and G. Massimo Palma | Observable geometric phase induced by a cyclically evolving dissipative
process | 6 pages, 1 figure | Laser Physics 16 (N 11), 1595-1600, (2006) | 10.1134/S1054660X06110132 | null | quant-ph | null | In a prevous paper (Phys. Rev. Lett. 96, 150403 (2006)) we have proposed a
new way to generate an observable geometric phase on a quantum system by means
of a completely incoherent phenomenon. The basic idea was to force the ground
state of the system to evolve ciclically by "adiabatically" manipulating the
environment with which it interacts. The specific scheme we have previously
analyzed, consisting of a multilevel atom interacting with a broad-band
squeezed vacuum bosonic bath whose squeezing parameters are smoothly changed in
time along a closed loop, is here solved in a more direct way. This new
solution emphasizes how the geometric phase on the ground state of the system
is indeed due to a purely incoherent dynamics
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 14:56:54 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Carollo",
"Angelo",
""
],
[
"Palma",
"G. Massimo",
""
]
]
|
quant-ph/0610140 | Matteo Scala | M. Scala, B. Militello, A. Messina, J. Piilo, S. Maniscalco | Microscopic derivation of the Jaynes-Cummings model with cavity losses | 9 pages, 3 figures New version with minor correction Accepted for
publication on Physical Review A | Phys. Rev. A 75, 013811 (2007) | 10.1103/PhysRevA.75.013811 | null | quant-ph | null | In this paper we provide a microscopic derivation of the master equation for
the Jaynes-Cummings model with cavity losses. We single out both the
differences with the phenomenological master equation used in the literature
and the approximations under which the phenomenological model correctly
describes the dynamics of the atom-cavity system. Some examples wherein the
phenomenological and the microscopic master equations give rise to different
predictions are discussed in detail.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 15:38:07 GMT"
},
{
"version": "v2",
"created": "Wed, 6 Dec 2006 10:04:49 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Scala",
"M.",
""
],
[
"Militello",
"B.",
""
],
[
"Messina",
"A.",
""
],
[
"Piilo",
"J.",
""
],
[
"Maniscalco",
"S.",
""
]
]
|
quant-ph/0610141 | Andrey Leksin | V. A. Averchenko, A. P. Alodjants, S. M. Arakelian, S. N. Bagayev, E.
A. Vinogradov, V. S. Egorov, A. I. Stolyarov, I. A. Chekhonin | High-temperature Bose-Einstein condensation of polaritons: realization
under the intracavity laser pumping of matter condition | 9 pages, PDF only | Kvantovaya Elektronika (Quantum Elactronics), V.36 (2006)
pp.532-538 | null | null | quant-ph | null | A quantum model of Bose-Einstein condensation based on processes involving
polaritons excited in an intracavity absorbing cell with resonance atoms, which
is manifested in the spectral characteristics of the system, is considered. It
is shown that the spectral 'condensation' appears which is directly related to
the degeneracy of a weakly interacting gas of polaritons resulting in
quasi-condensation at room temperature. The possibility of obtaining polariton
condensation as a new phase state by using the confinement of polaritons in an
atomic optical harmonic trap is discussed.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 16:04:58 GMT"
},
{
"version": "v2",
"created": "Sat, 4 Nov 2006 14:02:37 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Averchenko",
"V. A.",
""
],
[
"Alodjants",
"A. P.",
""
],
[
"Arakelian",
"S. M.",
""
],
[
"Bagayev",
"S. N.",
""
],
[
"Vinogradov",
"E. A.",
""
],
[
"Egorov",
"V. S.",
""
],
[
"Stolyarov",
"A. I.",
""
],
[
"Chekhonin",
"I. A.",
""
]
]
|
quant-ph/0610142 | Giulio Chiribella | G. Chiribella, G. M. D'Ariano, and P. Perinotti | Applications of the group SU(1,1) for quantum computation and tomography | 11 pages, no figures | Laser Physics, 2006, Vol. 16, No. 11, pp. 1572-1581 | 10.1134/S1054660X06110119 | null | quant-ph | null | This paper collects miscellaneous results about the group SU(1,1) that are
helpful in applications in quantum optics. Moreover, we derive two new results,
the first is about the approximability of SU(1,1) elements by a finite set of
elementary gates, and the second is about the regularization of group
identities for tomographic purposes.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 16:43:38 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Chiribella",
"G.",
""
],
[
"D'Ariano",
"G. M.",
""
],
[
"Perinotti",
"P.",
""
]
]
|
quant-ph/0610143 | Li Yan | Yan Li, Hui Jing, and Ming-Sheng Zhan | Scheme for conditional generation of photon-added coherent state and
optical entangled $W$ state | 8 pages, 3 figures | null | null | null | quant-ph | null | We propose a simple scheme to generate an arbitrary photon-added coherent
state of a travelling optical field by using only a set of degenerate
parametric amplifiers and single-photon detectors. Particularly, when the
single-photon-added coherent state (SPACS) is observed by following, e.g., the
novel technique of Zavatta \emph{$et al.$} (Science 306, 660 (2004)), we also
obtain the generalized optical entangled $W$ state. Finally, a qualitative
analysis of possible losses in our scheme is given.
| [
{
"version": "v1",
"created": "Tue, 17 Oct 2006 16:53:41 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Li",
"Yan",
""
],
[
"Jing",
"Hui",
""
],
[
"Zhan",
"Ming-Sheng",
""
]
]
|
quant-ph/0610144 | Fardin Kheirandish | F. Kheirandish and H. Pahlavani | Driven single-band tight-binding dynamics, mesoscopic quantum circuits
and realization of generalized parafermionic polynomial algebrasDeformed
parafermionic algebra from single-band tight-binding dynamics | 15 pages. to be published in Physica Scripta (2008) | null | null | null | quant-ph | null | The quantum dynamics of a driven single-band tight-binding model with
different boundary conditions is considered. The relation between the
Hamiltonian describing the single-band tight-binding dynamics and the
Hamiltonian of a discrete-charge mesoscopic quantum circuit is elucidated. It
is shown that the former Hamiltonian, with Dirichlet boundary conditions, can
be considered as a realization of the deformed parafermionic polynomial
algebras.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 04:17:14 GMT"
},
{
"version": "v2",
"created": "Sat, 18 Nov 2006 10:30:12 GMT"
},
{
"version": "v3",
"created": "Fri, 24 Nov 2006 07:14:35 GMT"
},
{
"version": "v4",
"created": "Fri, 7 Dec 2007 14:27:08 GMT"
}
]
| 2011-11-09T00:00:00 | [
[
"Kheirandish",
"F.",
""
],
[
"Pahlavani",
"H.",
""
]
]
|
quant-ph/0610145 | Qiang Zhang | Qiang Zhang, Xiao-Hui Bao, Chao-Yang Lu, Xiao-Qi Zhou, Tao Yang, Terry
Rudolph, Jian-Wei Pan | Demonstration of efficient scheme for generation of "Event Ready"
entangled photon pairs from single photon source | 4 pages, 4 figures | Phys. Rev. A 77, 062316 (2008) | 10.1103/PhysRevA.77.062316 | null | quant-ph | null | We present a feasible and efficient scheme, and its proof-of-principle
demonstration, of creating entangled photon pairs in an event-ready way using
only simple linear optical elements and single photons. The quality of
entangled photon pair produced in our experiment is confirmed by a strict
violation of Bell's inequality. This scheme and the associated experimental
techniques present an important step toward linear optics quantum computation.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 05:10:22 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Zhang",
"Qiang",
""
],
[
"Bao",
"Xiao-Hui",
""
],
[
"Lu",
"Chao-Yang",
""
],
[
"Zhou",
"Xiao-Qi",
""
],
[
"Yang",
"Tao",
""
],
[
"Rudolph",
"Terry",
""
],
[
"Pan",
"Jian-Wei",
""
]
]
|
quant-ph/0610146 | Koenraad M. R. Audenaert | Koenraad M.R. Audenaert | A Sharp Fannes-type Inequality for the von Neumann Entropy | 5 pages, 3 figures | J. Phys. A 40, 8127--8136 (2007). | 10.1088/1751-8113/40/28/S18 | null | quant-ph | null | We derive an inequality relating the entropy difference between two quantum
states to their trace norm distance, sharpening a well-known inequality due to
M. Fannes. In our inequality, equality can be attained for every prescribed
value of the trace norm distance.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 13:49:39 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Audenaert",
"Koenraad M. R.",
""
]
]
|
quant-ph/0610147 | Simon Kochen | John Conway and Simon Kochen | On Adler's "Conway-Kochen Twin Argument" | null | null | null | null | quant-ph | null | We respond to Stephen Adler's comments on our paper "The Free Will
Theorem",and add some further observations.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 13:05:27 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Conway",
"John",
""
],
[
"Kochen",
"Simon",
""
]
]
|
quant-ph/0610148 | Yong Zhang | Yong Zhang (Chern Inst. Math., Nankai) | Teleportation, Braid Group and Temperley--Lieb Algebra | 33 pages, 19 figures, latex. The present article is a short version
of the preprint, quant-ph/0601050, which includes details of calculation,
more topics such as topological diagrammatical operations and entanglement
swapping, and calls the Temperley--Lieb category for the collection of all
the Temperley--Lieb algebra with physical operations like local unitary
transformations | J.Phys.A39:11599-11622,2006 | 10.1088/0305-4470/39/37/017 | null | quant-ph hep-th math-ph math.MP | null | We explore algebraic and topological structures underlying the quantum
teleportation phenomena by applying the braid group and Temperley--Lieb
algebra. We realize the braid teleportation configuration, teleportation
swapping and virtual braid representation in the standard description of the
teleportation. We devise diagrammatic rules for quantum circuits involving
maximally entangled states and apply them to three sorts of descriptions of the
teleportation: the transfer operator, quantum measurements and characteristic
equations, and further propose the Temperley--Lieb algebra under local unitary
transformations to be a mathematical structure underlying the teleportation. We
compare our diagrammatical approach with two known recipes to the quantum
information flow: the teleportation topology and strongly compact closed
category, in order to explain our diagrammatic rules to be a natural
diagrammatic language for the teleportation.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 13:40:21 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Zhang",
"Yong",
"",
"Chern Inst. Math., Nankai"
]
]
|
quant-ph/0610149 | Matthew Jones | Jerome Beugnon (LCFIO), Matthew Jones (LCFIO), Jos Dingjan (LCFIO),
Benoit Darqui\'e (LCFIO), Gaetan Messin (LCFIO), Antoine Browaeys (LCFIO),
Philippe Grangier (LCFIO) | Quantum interference between two single photons emitted by independently
trapped atoms | null | Nature 440 (06/04/2006) 779 | 10.1038/nature04628 | null | quant-ph | null | When two indistinguishable single photons are fed into the two input ports of
a beam splitter, the photons will coalesce and leave together from the same
output port. This is a quantum interference effect, which occurs because the
two possible paths where the photons leave in different output ports interfere
destructively. This effect was first observed in parametric downconversion by
Hong, Ou and Mandel, and then with single photons produced one after the other
by the same quantum emitter. With the recent development of quantum
information, a lot of attention has been devoted to this coalescence effect as
a resource for quantum data processing using linear optics techniques. To
ensure the scalability of schemes based on these ideas, it is crucial that
indistinguishable photons are emitted by a collection of synchronized, but
otherwise independent sources. In this paper, we demonstrate the quantum
interference of two single photons emitted by two independently trapped single
atoms, bridging the gap towards the simultaneous emission of many
indistinguishable single photons by different emitters. Our data analysis shows
that the coalescence observed is mostly limited by the wavefront matching of
the light emitted by the two atoms, and to a lesser extent by the motion of
each atom in its own trap.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 14:07:38 GMT"
}
]
| 2016-08-16T00:00:00 | [
[
"Beugnon",
"Jerome",
"",
"LCFIO"
],
[
"Jones",
"Matthew",
"",
"LCFIO"
],
[
"Dingjan",
"Jos",
"",
"LCFIO"
],
[
"Darquié",
"Benoit",
"",
"LCFIO"
],
[
"Messin",
"Gaetan",
"",
"LCFIO"
],
[
"Browaeys",
"Antoine",
"",
"LCFIO"
],
[
"Grangier",
"Philippe",
"",
"LCFIO"
]
]
|
quant-ph/0610150 | Itay Rabinak | Itay Rabinak, Eran Ginossar and Shimon Levit | Atom in a coherently controlled squeezed vacuum | 4 pages, 4 figures | Phys. Rev. A 76 013821 (2007) | 10.1103/PhysRevA.76.013821 | null | quant-ph | null | A broadband squeezed vacuum photon field is characterized by a complex
squeezing function. We show that by controlling the wavelength dependence of
its phase it is possible to change the dynamics of the atomic polarization
interacting with the squeezed vacuum. Such a phase modulation effectively
produces a finite range temporal interaction kernel between the two quadratures
of the atomic polarization yielding the change in the decay rates as well as
the appearance of additional oscillation frequencies. We show that decay rates
slower than the spontaneous decay rate can be achieved even for a squeezed bath
in the classic regime. For linear and quadratic phase modulations the power
spectrum of the scattered light exhibits narrowing of the central peak due to
the modified decay rates. For strong phase modulations side lobes appear
symmetrically around the central peak reflecting additional oscillation
frequencies.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 15:53:02 GMT"
}
]
| 2008-03-11T00:00:00 | [
[
"Rabinak",
"Itay",
""
],
[
"Ginossar",
"Eran",
""
],
[
"Levit",
"Shimon",
""
]
]
|
quant-ph/0610151 | Barbara Kraus | Barbara Kraus, Cyril Branciard, and Renato Renner | Security of quantum key distribution protocols using two-way classical
communication or weak coherent pulses | null | Phys. Rev. A 75, 012316 (2007) | 10.1103/PhysRevA.75.012316 | null | quant-ph | null | We apply the techniques introduced in [Kraus et. al., Phys. Rev. Lett. 95,
080501, 2005] to prove security of quantum key distribution (QKD) schemes using
two-way classical post-processing as well as QKD schemes based on weak coherent
pulses instead of single-photon pulses. As a result, we obtain improved bounds
on the secret-key rate of these schemes.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 15:33:26 GMT"
}
]
| 2011-11-09T00:00:00 | [
[
"Kraus",
"Barbara",
""
],
[
"Branciard",
"Cyril",
""
],
[
"Renner",
"Renato",
""
]
]
|
quant-ph/0610152 | Susan Clark | Susan M. Clark, Kai-Mei C. Fu, Thaddeus D. Ladd, Yoshihisa Yamamoto | Quantum computers based on electron spins controlled by ultra-fast,
off-resonant, single optical pulses | 4 pages, 4 figures, introduction is clarified, the section on
two-qubit gates was expanded and much more detail about gate fidelities is
given, figures were modified, one figure replaced with a figure showing gate
fidelities for relevant parameters | null | 10.1103/PhysRevLett.99.040501 | null | quant-ph | null | We describe a fast quantum computer based on optically controlled electron
spins in charged quantum dots that are coupled to microcavities. This scheme
uses broad-band optical pulses to rotate electron spins and provide the clock
signal to the system. Non-local two-qubit gates are performed by phase shifts
induced by electron spins on laser pulses propagating along a shared waveguide.
Numerical simulations of this scheme demonstrate high-fidelity single-qubit and
two-qubit gates with operation times comparable to the inverse Zeeman
frequency.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 18:57:26 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Oct 2006 21:42:07 GMT"
},
{
"version": "v3",
"created": "Mon, 11 Jun 2007 19:01:21 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Clark",
"Susan M.",
""
],
[
"Fu",
"Kai-Mei C.",
""
],
[
"Ladd",
"Thaddeus D.",
""
],
[
"Yamamoto",
"Yoshihisa",
""
]
]
|
quant-ph/0610153 | Andreas Klappenecker | Salah A. Aly, Andreas Klappenecker, Pradeep Kiran Sarvepalli | Subsystem Codes | 8 pages; 44th Allerton Conference | null | null | null | quant-ph cs.IT math.IT | null | We investigate various aspects of operator quantum error-correcting codes or,
as we prefer to call them, subsystem codes. We give various methods to derive
subsystem codes from classical codes. We give a proof for the existence of
subsystem codes using a counting argument similar to the quantum
Gilbert-Varshamov bound. We derive linear programming bounds and other upper
bounds. We answer the question whether or not there exist
[[n,n-2d+2,r>0,d]]<sub>q</sub> subsystem codes. Finally, we compare stabilizer
and subsystem codes with respect to the required number of syndrome qudits.
| [
{
"version": "v1",
"created": "Wed, 18 Oct 2006 21:19:17 GMT"
}
]
| 2007-07-13T00:00:00 | [
[
"Aly",
"Salah A.",
""
],
[
"Klappenecker",
"Andreas",
""
],
[
"Sarvepalli",
"Pradeep Kiran",
""
]
]
|
quant-ph/0610154 | Thaddeus Ladd Ph.D. | Thaddeus D. Ladd, Peter van Loock, Kae Nemoto, William J. Munro,
Yoshihisa Yamamoto | Hybrid quantum repeater based on dispersive CQED interactions between
matter qubits and bright coherent light | Please consult the published version, where assorted typos are
corrected. It is freely available at http://stacks.iop.org/1367-2630/8/184 | New J. Phys. 8, 164 (2006) | 10.1088/1367-2630/8/9/184 | null | quant-ph | null | We describe a system for long-distance distribution of quantum entanglement,
in which coherent light with large average photon number interacts dispersively
with single, far-detuned atoms or semiconductor impurities in optical cavities.
Entanglement is heralded by homodyne detection using a second bright light
pulse for phase reference. The use of bright pulses leads to a high success
probability for the generation of entanglement, at the cost of a lower initial
fidelity. This fidelity may be boosted by entanglement purification techniques,
implemented with the same physical resources. The need for more purification
steps is well compensated for by the increased probability of success when
compared to heralded entanglement schemes using single photons or weak coherent
pulses with realistic detectors. The principle cause of the lower initial
fidelity is fiber loss; however, spontaneous decay and cavity losses during the
dispersive atom/cavity interactions can also impair performance. We show that
these effects may be minimized for emitter-cavity systems in the weak-coupling
regime as long as the resonant Purcell factor is larger than one, the cavity is
over-coupled, and the optical pulses are sufficiently long. We support this
claim with numerical, semiclassical calculations using parameters for three
realistic systems: optically bright donor-bound impurities such as 19-F:ZnSe
with a moderate-Q microcavity, the optically dim 31-P:Si system with a high-Q
microcavity, and trapped ions in large but very high-Q cavities.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 00:06:22 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Ladd",
"Thaddeus D.",
""
],
[
"van Loock",
"Peter",
""
],
[
"Nemoto",
"Kae",
""
],
[
"Munro",
"William J.",
""
],
[
"Yamamoto",
"Yoshihisa",
""
]
]
|
quant-ph/0610155 | Zhi-Yong Wang | Zhi-Yong Wang, Cai-Dong Xiong, Bing He | Field-theoretical space-time position operator of the Dirac electron | This paper has been withdrawn by the author due to a crucial error in
this paper | null | null | null | quant-ph | null | A field-theoretical space-time position operator can be properly introduced
for the Dirac field, it plays the role of a generalized Noether charge
associated with a local symmetry, and its second-quantized form shows that
quantum fields possess zero-point time, which implies that a zero-point
fluctuation of energy must be accompanied with a zero-point fluctuation of
time, and then in agreement with the time-energy uncertainty principle. In
practice, some possible physical effects owing to zero-point time remain to be
found.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 05:34:03 GMT"
},
{
"version": "v2",
"created": "Tue, 5 Dec 2006 14:36:44 GMT"
},
{
"version": "v3",
"created": "Mon, 6 Aug 2007 12:46:24 GMT"
},
{
"version": "v4",
"created": "Tue, 11 Jan 2011 13:40:07 GMT"
}
]
| 2011-01-12T00:00:00 | [
[
"Wang",
"Zhi-Yong",
""
],
[
"Xiong",
"Cai-Dong",
""
],
[
"He",
"Bing",
""
]
]
|
quant-ph/0610156 | Charles Hill | Charles D. Hill, J. F. Ralph | Weak measurement and rapid state reduction in bipartite quantum systems | 4 pages, 3 figures | null | 10.1088/1367-2630/9/5/151 | null | quant-ph | null | In this paper we consider feedback control algorithms for the rapid
purification of a bipartite state consisting of two qubits, when the observer
has access to only one of the qubits. We show 1) that the algorithm that
maximizes the average purification rate is not the same as that that for a
single qubit, and 2) that it is always possible to construct an algorithm that
generates a deterministic rate of purification for {\em both} qubits. We also
reveal a key difference between projective and continuous measurements with
regard to state-purification.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 10:32:16 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Dec 2006 14:47:38 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Hill",
"Charles D.",
""
],
[
"Ralph",
"J. F.",
""
]
]
|
quant-ph/0610157 | Maarten Van den Nest | M. Van den Nest, W. D\"ur, H. J. Briegel | Classical spin models and the quantum stabilizer formalism | 5 pages | Phys. Rev. Lett. 98, 117207 (2007) | 10.1103/PhysRevLett.98.117207 | null | quant-ph cond-mat.stat-mech | null | We relate a large class of classical spin models, including the inhomogeneous
Ising, Potts, and clock models of q-state spins on arbitrary graphs, to
problems in quantum physics. More precisely, we show how to express partition
functions as inner products between certain quantum stabilizer states and
product states. This connection allows us to use powerful techniques developed
in quantum information theory, such as the stabilizer formalism and classical
simulation techniques, to gain general insights into these models in a unified
way. We recover and generalize several symmetries and high-low temperature
dualities, and we provide an efficient classical evaluation of partition
functions for all interaction graphs with a bounded tree-width.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 15:27:45 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Nest",
"M. Van den",
""
],
[
"Dür",
"W.",
""
],
[
"Briegel",
"H. J.",
""
]
]
|
quant-ph/0610158 | Eyal Buks | Eyal Buks, Eran Arbel-Segev, Stav Zaitsev, Baleegh Abdo and M. P.
Blencowe | Quantum Nondemolition Measurement of Discrete Fock States of a
Nanomechanical Resonator | null | null | null | null | quant-ph cond-mat.mes-hall cond-mat.supr-con | null | We study theoretically a radio frequency superconducting interference device
integrated with both a nanomechanical resonator and an LC one. By applying
adiabatic and rotating wave approximations, we obtain an effective Hamiltonian
that governs the dynamics of the mechanical and LC resonators. Nonlinear terms
in this Hamiltonian can be exploited for performing a quantum nondemolition
measurement of Fock states of the nanomechanical resonator. We address the
feasibility of experimental implementation and show that the nonlinear coupling
can be made sufficiently strong to allow the detection of discrete mechanical
Fock states.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 11:49:22 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Oct 2006 12:12:55 GMT"
},
{
"version": "v3",
"created": "Wed, 25 Oct 2006 08:14:50 GMT"
},
{
"version": "v4",
"created": "Thu, 23 Aug 2007 07:40:28 GMT"
}
]
| 2007-08-23T00:00:00 | [
[
"Buks",
"Eyal",
""
],
[
"Arbel-Segev",
"Eran",
""
],
[
"Zaitsev",
"Stav",
""
],
[
"Abdo",
"Baleegh",
""
],
[
"Blencowe",
"M. P.",
""
]
]
|
quant-ph/0610159 | Sofia Wechsler | Sofia Wechsler | Are superluminal "signals" an acceptable hypothesis? - Difficulties in
building a communication protocol with them | This article is based on very old information. It needs major
modifications | null | null | null | quant-ph | null | The local hidden variable assumption was repeatedly proved unable to explain
results of experiments in which contextuality is involved. Then, the correlated
results of measurements of entangled particles, began to be attributed to a
communication between particles through so-called "signals". These "signals"
need to possess superluminal velocity or move backward in time. No object that
has a rest-mass, not even the photons whose rest mass is zero, behave this way.
Still, as the nature of the presumed "sinals" is not known, people don't reject
the idea, despite the conflict with the theory of relativity. For this reason,
the present article examines the "signals" from another point of view: wherever
runs a communication, there has also to exist a communication protocol. The
article tries to outline a communication protocol between the space-separated,
entangled particles, and comes to a contradiction, making the idea of such a
communication highly doubtable.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 12:57:23 GMT"
},
{
"version": "v2",
"created": "Sat, 11 Nov 2006 18:47:23 GMT"
},
{
"version": "v3",
"created": "Mon, 14 Oct 2019 00:42:57 GMT"
}
]
| 2019-10-15T00:00:00 | [
[
"Wechsler",
"Sofia",
""
]
]
|
quant-ph/0610160 | Stefano Olivares | Stefano Olivares and Matteo G. A. Paris | De-Gaussification by inconclusive photon subtraction | 17 pages, 30 figures | Laser Physics vol. 16, 1533 (2006) | 10.1134/S1054660X06110077 | null | quant-ph | null | We address conditional de-Gaussification of continuous variable states by
inconclusive photon subtraction (IPS) and review in details its application to
bipartite twin-beam state of radiation. The IPS map in the Fock basis has been
derived, as well as its counterpart in the phase-space. Teleportation assisted
by IPS states is analyzed and the corresponding fidelity evaluated as a
function of the involved parameters. Nonlocality of IPS states is investigated
by means of different tests including displaced parity, homodyne detection,
pseudospin, and displaced on/off photodetection. Dissipation and thermal noise
are taken into account, as well as non unit quantum efficiency in the detection
stage. We show that the IPS process, for a suitable choice of the involved
parameters, improves teleportation fidelity and enhances nonlocal properties.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 13:33:06 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Olivares",
"Stefano",
""
],
[
"Paris",
"Matteo G. A.",
""
]
]
|
quant-ph/0610161 | Asa Ericsson | Ingemar Bengtsson, Wojciech Bruzda, Asa Ericsson, Jan-{\AA}ke Larsson,
Wojciech Tadej and Karol Zyczkowski | Mubs and Hadamards of Order Six | 33 pages, 3 figures. References added in v2 | J. Math. Phys. 48, 052106 (2007) | 10.1063/1.2716990 | null | quant-ph | null | We report on a search for mutually unbiased bases (MUBs) in 6 dimensions. We
find only triplets of MUBs, and thus do not come close to the theoretical upper
bound 7. However, we point out that the natural habitat for sets of MUBs is the
set of all complex Hadamard matrices of the given order, and we introduce a
natural notion of distance between bases in Hilbert space. This allows us to
draw a detailed map of where in the landscape the MUB triplets are situated. We
use available tools, such as the theory of the discrete Fourier transform, to
organise our results. Finally we present some evidence for the conjecture that
there exists a four dimensional family of complex Hadamard matrices of order 6.
If this conjecture is true the landscape in which one may search for MUBs is
much larger than previously thought.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 14:38:53 GMT"
},
{
"version": "v2",
"created": "Wed, 28 Feb 2007 16:05:51 GMT"
},
{
"version": "v3",
"created": "Fri, 1 Jun 2007 05:11:29 GMT"
}
]
| 2022-03-16T00:00:00 | [
[
"Bengtsson",
"Ingemar",
""
],
[
"Bruzda",
"Wojciech",
""
],
[
"Ericsson",
"Asa",
""
],
[
"Larsson",
"Jan-Åke",
""
],
[
"Tadej",
"Wojciech",
""
],
[
"Zyczkowski",
"Karol",
""
]
]
|
quant-ph/0610162 | Sergey Bravyi | Sergey Bravyi and Robert Raussendorf | On measurement-based quantum computation with the toric code states | 9 pages, 5 figures | Phys. Rev. A 76, 022304 (2007) | 10.1103/PhysRevA.76.022304 | null | quant-ph | null | We study measurement-based quantum computation (MQC) using as quantum
resource the planar code state on a two-dimensional square lattice (planar
analogue of the toric code). It is shown that MQC with the planar code state
can be efficiently simulated on a classical computer if at each step of MQC the
sets of measured and unmeasured qubits correspond to connected subsets of the
lattice.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 19:03:29 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Bravyi",
"Sergey",
""
],
[
"Raussendorf",
"Robert",
""
]
]
|
quant-ph/0610163 | Yao Cheng | Yao Cheng, Zhongming Wang | Resonant Propagation of Entangled Rhodium Mossbauer Gammas | null | null | null | null | quant-ph physics.atom-ph | null | We report the resonant propagation of the long-lived Mossbauer gamma in the
time-resolved Mossbauer spectroscopy. Recently, three entangled gammas emitted
from the E3 rhodium Mossbauer transition has been proposed to interpret the
extraordinary observations in the previous report. Further observation reported
here is the dynamic beat of these entangled gammas at room temperature and 77K.
Apparent beat anisotropy reveals their long-distance resonant propagation,
which leads to suppressed Doppler shift of entangled photon transport in the
Borrmann channel.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 15:48:08 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Cheng",
"Yao",
""
],
[
"Wang",
"Zhongming",
""
]
]
|
quant-ph/0610164 | Gregory Furman | Gregory B. Furman | Zeroth order quantum coherences and preparation of pseudopure state in
homonuclear dipolar coupling spin systems | 15 pages, 7 figures | null | null | null | quant-ph | null | Dynamics of zeroth order quantum coherences and preparation of the pseudopure
states in homonuclear systems of dipolar coupling spins is closely examined. It
has been shown an extreme important role of the non-diagonal part of zeroth
order coherence in construction of the pseudopure state. Simulations of the
preparation process of pseudopure states with the real molecular structures (a
rectangular (-chloro- -nitrobenzene molecule), a chain (hydroxyapatite
molecule), a ring (benzene molecule), and a double ring (cyclopentane
molecule)) open the way to experimental testing of the obtained results.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 17:16:44 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Furman",
"Gregory B.",
""
]
]
|
quant-ph/0610165 | David Daems | D. Daems | Entanglement-enhanced classical capacity of two-qubit quantum channels
with memory: the exact solution | 5 pages | Phys. Rev. A 76, 012310 (2007) | 10.1103/PhysRevA.76.012310 | null | quant-ph | null | The maximal amount of information which is reliably transmitted over two uses
of general Pauli channels with memory is proven to be achieved by maximally
entangled states beyond some memory threshold. In particular, this proves a
conjecture on the depolarizing channel by Macchiavello and Palma [Phys. Rev. A
{\bf 65}, 050301(R) (2002)]. Below the memory threshold, for arbitrary Pauli
channels, the two-use classical capacity is only achieved by a particular type
of product states.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 18:11:19 GMT"
}
]
| 2011-11-09T00:00:00 | [
[
"Daems",
"D.",
""
]
]
|
quant-ph/0610166 | Lincoln D. Carr | Lincoln D. Carr, D. R. Dounas-Frazer, and Miguel-\'Angel
Garc\'ia-March | Dynamical Realization of Macroscopic Superposition States of Cold Bosons
in a Tilted Double Well | 6 pages, 5 figures, final version, only minor changes from previous
arXiv version | Europhys. Lett., v. 90, p. 10005 (2010) | 10.1209/0295-5075/90/10005 | null | quant-ph cond-mat.other | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present exact expressions for the quantum sloshing of Bose-Einstein
condensates in a tilted two-well potential. Tunneling is suppressed by a small
potential difference between wells, or tilt. However, tunneling resonances
occur for critical values of the tilt when the barrier is high. At resonance,
tunneling times on the order of 10-100 ms are possible. Furthermore, such
tilted resonances lead to a dynamical scheme for creating few-body NOON-like
macroscopic superposition states which are protected by the many body
wavefunction against potential fluctuations.
| [
{
"version": "v1",
"created": "Thu, 19 Oct 2006 22:50:01 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Feb 2010 20:11:56 GMT"
},
{
"version": "v3",
"created": "Wed, 5 May 2010 00:16:40 GMT"
}
]
| 2010-05-06T00:00:00 | [
[
"Carr",
"Lincoln D.",
""
],
[
"Dounas-Frazer",
"D. R.",
""
],
[
"García-March",
"Miguel-Ángel",
""
]
]
|
quant-ph/0610167 | Frank Gaitan | Ran Li, Melique Hoover, and Frank Gaitan | High Fidelity Single-Qubit Gates Using Non-adiabatic Rapid Passage | 16 pages; further discussion added on quantum interferences and sweep
parameter precision | Quantum Information and Computation vol. 7, 594 (2007) | null | null | quant-ph | null | Numerical simulation results are presented which suggest that a class of
non-adiabatic rapid passage sweeps first realized experimentally in 1991 should
be capable of implementing a set of quantum gates that is universal for
one-qubit unitary operations and whose elements operate with error
probabilities per operation P < 10^{-4}. The sweeps are non-composite and
generate controllable quantum interference effects which allow the one-qubit
gates produced to operate non-adiabatically while maintaining high accuracy.
The simulations suggest that the one-qubit gates produced by these sweeps show
promise as possible elements of a fault-tolerant scheme for quantum computing.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 01:50:26 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Mar 2007 18:16:19 GMT"
}
]
| 2007-06-20T00:00:00 | [
[
"Li",
"Ran",
""
],
[
"Hoover",
"Melique",
""
],
[
"Gaitan",
"Frank",
""
]
]
|
quant-ph/0610168 | Zheng-Wei Zhou | Zheng-Wei Zhou, Yong-Jian Han, and Guang-Can Guo | Local Operations in qubit arrays via global but periodic Manipulation | 5 pages, 2 figures, to appear in Phys. Rev. A | Phys. Rev. A 74, 052334 (2006) | 10.1103/PhysRevA.74.052334 | null | quant-ph | null | We provide a scheme for quantum computation in lattice systems via global but
periodic manipulation, in which only effective periodic magnetic fields and
global nearest neighbor interaction are required. All operations in our scheme
are attainable in optical lattice or solid state systems. We also investigate
universal quantum operations and quantum simulation in 2 dimensional lattice.
We find global manipulations are superior in simulating some nontrivial many
body Hamiltonians.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 06:11:34 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Zhou",
"Zheng-Wei",
""
],
[
"Han",
"Yong-Jian",
""
],
[
"Guo",
"Guang-Can",
""
]
]
|
quant-ph/0610169 | Giovanni Manfredi | G. Manfredi, P.-A. Hervieux | Loschmidt echo in a system of interacting electrons | 4 pages, 6 figures, to appear in PRL | null | 10.1103/PhysRevLett.97.190404 | null | quant-ph | null | We study the Loschmidt echo for a system of electrons interacting through
mean-field Coulomb forces. The electron gas is modeled by a self-consistent set
of hydrodynamic equations. It is observed that the quantum fidelity drops
abruptly after a time that is proportional to the logarithm of the perturbation
amplitude. The fidelity drop is related to the breakdown of the symmetry
properties of the wave function.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 08:20:23 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Manfredi",
"G.",
""
],
[
"Hervieux",
"P. -A.",
""
]
]
|
quant-ph/0610170 | Kazuo Fujikawa | Kazuo Fujikawa | Geometric phases for mixed states and decoherence | 23 pages. To be published in Annals of Physics | AnnalsPhys.322:1500-1517,2007 | 10.1016/j.aop.2006.10.003 | null | quant-ph cond-mat.mes-hall hep-th | null | The gauge invariance of geometric phases for mixed states is analyzed by
using the hidden local gauge symmetry which arises from the arbitrariness of
the choice of the basis set defining the coordinates in the functional space.
This approach gives a reformulation of the past results of adiabatic,
non-adiabatic and mixed state geometric phases. The geometric phases are
identified uniquely as the holonomy associated with the hidden local gauge
symmetry which is an exact symmetry of the Schr\"{o}dinger equation. The
purification and its inverse in the description of de-coherent mixed states are
consistent with the hidden local gauge symmetry. A salient feature of the
present formulation is that the total phase and visibility in the mixed state,
which are directly observable in the interference experiment, are manifestly
gauge invariant.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 08:34:57 GMT"
}
]
| 2008-11-26T00:00:00 | [
[
"Fujikawa",
"Kazuo",
""
]
]
|
quant-ph/0610171 | Indranil Chakrabarty ic | Indranil Chakrabarty, Satyabrata Adhikari, B.S. Choudhury | Probabilistic exact deletion and probabilistic no-signalling | 6 pages, Accepted in Physica Scripta | Phys. Scr.74 (2006) 555-557 | 10.1088/0031-8949/74/5/012 | null | quant-ph | null | In this work we show that one cannot use non-local resources for
probabilistic signalling even if one can delete a quantum state with the help
of probabilistic quantum deletion machine. Here we find that probabilistic
quantum deletion machine is not going to help us in identifying two statistical
mixture at remote location. Also we derive the bound on deletion probability
from no-signalling condition.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 08:39:32 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Chakrabarty",
"Indranil",
""
],
[
"Adhikari",
"Satyabrata",
""
],
[
"Choudhury",
"B. S.",
""
]
]
|
quant-ph/0610172 | Alexia Auffeves-Garnier | Alexia Auffeves-Garnier, Christoph Simon, Jean-Michel Gerard and
Jean-Philippe Poizat | Giant Optical Non-linearity induced by a Single Two-Level System
interacting with a Cavity in the Purcell Regime | 40 pages, 16 figures, accepted in Phys. Rev. A | null | 10.1103/PhysRevA.75.053823 | null | quant-ph | null | A two-level system that is coupled to a high-finesse cavity in the Purcell
regime exhibits a giant optical non-linearity due to the saturation of the
two-level system at very low intensities, of the order of one photon per
lifetime. We perform a detailed analysis of this effect, taking into account
the most important practical imperfections. Our conclusion is that an
experimental demonstration of the giant non-linearity should be feasible using
semiconductor micropillar cavities containing a single quantum dot in resonance
with the cavity mode.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 09:20:31 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Apr 2007 14:30:07 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Auffeves-Garnier",
"Alexia",
""
],
[
"Simon",
"Christoph",
""
],
[
"Gerard",
"Jean-Michel",
""
],
[
"Poizat",
"Jean-Philippe",
""
]
]
|
quant-ph/0610173 | A. F. Kracklauer | A. F. Kracklauer | Are quantum `irreality' and `nonlocality' ineluctable? | 5 pages RevTeX | null | null | null | quant-ph | null | The early history of the development of Quantum Mechanics is surveyed to
discern the arguments leading to the introduction of the notions of `irreal'
wave functions and `nonlocal' correlations. It is argued that the assumption
that Quantum Mechanics is `complete', i.e., not just a variant of Statistical
Mechanics, is the feature compelling the introduction of these otherwise
problematic properties. Additionally, a consequence of the error first found by
Jaynes in proofs of Bell's ``theorem'', is illustrated. Finally, speculation on
the practical consequences of recognising that ``entanglement'' is a feature of
all hyperbolic differential equations is proposed.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 10:32:30 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Kracklauer",
"A. F.",
""
]
]
|
quant-ph/0610174 | Lev Vaidman | Lev Vaidman | The Impossibility of the Counterfactual Computation for all Possible
Outcomes | This version includes a better answer to Hosten and Kwiat comment
[quant-ph/0612159] | null | 10.1103/PhysRevLett.98.160403 | null | quant-ph | null | Recent proposal for counterfactual computation [Hosten et al., Nature, 439,
949 (2006)] is analyzed. It is argued that the method does not provide
counterfactual computation for all possible outcomes. The explanation involves
a novel paradoxical feature of pre- and post-selected quantum particles: the
particle can reach a certain location without being on the path that leads to
this location.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 10:43:24 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Dec 2006 22:45:08 GMT"
},
{
"version": "v3",
"created": "Tue, 2 Jan 2007 21:03:05 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Vaidman",
"Lev",
""
]
]
|
quant-ph/0610175 | A. A. Methot | N. Gisin, A.A. Methot and V. Scarani | Pseudo-telepathy: input cardinality and Bell-type inequalities | 12 pages, no figures | International Journal of Quantum Information 5: 525-534, 2007. | null | null | quant-ph | null | Pseudo-telepathy is the most recent form of rejection of locality. Many of
its properties have already been discovered: for instance, the minimal
entanglement, as well as the minimal cardinality of the output sets, have been
characterized. This paper contains two main results. First, we prove that no
bipartite pseudo-telepathy game exists, in which one of the partners receives
only two questions; as a corollary, we show that the minimal "input
cardinality", that is, the minimal number of questions required in a bipartite
pseudo-telepathy game, is 3x3. Second, we study the Bell-type inequality
derived from the pseudo-telepathy game known as the Magic Square game: we
demonstrate that it is a tight inequality for 3 inputs and 4 outputs on each
side and discuss its weak resistance to noise.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 11:37:18 GMT"
}
]
| 2007-10-26T00:00:00 | [
[
"Gisin",
"N.",
""
],
[
"Methot",
"A. A.",
""
],
[
"Scarani",
"V.",
""
]
]
|
quant-ph/0610176 | Eugene Ivanchenko | E. A. Ivanchenko | Three-qubit dynamics of entanglement in magnetic field | 9 pages, 3 figures accepted by Fiz. Niz. Temp., vol. 33, 2007 [Low
Temperature Physics ] | null | null | null | quant-ph | null | A closed system of the equations for the local Bloch vectors and spin
correlation functions is obtained by decomplexification of the Liouville-von
Neumann equation for three magnetic qubits with the exchange interaction, that
takes place in an arbitrary time-dependent external magnetic field. The
numerical comparative analysis of entanglement is carried out depending on
initial conditions and the magnetic field modulation. The present study may be
useful for analysis of interference experiments and in the field of quantum
computing.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 13:41:04 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Ivanchenko",
"E. A.",
""
]
]
|
quant-ph/0610177 | Indranil Chakrabarty ic | C.G.Chakrabarti, Indranil Chakrabarty | Boltzmann-Shannon Entropy: Generalization and Application | 5 pages, Accepted in Mod.Phys.Lett.B | Mod.Phys.Lett.B, Vol.20, No. 23, 1471 (2006) | 10.1142/S0217984906011529 | null | quant-ph | null | The paper deals with the generalization of both Boltzmann entropy and
distribution in the light of most-probable interpretation of statistical
equilibrium. The statistical analysis of the generalized entropy and
distribution leads to some new interesting results of significant physical
importance.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 15:10:28 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Chakrabarti",
"C. G.",
""
],
[
"Chakrabarty",
"Indranil",
""
]
]
|
quant-ph/0610178 | Toshiyuki Shimono | Toshiyuki Shimono | Analysis of the Entanglement Cost and Calculation of the Holevo Capacity | A doctoral dissertation, the University of Tokyo, 112 pages, 65
figure files | null | null | null | quant-ph | null | ``Beam me over,'' Alice: A cricket's quantum journey
This thesis addresses two known quantities in quantum information science:
(1) entanglement cost, and (2) Holevo capacity. These quantities will be
crucial values when teleportation becomes common in daily life, perhaps
centuries from now.
Assume that Alice desires to send a singing Japanese cricket to her friend
Bob in America, and that Alice and Bob already share a quantum entanglement.
First, Alice sends Bob a mass of information bits resulting from the
interaction between the cricket she holds in her hand and half of the
entanglement. Subsequently, Bob receives the information bits and manipulates
the other half of the entanglement, transforming them back into the original
cricket. Examining this situation from an instrumental engineering viewpoint,
quantifying the amount of the quantum entanglement and the number of
information bits is crucial for this transmission. If both values are enough,
Alice could even send herself to Bob's place instead of the tiny cricket.
The topics of this thesis therefore are: (1) the mathematical properties of
the entanglement cost, such as whether it is an additive measure similar to
normal length or weight; and (2) how to calculate the Holevo capacity, an
ultimately achievable limit of the information conveyance capacity of an
information channel, such as of a single photon passing through an optical
fiber or space. These two distinct quantities are magically tied together by
several ``additive or not'' hypotheses, which await mathematical proof.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 15:18:09 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Oct 2006 19:24:14 GMT"
},
{
"version": "v3",
"created": "Wed, 25 Oct 2006 15:48:19 GMT"
}
]
| 2009-09-29T00:00:00 | [
[
"Shimono",
"Toshiyuki",
""
]
]
|
quant-ph/0610179 | Jorge Stephany | D. Mundarain, M. Orszag and J. Stephany | Total Quantum Zeno effect and Intelligent States for a two level system
in a squeezed bath | 5 pages, 3 figures | null | 10.1103/PhysRevA.74.052107 | SB/F/06-339 | quant-ph | null | In this work we show that by frequent measurements of adequately chosen
observables, a complete suppression of the decay in an exponentially decaying
two level system interacting with a squeezed bath is obtained. The observables
for which the effect is observed depend on the the squeezing parameters of the
bath. The initial states which display Total Zeno Effect are intelligent states
of two conjugate observables associated to the electromagnetic fluctuations of
the bath.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 20:37:18 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Mundarain",
"D.",
""
],
[
"Orszag",
"M.",
""
],
[
"Stephany",
"J.",
""
]
]
|
quant-ph/0610180 | Christoph Wildfeuer F. | Christoph F. Wildfeuer, Austin P. Lund, and Jonathan P. Dowling | Strong Violations of Bell-type Inequalities for Path-Entangled Number
States | 6 pages, LaTex; revised version accepted for publication in PRA | Phys. Rev. A 76, 052101 (2007) | 10.1103/PhysRevA.76.052101 | null | quant-ph | null | We show that nonlocal correlation experiments on the two spatially separated
modes of a maximally path-entangled number state may be performed and lead to a
violation of a Clauser-Horne Bell inequality for any finite photon number N. We
present also an analytical expression for the two-mode Wigner function of a
maximally path-entangled number state and investigate a
Clauser-Horne-Shimony-Holt Bell inequality for such states. We test other
Bell-type inequalities. Some are violated by a constant amount for any N.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 21:01:06 GMT"
},
{
"version": "v2",
"created": "Tue, 31 Oct 2006 14:39:40 GMT"
},
{
"version": "v3",
"created": "Thu, 4 Jan 2007 18:39:32 GMT"
},
{
"version": "v4",
"created": "Mon, 24 Sep 2007 01:56:09 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Wildfeuer",
"Christoph F.",
""
],
[
"Lund",
"Austin P.",
""
],
[
"Dowling",
"Jonathan P.",
""
]
]
|
quant-ph/0610181 | Francisco Diego Mazzitelli | F.D. Mazzitelli, D.A.R. Dalvit, and F.C. Lombardo | Exact zero-point interaction energy between cylinders | 20 pages, 7 figures | New J.Phys.8:240,2006 | 10.1088/1367-2630/8/10/240 | null | quant-ph hep-th | null | We calculate the exact Casimir interaction energy between two perfectly
conducting, very long, eccentric cylindrical shells using a mode summation
technique. Several limiting cases of the exact formula for the Casimir energy
corresponding to this configuration are studied both analytically and
numerically. These include concentric cylinders, cylinder-plane, and eccentric
cylinders, for small and large separations between the surfaces. For small
separations we recover the proximity approximation, while for large separations
we find a weak logarithmic decay of the Casimir interaction energy, typical of
cylindrical geometries.
| [
{
"version": "v1",
"created": "Fri, 20 Oct 2006 21:05:15 GMT"
}
]
| 2011-07-19T00:00:00 | [
[
"Mazzitelli",
"F. D.",
""
],
[
"Dalvit",
"D. A. R.",
""
],
[
"Lombardo",
"F. C.",
""
]
]
|
quant-ph/0610182 | Xiao-Hui Bao | Xiao-Hui Bao, Teng-Yun Chen, Qiang Zhang, Jian Yang, Han Zhang, Tao
Yang, and Jian-Wei Pan | Optical Nondestructive Controlled-NOT Gate without Using Entangled
Photons | 5 pages, 3 figures, Slight changes have been made, Journal-ref added | Phys. Rev. Lett. 98 170502 (2007) | 10.1103/PhysRevLett.98.170502 | null | quant-ph | null | We present and experimentally demonstrate a novel optical nondestructive
controlled-NOT gate without using entangled ancilla. With much fewer
measurements compared with quantum process tomography, we get a good estimation
of the gate fidelity. The result shows a great improvement compared with
previous experiments. Moreover, we also show that quantum parallelism is
achieved in our gate and the performance of the gate can not be reproduced by
local operations and classical communications.
| [
{
"version": "v1",
"created": "Sat, 21 Oct 2006 05:49:14 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Dec 2006 13:44:04 GMT"
},
{
"version": "v3",
"created": "Tue, 8 May 2007 01:46:25 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Bao",
"Xiao-Hui",
""
],
[
"Chen",
"Teng-Yun",
""
],
[
"Zhang",
"Qiang",
""
],
[
"Yang",
"Jian",
""
],
[
"Zhang",
"Han",
""
],
[
"Yang",
"Tao",
""
],
[
"Pan",
"Jian-Wei",
""
]
]
|
quant-ph/0610183 | Ramazan Sever | Sameer M. Ikhdair and Ramazan Sever | Exact Solution of the Klein-Gordon Equation for the PT-Symmetric
Generalized Woods-Saxon Potential by the Nikiforov-Uvarov Method | 29 pages, 8 figures | null | 10.1002/andp.200610232 | Annalen der physik 16, 218(2007) | quant-ph | null | The one-dimensional Klein-Gordon (KG) equation has been solved for the
PT-symmetric generalized Woods-Saxon (WS) potential. The Nikiforov-Uvarov(NU}
method which is based on solving the second-order linear differential equations
by reduction to a generalized equation of hypergeometric type is used to obtain
exact energy eigenvalues and corresponding eigenfunctions. We have also
investigated the positive and negative exact bound states of the s-states for
different types of complex generalized WS potentials.
| [
{
"version": "v1",
"created": "Sat, 21 Oct 2006 07:38:14 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Ikhdair",
"Sameer M.",
""
],
[
"Sever",
"Ramazan",
""
]
]
|
quant-ph/0610184 | Sandor Varro | Sandor Varro | Irreducible decomposition of Gaussian distributions and the spectrum of
black-body radiation | 29 pages | Physica Scripta, Vol. 75, pp 160-169 (2007) | 10.1088/0031-8949/75/2/008 | null | quant-ph | null | It is shown that the energy of a mode of a classical chaotic field, following
the continuous exponential distribution as a classical random variable, can be
uniquely decomposed into a sum of its fractional part and of its integer part.
The integer part is a discrete random variable (we call it Planck variable)
whose distribution is just the Bose distribution yielding the Planck law of
black-body radiation. The fractional part is the dark part (we call is dark
variable) with a continuous distribution, which is, of course, not observed in
the experiments. It is proved that the Bose distribution is infinitely
divisible, and the irreducible decomposition of it is given. The Planck
variable can be decomposed into an infinite sum of independent binary random
variables representing the binary photons (more accurately photo-molecules or
photo-multiplets) of energies 2^s*h*nu with s=0,1,2... . These binary photons
follow the Fermi statistics. Consequently, the black-body radiation can be
viewed as a mixture of statistically and thermodynamically independent fermion
gases consisting of binary photons. The binary photons give a natural tool for
the dyadic expansion of arbitrary (but not coherent) ordinary photon
excitations. It is shown that the binary photons have wave-particle
fluctuations of fermions. These fluctuations combine to give the wave-particle
fluctuations of the original bosonic photons expressed by the Einstein
fluctuation formula.
| [
{
"version": "v1",
"created": "Sat, 21 Oct 2006 08:24:24 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Varro",
"Sandor",
""
]
]
|
quant-ph/0610185 | Leonid A. Krivitsky | G. Brida, M.V. Chekhova, M. Genovese, L.A. Krivitsky, E. Predazzi | Go and return propagation of biphotons in fiber and polarization
entanglement | 6 pages, 4 figures | Journal of Physics A, 40 7985-7995 (2007) | null | null | quant-ph | null | Propagation of entangled photons in optical fiber is one of the fundamental
issues for realizing quantum communication protocols. When entanglement in
polarization is considered, arises the problem of compensating for the fiber
effect on photons polarization. In this paper we demonstrate an effective
solution where a Faraday mirror allows to cancel undesired effects of
polarization drift in fiber. This technique is applied to a protocol for
generating Bell states by a narrow temporal selection of the second-order
intensity correlation function.
| [
{
"version": "v1",
"created": "Sat, 21 Oct 2006 19:14:50 GMT"
}
]
| 2007-06-28T00:00:00 | [
[
"Brida",
"G.",
""
],
[
"Chekhova",
"M. V.",
""
],
[
"Genovese",
"M.",
""
],
[
"Krivitsky",
"L. A.",
""
],
[
"Predazzi",
"E.",
""
]
]
|
quant-ph/0610186 | Mahmoud Abdel-Aty | Mahmoud Abdel-Aty | Sudden death and long-living of entanglement in an ion-trap laser | 10 pages 4 figures | null | null | null | quant-ph | null | he dynamical properties of quantum entanglement in a time-dependent
three-level-trapped ion interacting with a laser field are studied in terms of
the reduced-density linear entropy considering two specific initial states of
the field. Allowing the instantaneous position of the center-of-mass motion of
the ion to be explicitly time-dependent, it is shown that either sudden death
of entanglement or survivability of quantum entanglement can be obtained with a
specific choice of the initial state parameters. The difference in evolution
picture corresponding to the multi-quanta processes is discussed.
| [
{
"version": "v1",
"created": "Sun, 22 Oct 2006 08:39:44 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Abdel-Aty",
"Mahmoud",
""
]
]
|
quant-ph/0610187 | Marek Czachor | Diederik Aerts, Marek Czachor | Notes on Geometric-Algebra Quantum-Like Algorithms | Preliminary version of notes | null | null | null | quant-ph | null | In these notes we present preliminary results on quantum-like algorithms
where tensor product is replaced by geometric product. Such algorithms possess
the essential properties typical of quantum computation (entanglement,
parallelism) but employ additional algebraic structures typical of geometric
algebra -- structures absent in standard quantum computation. As a test we
reformulate in Geometric Algebra terms the Deutsch-Jozsa problem.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 15:15:55 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Aerts",
"Diederik",
""
],
[
"Czachor",
"Marek",
""
]
]
|
quant-ph/0610188 | Shang-Bin Li | Shang-Bin Li | Generation of maximally entangled mixed states of two atoms via
on-resonance asymmetric atom-cavity couplings | 5 pages, 5 figures | Phys. Rev. A 75, 054304 (2007) | 10.1103/PhysRevA.75.054304 | null | quant-ph | null | A scheme for generating the maximally entangled mixed state of two atoms
on-resonance asymmetrically coupled to a single mode optical cavity field is
presented. The part frontier of both maximally entangled mixed states and
maximal Bell violating mixed states can be approximately reached by the
evolving reduced density matrix of two atoms if the ratio of coupling strengths
of two atoms is appropriately controlled. It is also shown that exchange
symmetry of global maximal concurrence is broken if and only if coupling
strength ratio lies between $\frac{\sqrt{3}}{3}$ and $\sqrt{3}$ for the case of
one-particle excitation and asymmetric coupling, while this partial
symmetry-breaking can not be verified by detecting maximal Bell violation.
| [
{
"version": "v1",
"created": "Sun, 22 Oct 2006 16:27:07 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Li",
"Shang-Bin",
""
]
]
|
quant-ph/0610189 | Denes Petz | Denes Petz | Complementarity in quantum systems | 17 pages | Rep. Math. Phys. 59(2007), 209-224. | 10.1016/S0034-4877(07)00010-9 | null | quant-ph math-ph math.MP | null | Reduction of a state of a quantum system to a subsystem gives partial quantum
information about the true state of the total system. Two subalgebras A1 and A2
of B(H) are called complementary if the traceless subspaces of A1 and A2 are
orthogonal (with respect to the Hilbert-Schmidt inner product). When both
subalgebras are maximal Abelian, then the concept reduces to complementary
observables or mutually unbiased bases. In the paper several characterizations
of complementary subalgebras are given in the general case and several examples
are presented. For a 4-level quantum system, the structure of complementary
subalgebras can be described very well, the Cartan decomposition of unitaries
plays a role. It turns out that a measurement corresponding to the Bell basis
is complementary to any local measurement of the two-qubit-system.
| [
{
"version": "v1",
"created": "Sun, 22 Oct 2006 20:14:26 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Petz",
"Denes",
""
]
]
|
quant-ph/0610190 | Mark Everitt | M. J. Everitt | Recovery of classical chaotic-like behaviour in a quantum three-body
problem | 6 pages, 6 figures | Phys. Rev. E 75, 036217 (2007) | 10.1103/PhysRevE.75.036217 | null | quant-ph nlin.CD | null | Recovering trajectories of quantum systems whose classical counterparts
display chaotic behavior has been a subject that has received a lot of interest
over the last decade. However, most of these studies have focused on driven and
dissipative systems. The relevance and impact of chaoticlike phenomena to
quantum systems has been highlighted in recent studies which have shown that
quantum chaos is significant in some aspects of quantum computation and
information processing. In this paper we study a three-body system comprising
of identical particles arranged so that the system's classical trajectories
exhibit Hamiltonian chaos. Here we show that it is possible to recover very
nearly classical-like, conservative, chaotic trajectories from such a system
through an unravelling of the master equation. First, this is done through
continuous measurement of the position of each system. Second, and perhaps
somewhat surprisingly, we demonstrate that we still obtain a very good match
between the classical and quantum dynamics by weakly measuring the position of
only one of the oscillators.
| [
{
"version": "v1",
"created": "Sun, 22 Oct 2006 23:55:39 GMT"
},
{
"version": "v2",
"created": "Tue, 27 Mar 2007 08:57:34 GMT"
}
]
| 2007-07-12T00:00:00 | [
[
"Everitt",
"M. J.",
""
]
]
|
quant-ph/0610191 | Hongchen Fu Prof. | H.C.Fu, Hui Dong, X.F.Liu, C.P.Sun | Indirect control with quantum accessor (I): coherent control of
multi-level system via qubit chain | 9 pages, 3 figures. To appear in Phys.Rev.A | null | 10.1103/PhysRevA.75.052317 | null | quant-ph | null | Indirect controllability of an arbitrary finite dimensional quantum system
(N-dimensional qudit) through a quantum accessor is investigated. Here, The
qudit is coupled to a quantum accessor which is modeled as a fully controllable
spin chain with nearest neighbor (anisotropic) XY-coupling. The complete
controllability of such indirect control system is investigated in detail. The
general approach is applied to the indirect controllability of two and three
dimensional quantum systems. For two and three dimensional systems, a simpler
indirect control scheme is also presented.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 01:00:47 GMT"
},
{
"version": "v2",
"created": "Mon, 30 Oct 2006 00:32:14 GMT"
},
{
"version": "v3",
"created": "Fri, 23 Mar 2007 11:00:38 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Fu",
"H. C.",
""
],
[
"Dong",
"Hui",
""
],
[
"Liu",
"X. F.",
""
],
[
"Sun",
"C. P.",
""
]
]
|
quant-ph/0610192 | Jan Govaerts | Joseph Ben Geloun (1), Jan Govaerts (1,2) and M. Norbert Hounkonnou
(1) ((1) International Chair in Mathematical Physics and Applications
(ICMPA-UNESCO), Cotonou, Rep. Benin, (2) School of Physics, The University of
New South Wales, Sydney, Australia) | (p,q)-Deformations and (p,q)-Vector Coherent States of the
Jaynes-Cummings Model in the Rotating Wave Approximation | 1+25 pages, no figures | null | 10.1063/1.2710651 | ICMPA-MPA/2006/20, CP3-06-13 | quant-ph | null | Classes of (p,q)-deformations of the Jaynes-Cummings model in the rotating
wave approximation are considered. Diagonalization of the Hamiltonian is
performed exactly, leading to useful spectral decompositions of a series of
relevant operators. The latter include ladder operators acting between adjacent
energy eigenstates within two separate infinite discrete towers, except for a
singleton state. These ladder operators allow for the construction of
(p,q)-deformed vector coherent states. Using (p,q)-arithmetics, explicit and
exact solutions to the associated moment problem are displayed, providing new
classes of coherent states for such models. Finally, in the limit of decoupled
spin sectors, our analysis translates into (p,q)-deformations of the
supersymmetric harmonic oscillator, such that the two supersymmetric sectors
get intertwined through the action of the ladder operators as well as in the
associated coherent states.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 05:08:00 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Geloun",
"Joseph Ben",
""
],
[
"Govaerts",
"Jan",
""
],
[
"Hounkonnou",
"M. Norbert",
""
]
]
|
quant-ph/0610193 | Mitsuru Hamada | Mitsuru Hamada | Conjugate Codes and Applications to Cryptography | 7 pages, no fugure. To appear in Tamagawa University Research Review | Tamagawa University Research Review, No. 12, pp. 19--25, 2006 | null | null | quant-ph | null | A conjugate code pair is defined as a pair of linear codes such that one
contains the dual of the other. The conjugate code pair represents the
essential structure of the corresponding Calderbank-Shor-Steane (CSS) quantum
code. It is argued that conjugate code pairs are applicable to quantum
cryptography in order to motivate studies on conjugate code pairs.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 15:42:02 GMT"
}
]
| 2009-01-21T00:00:00 | [
[
"Hamada",
"Mitsuru",
""
]
]
|
quant-ph/0610194 | Mitsuru Hamada | Mitsuru Hamada | Concatenated Conjugate Codes | Submitted to IEEE Trans. Information Theory (Aug. 2006). Ver.2: an
obvious tiny error corrected (rate is k/n, not k) | null | null | null | quant-ph | null | A conjugate code pair is defined as a pair of linear codes either of which
contains the dual of the other. A conjugate code pair represents the essential
structure of the corresponding Calderbank-Shor-Steane (CSS) quantum code. It is
known that conjugate code pairs are applicable to (quantum) cryptography. We
give a construction method for efficiently decodable conjugate code pairs.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 09:10:56 GMT"
},
{
"version": "v2",
"created": "Tue, 31 Oct 2006 18:17:11 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Hamada",
"Mitsuru",
""
]
]
|
quant-ph/0610195 | Mitsuru Hamada | Mitsuru Hamada | Concatenated Quantum Codes Constructible in Polynomial Time: Efficient
Decoding and Error Correction | 16 pages, 3 figures. Ver.4: Title changed. Ver.3: Due to a request of
the AE of the journal, the present version has become a combination of
(thoroughly revised) quant-ph/0610194 and the former quant-ph/0610195.
Problem formulations of polynomial complexity are strictly followed. An
erroneous instance of a lower bound on minimum distance was removed | IEEE Trans. on Information Theory, vol. 54, no. 12, pp.
5689--5704, 2008 | 10.1109/TIT.2008.2006416 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A method for concatenating quantum error-correcting codes is presented. The
method is applicable to a wide class of quantum error-correcting codes known as
Calderbank-Shor-Steane (CSS) codes. As a result, codes that achieve a high rate
in the Shannon theoretic sense and that are decodable in polynomial time are
presented. The rate is the highest among those known to be achievable by CSS
codes. Moreover, the best known lower bound on the greatest minimum distance of
codes constructible in polynomial time is improved for a wide range.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 09:06:59 GMT"
},
{
"version": "v2",
"created": "Tue, 31 Oct 2006 18:11:48 GMT"
},
{
"version": "v3",
"created": "Thu, 3 Jul 2008 15:12:29 GMT"
},
{
"version": "v4",
"created": "Tue, 19 Aug 2008 13:02:31 GMT"
}
]
| 2016-11-17T00:00:00 | [
[
"Hamada",
"Mitsuru",
""
]
]
|
quant-ph/0610196 | Francesco Buscemi Dr | Francesco Buscemi and Massimiliano F. Sacchi | Information-Disturbance Tradeoff in Quantum State Discrimination | 5 pages, 2 (low-quality) figures. Eq. (20) corrected. Final published
version | Phys. Rev. A 74, 052320 (2006) | 10.1103/PhysRevA.74.052320 | null | quant-ph | null | When discriminating between two pure quantum states, there exists a
quantitative tradeoff between the information retrieved by the measurement and
the disturbance caused on the unknown state. We derive the optimal tradeoff and
provide the corresponding quantum measurement. Such an optimal measurement
smoothly interpolates between the two limiting cases of maximal information
extraction and no measurement at all.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 08:44:31 GMT"
},
{
"version": "v2",
"created": "Wed, 15 Nov 2006 00:52:36 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Buscemi",
"Francesco",
""
],
[
"Sacchi",
"Massimiliano F.",
""
]
]
|
quant-ph/0610197 | Alessandro Villar | K. N. Cassemiro, A. S. Villar, P. Valente, M. Martinelli, and P.
Nussenzveig | Experimental observation of three-color optical quantum correlations | 3 pages, 3 figures | null | 10.1364/OL.32.000695 | null | quant-ph | null | Quantum correlations between bright pump, signal, and idler beams produced by
an optical parametric oscillator, all with different frequencies, are
experimentally demonstrated. We show that the degree of entanglement between
signal and idler fields is improved by using information of pump fluctuations.
This is the first observation of three-color optical quantum correlations.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 19:21:56 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Cassemiro",
"K. N.",
""
],
[
"Villar",
"A. S.",
""
],
[
"Valente",
"P.",
""
],
[
"Martinelli",
"M.",
""
],
[
"Nussenzveig",
"P.",
""
]
]
|
quant-ph/0610198 | Philippe Jacquet PhD | W. O. Amrein and Philippe A. Jacquet | Time delay for one-dimensional quantum systems with steplike potentials | 48 pages, 1 figure | Phys.Rev.A75:022106,2007 | 10.1103/PhysRevA.75.022106 | null | quant-ph math-ph math.MP | null | This paper concerns time-dependent scattering theory and in particular the
concept of time delay for a class of one-dimensional anisotropic quantum
systems. These systems are described by a Schr\"{o}dinger Hamiltonian $H =
-\Delta + V$ with a potential $V(x)$ converging to different limits $V_{\ell}$
and $V_{r}$ as $x \to -\infty$ and $x \to +\infty$ respectively. Due to the
anisotropy they exhibit a two-channel structure. We first establish the
existence and properties of the channel wave and scattering operators by using
the modern Mourre approach. We then use scattering theory to show the identity
of two apparently different representations of time delay. The first one is
defined in terms of sojourn times while the second one is given by the
Eisenbud-Wigner operator. The identity of these representations is well known
for systems where $V(x)$ vanishes as $|x| \to \infty$ ($V_\ell = V_r$). We show
that it remains true in the anisotropic case $V_\ell \not = V_r$, i.e. we prove
the existence of the time-dependent representation of time delay and its
equality with the time-independent Eisenbud-Wigner representation. Finally we
use this identity to give a time-dependent interpretation of the
Eisenbud-Wigner expression which is commonly used for time delay in the
literature.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 14:00:02 GMT"
}
]
| 2009-02-05T00:00:00 | [
[
"Amrein",
"W. O.",
""
],
[
"Jacquet",
"Philippe A.",
""
]
]
|
quant-ph/0610199 | Garry Bowen | Garry Bowen, Nilanjana Datta | Asymptotic entanglement manipulation of bipartite pure states | 7 pages, requires IEEEtran.cls | null | null | null | quant-ph | null | Entanglement of pure states of bipartite quantum systems has been shown to
have a unique measure in terms of the von Neumann entropy of the reduced states
of either of its subsystems. The measure is established under entanglement
manipulation of an asymptotically large number of copies of the states. In this
paper, different asymptotic measures of entanglement assigned to arbitrary
sequences of bipartite pure states are shown to coincide only when the sequence
is information stable, in terms of the quantum spectral information rates of
the sequence of subsystem states. Additional bounds on the optimal rates of
entanglement manipulation protocols in quantum information are also presented,
including bounds given by generalizations of the coherent information and the
relative entropy of entanglement.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 14:02:56 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Bowen",
"Garry",
""
],
[
"Datta",
"Nilanjana",
""
]
]
|
quant-ph/0610200 | Tomoyuki Yamakami | Tomoyuki Yamakami | Quantum List Decoding of Classical Block Codes of Polynomially Small
Rate from Quantumly Corrupted Codewords | (A4 size, 10 pt, 25 pages) A complete version of an extended abstract
that appeared in the Proceedings of the 13th Computing: The Australasian
Theory Symposium (CATS 2007), pp.153-162, Ballarat, Australia, January
30-February 2, 2007 | Baltic Journal of Modern Computing, Vol. 4 (2016), No. 4, pp.
753-788 | 10.22364/bjmc.2016.4.4 | null | quant-ph cs.CC cs.IT math.IT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Given a classical error-correcting block code, the task of quantum list
decoding is to produce from any quantumly corrupted codeword a short list
containing all messages whose codewords exhibit high "presence" in the
quantumly corrupted codeword. Efficient quantum list decoders have been used to
prove a quantum hardcore property of classical codes. However, the code rates
of all known families of efficiently quantum list-decodable codes are,
unfortunately, too small for other practical applications. To improve those
known code rates, we prove that a specific code family of polynomially small
code rate over a fixed code alphabet, obtained by concatenating generalized
Reed-Solomon codes as outer codes with Hadamard codes as inner codes, has an
efficient quantum list-decoding algorithm if its codewords have relatively high
codeword presence in a given quantumly corrupted codeword. As an immediate
application, we use the quantum list decodability of this code family to solve
a certain form of quantum search problems in polynomial time. When the codeword
presence becomes smaller, in contrast, we show that the quantum list
decodability of generalized Reed-Solomon codes with high confidence is closely
related to the efficient solvability of the following two problems: the noisy
polynomial interpolation problem and the bounded distance vector problem.
Moreover, assuming that NP is not included in BQP, we also prove that no
efficient quantum list decoder exists for the generalized Reed-Solomon codes.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 14:57:40 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Oct 2006 10:18:44 GMT"
},
{
"version": "v3",
"created": "Wed, 7 Sep 2011 02:52:01 GMT"
},
{
"version": "v4",
"created": "Thu, 13 Oct 2016 19:50:03 GMT"
},
{
"version": "v5",
"created": "Fri, 14 Oct 2016 16:38:13 GMT"
}
]
| 2017-09-15T00:00:00 | [
[
"Yamakami",
"Tomoyuki",
""
]
]
|
quant-ph/0610201 | Laurent Nottale | L. Nottale and T. Lehner | Numerical simulation of a macroscopic quantum-like experiment:
oscillating wave packet | 14 pages, 7 figures | null | null | null | quant-ph | null | We simulate the transformation of a classical fluid into a quantum-like
(super)-fluid by the application of a generalized quantum potential through a
retro-active loop. This numerical experiment is exemplified in the case of a
non-spreading oscillating wave packet in a harmonic potential. We find
signatures of a quantum-like behavior which are stable against various
perturbations.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 16:03:57 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Nottale",
"L.",
""
],
[
"Lehner",
"T.",
""
]
]
|
quant-ph/0610202 | Romain All\'eaume | Mehrdad Dianati (ENST Paris), Romain Alleaume (ENST Paris) | Architecture of the Secoqc Quantum Key Distribution network | 18 pages, 6 figures. Accepted for publication in the proceedings of
the IEEE QSEC 2007 workshop. This paper will be presented at the workshop, as
well as other aspects of the work related to the Secoqc network. Revised
version: one reference added | null | null | null | quant-ph | null | The European projet Secoqc (Secure Communication based on Quantum
Cryptography) aims at developing a global network for unconditionally secure
key distribution. This paper specifies the requirements and presents the
principles guiding the design of this network, and relevant to its architecture
and protocols.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 16:48:30 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Oct 2006 11:16:02 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Dianati",
"Mehrdad",
"",
"ENST Paris"
],
[
"Alleaume",
"Romain",
"",
"ENST Paris"
]
]
|
quant-ph/0610203 | John Preskill | Hoi-Kwong Lo, John Preskill | Security of quantum key distribution using weak coherent states with
nonrandom phases | supersedes quant-ph/0504209. (v2): 28 pages, uses qic.sty. Further
discussion of universal composability and of the double Mach-Zehnder scheme | Quant. Inf. Comput. 8 (2007) 431-458 | null | CALT-68-2577 | quant-ph | null | We prove the security of the Bennett-Brassard (BB84) quantum key distribution
protocol in the case where the key information is encoded in the relative phase
of a coherent-state reference pulse and a weak coherent-state signal pulse, as
in some practical implementations of the protocol. In contrast to previous
work, our proof applies even if the eavesdropper knows the phase of the
reference pulse, provided that this phase is not modulated by the source, and
even if the reference pulse is bright. The proof also applies to the case where
the key is encoded in the photon polarization of a weak coherent-state pulse
with a known phase, but only if the phases of the four BB84 signal states are
judiciously chosen. The achievable key generation rate scales quadratically
with the transmission in the channel, just as for BB84 with phase-randomized
weak coherent-state signals (when decoy states are not used). For the case
where the phase of the reference pulse is strongly modulated by the source, we
exhibit an explicit attack that allows the eavesdropper to learn every key bit
in a parameter regime where a protocol using phase-randomized signals is
provably secure.
| [
{
"version": "v1",
"created": "Mon, 23 Oct 2006 20:00:13 GMT"
},
{
"version": "v2",
"created": "Tue, 2 Jan 2007 21:34:42 GMT"
}
]
| 2008-02-27T00:00:00 | [
[
"Lo",
"Hoi-Kwong",
""
],
[
"Preskill",
"John",
""
]
]
|
quant-ph/0610204 | Rafael Sorkin | Rafael D. Sorkin (Perimeter Institute and Syracuse University) | Quantum Dynamics without the Wave Function | plainTeX, 24 pages, no figures. To appear in a special volume of {\it
Journal of Physics A: Mathematical and General} entitled ``The Quantum
Universe'' and dedicated to Giancarlo Ghirardi on the occasion of his 70th
birthday. Most current version is available at
http://www.physics.syr.edu/~sorkin/some.papers/ (or wherever my home-page may
be) | J.Phys.A40:3207-3222,2007 | 10.1088/1751-8113/40/12/S20 | null | quant-ph gr-qc hep-th math.LO | null | When suitably generalized and interpreted, the path-integral offers an
alternative to the more familiar quantal formalism based on state-vectors,
selfadjoint operators, and external observers. Mathematically one generalizes
the path-integral-as-propagator to a {\it quantal measure} $\mu$ on the space
$\Omega$ of all ``conceivable worlds'', and this generalized measure expresses
the dynamics or law of motion of the theory, much as Wiener measure expresses
the dynamics of Brownian motion. Within such ``histories-based'' schemes new,
and more ``realistic'' possibilities open up for resolving the philosophical
problems of the state-vector formalism. In particular, one can dispense with
the need for external agents by locating the predictive content of $\mu$ in its
sets of measure zero: such sets are to be ``precluded''. But unrestricted
application of this rule engenders contradictions. One possible response would
remove the contradictions by circumscribing the application of the preclusion
concept. Another response, more in the tradition of ``quantum logic'', would
accommodate the contradictions by dualizing $\Omega$ to a space of
``co-events'' and effectively identifying reality with an element of this dual
space.
| [
{
"version": "v1",
"created": "Tue, 24 Oct 2006 07:48:52 GMT"
}
]
| 2008-11-26T00:00:00 | [
[
"Sorkin",
"Rafael D.",
"",
"Perimeter Institute and Syracuse University"
]
]
|
quant-ph/0610205 | Jaromir Fiurasek | Jaromir Fiurasek, Nicolas J. Cerf | Optimal multicopy asymmetric Gaussian cloning of coherent states | 7 pages, 2 figures, RevTeX4 | Phys. Rev. A 75, 052335 (2007). | 10.1103/PhysRevA.75.052335 | null | quant-ph | null | We investigate the asymmetric Gaussian cloning of coherent states which
produces M copies from N input replicas, such that the fidelity of all copies
may be different. We show that the optimal asymmetric Gaussian cloning can be
performed with a single phase-insensitive amplifier and an array of beam
splitters. We obtain a simple analytical expression characterizing the set of
optimal asymmetric Gaussian cloning machines.
| [
{
"version": "v1",
"created": "Tue, 24 Oct 2006 13:31:31 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Fiurasek",
"Jaromir",
""
],
[
"Cerf",
"Nicolas J.",
""
]
]
|
quant-ph/0610206 | Z. D. Wang | L. B. Shao, Z. D. Wang, and D. Y. Xing | Implementation of quantum gates based on geometric phases accumulated in
the eigenstates of periodic invariant operators | 4 pages | Phys. Rev. A 75, 014301 (2007) | 10.1103/PhysRevA.75.014301 | null | quant-ph | null | We propose a new strategy to physically implement a universal set of quantum
gates based on geometric phases accumulated in the nondegenerate eigenstates of
a designated invariant operator in a periodic physical system. The system is
driven to evolve in such a way that the dynamical phase shifts of the invariant
operator eigenstates are the same (or {\it mod} $2\pi$) while the corresponding
geometric phases are nontrivial.
We illustrate how this strategy to work in a simple but typical NMR-type
qubit system.
| [
{
"version": "v1",
"created": "Tue, 24 Oct 2006 13:52:37 GMT"
}
]
| 2016-09-08T00:00:00 | [
[
"Shao",
"L. B.",
""
],
[
"Wang",
"Z. D.",
""
],
[
"Xing",
"D. Y.",
""
]
]
|
quant-ph/0610207 | Candadi Sukumar Dr. | C.V.Sukumar | Sum rules and the domain after the last node of an eigenstate | 17 pages | J.Phys. A: Math. Gen. 39 (2006) 14153-14163 | 10.1088/0305-4470/39/45/023 | null | quant-ph | null | It is shown that it is possible to establish sum rules that must be satisfied
at the nodes and extrema of the eigenstates of confining potentials which are
functions of a single variable. At any boundstate energy the Schroedinger
equation has two linearly independent solutions one of which is normalisable
while the other is not. In the domain after the last node of a boundstate
eigenfunction the unnormalisable linearly independent solution has a simple
form which enables the construction of functions analogous to Green's functions
that lead to certain sum rules. One set of sum rules give conditions that must
be satisfied at the nodes and extrema of the boundstate eigenfunctions of
confining potentials. Another sum rule establishes a relation between an
integral involving an eigenfunction in the domain after the last node and a sum
involving all the eigenvalues and eigenstates. Such sum rules may be useful in
the study of properties of confining potentials. The exactly solvable cases of
the particle in a box and the simple harmonic oscillator are used to illustrate
the procedure. The relations between one of the sum rules and two-particle
densities and a construction based on Supersymmetric Quantum Mechanics are
discussed.
| [
{
"version": "v1",
"created": "Tue, 24 Oct 2006 14:07:38 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Sukumar",
"C. V.",
""
]
]
|
quant-ph/0610208 | Paulo A. Nussenzveig | Alessandro S. Villar, Katiuscia N. Cassemiro, Kaled Dechoum, Antonio
Z. Khoury, Marcelo Martinelli, and Paulo Nussenzveig | Entanglement in the above-threshold optical parametric oscillator | 9 pages, 6 figs. Important reference for readers of quant-ph/0610197.
J. Opt. Soc. Am. B, Feature Issue on Optical Quantum-Information Science,
doc. ID 70938 (posted 5 September 2006, in press) | null | 10.1364/JOSAB.24.000249 | null | quant-ph | null | We investigate entanglement in the above-threshold Optical Parametric
Oscillator, both theoretically and experimentally, and discuss its potential
applications to quantum information. The fluctuations measured in the
subtraction of signal and idler amplitude quadratures are $\Delta^2 \hat
p_-=0.50(1)$, or $-3.01(9)$ dB, and in the sum of phase quadratures are
$\Delta^2 \hatq_+=0.73(1)$, or $-1.37(6)$ dB. A detailed experimental study of
the noise behavior as a function of pump power is presented, and discrepancies
with theory are discussed.
| [
{
"version": "v1",
"created": "Tue, 24 Oct 2006 15:31:09 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Villar",
"Alessandro S.",
""
],
[
"Cassemiro",
"Katiuscia N.",
""
],
[
"Dechoum",
"Kaled",
""
],
[
"Khoury",
"Antonio Z.",
""
],
[
"Martinelli",
"Marcelo",
""
],
[
"Nussenzveig",
"Paulo",
""
]
]
|
quant-ph/0610209 | Angelo Bassi | A. Bassi, G.C. Ghirardi | The Conway-Kochen argument and relativistic GRW models | 16 pages, RevTeX | Found. Phys. 37, 169 (2007) | 10.1007/s10701-006-9097-1 | null | quant-ph | null | In a recent paper, Conway and Kochen proposed what is now known as the "Free
Will theorem" which, among other things, should prove the impossibility of
combining GRW models with special relativity, i.e., of formulating
relativistically invariant models of spontaneous wavefunction collapse. Since
their argument basically amounts to a non-locality proof for any theory aiming
at reproducing quantum correlations, and since it was clear since very a long
time that any relativistic collapse model must be non-local in some way, we
discuss why the theorem of Conway and Kochen does not affect the program of
formulating relativistic GRW models.
| [
{
"version": "v1",
"created": "Tue, 24 Oct 2006 17:01:16 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Nov 2006 18:35:33 GMT"
},
{
"version": "v3",
"created": "Fri, 1 Dec 2006 10:47:07 GMT"
},
{
"version": "v4",
"created": "Mon, 22 Jan 2007 18:54:14 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Bassi",
"A.",
""
],
[
"Ghirardi",
"G. C.",
""
]
]
|
quant-ph/0610210 | Kai Eckert | O. Romero-Isart, K. Eckert, A. Sanpera | Quantum State Transfer in Spin-1 Chains | 4 pages, 4 figures, published version | Phys. Rev. A 75, 050303(R) (2007) | 10.1103/PhysRevA.75.050303 | null | quant-ph cond-mat.other | null | We study the transfer of quantum information through a Heisenberg spin-1
chain prepared in its ground state. We measure the efficiency of such a quantum
channel {\em via} the fidelity of retrieving an arbitrarily prepared state and
{\em via} the transfer of quantum entanglement. The Heisenberg spin-1 chain has
a very rich quantum phase diagram. We show that the phase boundaries are
reflected in sharp variations of the transfer efficiency. In the vicinity of
the border between the dimer and the ferromagnetic phase (in the conjectured
spin-nematic region), we find strong indications for a qualitative change of
the excitation spectrum. Moreover, we identify two regions of the phase diagram
which give rise to particularly high transfer efficiency; the channel might be
non-classical even for chains of arbitrary length, in contrast to spin-1/2
chains.
| [
{
"version": "v1",
"created": "Tue, 24 Oct 2006 18:44:38 GMT"
},
{
"version": "v2",
"created": "Tue, 21 Nov 2006 15:45:40 GMT"
},
{
"version": "v3",
"created": "Thu, 17 May 2007 08:26:55 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Romero-Isart",
"O.",
""
],
[
"Eckert",
"K.",
""
],
[
"Sanpera",
"A.",
""
]
]
|
quant-ph/0610211 | Xuexi Yi | X. X. Yi and W. Wang | Dissipation Effects in Hybrid Systems | 4+ pages, 4 figures | Phys Rev A 76,042109(2007) | 10.1103/PhysRevA.76.042109 | null | quant-ph | null | The dissipation effect in a hybrid system is studied in this Letter. The
hybrid system is a compound of a classical magnetic particle and a quantum
single spin. Two cases are considered. In the first case, we investigate the
effect of the dissipative quantum subsystem on the motion of its classical
partner. Whereas in the second case we show how the dynamics of the quantum
single spin are affected by the dissipation of the classical particle.
Extension to general dissipative hybrid systems is discussed.
| [
{
"version": "v1",
"created": "Wed, 25 Oct 2006 01:19:56 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Yi",
"X. X.",
""
],
[
"Wang",
"W.",
""
]
]
|
quant-ph/0610212 | Oliver Muelken | Antonio Volta, Oliver Muelken, and Alexander Blumen | Quantum transport on two-dimensional regular graphs | 22 pages, 11 figure, acceted for publication in J.Phys.A | J. Phys. A 39, 14997 (2006) | 10.1088/0305-4470/39/48/011 | null | quant-ph cond-mat.stat-mech | null | We study the quantum-mechanical transport on two-dimensional graphs by means
of continuous-time quantum walks and analyse the effect of different boundary
conditions (BCs). For periodic BCs in both directions, i.e., for tori, the
problem can be treated in a large measure analytically. Some of these results
carry over to graphs which obey open boundary conditions (OBCs), such as
cylinders or rectangles. Under OBCs the long time transition probabilities
(LPs) also display asymmetries for certain graphs, as a function of their
particular sizes. Interestingly, these effects do not show up in the marginal
distributions, obtained by summing the LPs along one direction.
| [
{
"version": "v1",
"created": "Wed, 25 Oct 2006 08:16:10 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Volta",
"Antonio",
""
],
[
"Muelken",
"Oliver",
""
],
[
"Blumen",
"Alexander",
""
]
]
|
quant-ph/0610213 | Philippe Courteille | S. Slama, S. Bux, G. Krenz, C. Zimmermann, Ph.W. Courteille | Superradiant Rayleigh scattering in a ring cavity | 4 pages, 4 figures | null | null | null | quant-ph | null | Collective interaction of light with an atomic gas can give rise to
superradiant instabilities. We experimentally study the sudden build-up of a
reverse light field in a laser-driven high-finesse ring cavity filled with
ultracold thermal or condensed atoms. While superradiant Rayleigh scattering
from atomic clouds is normally only observed at very low temperatures (i.e.
well below $1 \mu$K), the presence of the ring cavity enhances cooperativity
and allows for superradiance with thermal clouds as hot as several $10 \mu$K. A
characterization of the superradiance at various temperatures and cooperativity
parameters allows us to link it to the collective atomic recoil laser.
| [
{
"version": "v1",
"created": "Wed, 25 Oct 2006 09:26:11 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Slama",
"S.",
""
],
[
"Bux",
"S.",
""
],
[
"Krenz",
"G.",
""
],
[
"Zimmermann",
"C.",
""
],
[
"Courteille",
"Ph. W.",
""
]
]
|
quant-ph/0610214 | Miroslav Dob\v{s}\'i\v{c}ek | M. Dobsicek, G. Johansson, V.S. Shumeiko and G. Wendin | Arbitrary accuracy iterative phase estimation algorithm as a two qubit
benchmark | Improved error model. Dephasing is considered | null | 10.1103/PhysRevA.76.030306 | null | quant-ph cond-mat.mes-hall cond-mat.supr-con gr-qc math-ph math.MP | null | We discuss the implementation of an iterative quantum phase estimation
algorithm, with a single ancillary qubit. We suggest using this algorithm as a
benchmark for multi-qubit implementations. Furthermore we describe in detail
the smallest possible realization, using only two qubits, and exemplify with a
superconducting circuit. We discuss the robustness of the algorithm in the
presence of gate errors, and show that 7 bits of precision is obtainable, even
with very limited gate accuracies.
| [
{
"version": "v1",
"created": "Wed, 25 Oct 2006 13:33:18 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Oct 2006 11:50:34 GMT"
},
{
"version": "v3",
"created": "Thu, 12 Jul 2007 13:56:06 GMT"
}
]
| 2010-03-26T00:00:00 | [
[
"Dobsicek",
"M.",
""
],
[
"Johansson",
"G.",
""
],
[
"Shumeiko",
"V. S.",
""
],
[
"Wendin",
"G.",
""
]
]
|
quant-ph/0610215 | Serguey Mayburov NN | S. Mayburov | Restrictions on Information Transfer in Quantum Measurements and State
Collapse | 9 pages; Latex; more calculations and comments added | Int. J. Quant. Inf. 5 (2007) 279 | null | null | quant-ph | null | Information-theoretical restrictions on the information transfer in quantum
measurements are studied. They are derived for the measurement of system S by
detector D, registrated and processed by information system O. The formalism of
inference maps in Hilbert space is used for it; it permit to calculate O
restricted state which contains available for O information on S parameters.
It's shown that the principal information losses, inevitable in this formalism
and induced by Heisenberg commutation relations, stipulate the stochasticity of
measurement outcomes, registrated by O in the individual events.
| [
{
"version": "v1",
"created": "Wed, 25 Oct 2006 12:17:13 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 13:45:26 GMT"
}
]
| 2007-06-28T00:00:00 | [
[
"Mayburov",
"S.",
""
]
]
|
quant-ph/0610216 | Ingemar Bengtsson | Ingemar Bengtsson | Three ways to look at mutually unbiased bases | 18 pages. Talk at the Vaxjo Conference on Foundations of Probability
and Physics, June 2006 | null | 10.1063/1.2713445 | null | quant-ph | null | This is a review of the problem of Mutually Unbiased Bases in finite
dimensional Hilbert spaces, real and complex. Also a geometric measure of
"mubness" is introduced, and applied to some recent calculations in six
dimensions (partly done by Bjorck and by Grassl). Although this does not yet
solve any problem, some appealing structures emerge.
| [
{
"version": "v1",
"created": "Wed, 25 Oct 2006 13:32:05 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Bengtsson",
"Ingemar",
""
]
]
|
quant-ph/0610217 | Ling Zhou | Ling Zhou, Guo-Hui Yang | Entanglement reciprocation between atomic qubits and entangled coherent
state | 5 pages, 3 fighres. accepted by J Phys B | J. Phys. B: At. Mol. Opt. Phys. 39, (2006) 5143 | 10.1088/0953-4075/39/24/011 | null | quant-ph | null | Introducing classical fields, we can transfer entanglement completely from
discrete qubits into entangled coherent state. The entanglement also can be
retrieved from the continuous-variable state of the cavities to the atomic
qubits. Via postselection measure, atomic entangled state and entangled
coherent state can be mutual transformed fully.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 00:17:25 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Zhou",
"Ling",
""
],
[
"Yang",
"Guo-Hui",
""
]
]
|
quant-ph/0610218 | Ping Zhang | Zi-Gang Yuan, Ping Zhang, Shu-Shen Li | Loschmidt Echo and Berry phase of the quantum system coupled to the XY
spin chain: Proximity to quantum phase transition | 15 pages, 5 figures | null | 10.1103/PhysRevA.75.012102 | null | quant-ph | null | We study the Loschmidt echo (LE) of a coupled system consisting of a central
spin and its surrounding environment described by a general XY spin-chain
model. The quantum dynamics of the LE is shown to be remarkably influenced by
the quantum criticality of the spin chain. In particular, the decaying behavior
of the LE is found to be controlled by the anisotropy parameter of the spin
chain. Furthermore, we show that due to the coupling to the spin chain, the
ground-state Berry phase for the central spin becomes nonanalytical and its
derivative with respect to the magnetic parameter $\lambda$ in spin chain
diverges along the critical line $\lambda=1$, which suggests an alternative
measurement of the quantum criticality of the spin chain.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 03:41:58 GMT"
}
]
| 2015-06-26T00:00:00 | [
[
"Yuan",
"Zi-Gang",
""
],
[
"Zhang",
"Ping",
""
],
[
"Li",
"Shu-Shen",
""
]
]
|
quant-ph/0610219 | Yu Chang-shui | Chang-shui Yu, X. X. Yi and He-shan Song | Concurrence of superposition | 4 pages | Phys. Rev. A 75, 022332 (2007) | 10.1103/PhysRevA.75.022332 | null | quant-ph | null | The bounds on concurrence of the superposition state in terms of those of the
states being superposed are studied in this paper. The bounds on concurrence
are quite different from those on the entanglement measure based on von Neumann
entropy (Phys. Rev. Lett. 97, 100502 (2006)). In particular, a nonzero lower
bound can be provided if the states being superposed are properly constrained.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 05:48:01 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Yu",
"Chang-shui",
""
],
[
"Yi",
"X. X.",
""
],
[
"Song",
"He-shan",
""
]
]
|
quant-ph/0610220 | Cristian S. Calude | Cristian S. Calude | De-Quantising the Solution of Deutsch's Problem | 8 pages | null | null | CDMTCS Research Report 285 | quant-ph | null | Probably the simplest and most frequently used way to illustrate the power of
quantum computing is to solve the so-called {\it Deutsch's problem}. Consider a
Boolean function $f: \{0,1\} \to \{0,1\}$ and suppose that we have a
(classical) black box to compute it. The problem asks whether $f$ is constant
(that is, $f(0) = f(1)$) or balanced ($f(0) \not= f(1)$). Classically, to solve
the problem seems to require the computation of $f(0)$ and $ f(1)$, and then
the comparison of results. Is it possible to solve the problem with {\em only
one} query on $f$? In a famous paper published in 1985, Deutsch posed the
problem and obtained a ``quantum'' {\em partial affirmative answer}. In 1998 a
complete, probability-one solution was presented by Cleve, Ekert, Macchiavello,
and Mosca. Here we will show that the quantum solution can be {\it
de-quantised} to a deterministic simpler solution which is as efficient as the
quantum one. The use of ``superposition'', a key ingredient of quantum
algorithm, is--in this specific case--classically available.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 08:42:13 GMT"
}
]
| 2007-05-23T00:00:00 | [
[
"Calude",
"Cristian S.",
""
]
]
|
quant-ph/0610221 | Stefano Olivares | Stefano Olivares, Matteo G. A. Paris and Ulrik L. Andersen | Optimal cloning of coherent states by linear optics | 5 pages, 4 figures, presented at the 13th Central European Workshop
on Quantum Optics, May 23-27 2006, Vienna, Austria (Proceedings will be
published in "Acta Physica Hungarica"); reference added, Eq. (8) corrected | Acta Phys. Hung. B 26, 293 (2006) | 10.1556/APH.26.2006.3-4.9 | null | quant-ph | null | We describe an optical scheme for optimal Gaussian n to m cloning of coherent
states. The scheme, which generalizes a recently demonstrated scheme for 1 to 2
cloning, involves only linear optical components and homodyne detection.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 09:21:16 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Nov 2006 08:43:44 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Olivares",
"Stefano",
""
],
[
"Paris",
"Matteo G. A.",
""
],
[
"Andersen",
"Ulrik L.",
""
]
]
|
quant-ph/0610222 | Jean-Pierre Gazeau | Jean-Pierre Gazeau (APC), Jihad Mourad (APC), Julien Queva (APC) | Fuzzy de Sitter space-times via coherent states quantization | null | Dans Proceedings of the XXVIth Colloquium on Group Theorical
Methods in Physics (A Paraitre) - XXVIth Colloquium on Group Theorical
Methods in Physics, New-York : \'Etats-Unis d'Am\'erique (2006) | null | null | quant-ph gr-qc math-ph math.MP | null | A construction of the 2d and 4d fuzzy de Sitter hyperboloids is carried out
by using a (vector) coherent state quantization. We get a natural
discretization of the dS "time" axis based on the spectrum of Casimir operators
of the respective maximal compact subgroups SO(2) and SO(4) of the de Sitter
groups SO\_0(1,2) and SO\_0(1,4). The continuous limit at infinite spins is
examined.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 09:53:08 GMT"
}
]
| 2007-12-17T00:00:00 | [
[
"Gazeau",
"Jean-Pierre",
"",
"APC"
],
[
"Mourad",
"Jihad",
"",
"APC"
],
[
"Queva",
"Julien",
"",
"APC"
]
]
|
quant-ph/0610223 | Giovanna Morigi Dr | Giovanna Morigi, Ennio Arimondo | Two-photon and EIT-assisted Doppler cooling in a three-level cascade
system | 5 pages, 3 figures. Revised version, accepted for publication in
Phys. Rev A (Rapid Comm.) | Phys. Rev. A 75, 051404(R) (2007). | 10.1103/PhysRevA.75.051404 | null | quant-ph physics.atom-ph | null | Laser cooling is theoretically investigated in a cascade three-level scheme,
where the excited state of a laser-driven transition is coupled by a second
laser to a top, more stable level, as for alkali-earth atoms. The second laser
action modifies the atomic scattering cross section and produces temperatures
lower than those reached by Doppler cooling on the lower transition. When
multiphoton processes due to the second laser are relevant, an electromagnetic
induced transparency modifies the absorption of the first laser, and the final
temperature is controlled by the second laser parameters. When the intermediate
state is only virtually excited, the dynamics is dominated by the two-photon
process and the final temperature is determined by the spontaneous decay rate
of the top state.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 10:02:34 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Apr 2007 16:59:27 GMT"
}
]
| 2013-05-29T00:00:00 | [
[
"Morigi",
"Giovanna",
""
],
[
"Arimondo",
"Ennio",
""
]
]
|
quant-ph/0610224 | T. S. Mahesh Dr. | T. S. Mahesh and Dieter Suter | Quantum information processing using strongly-dipolar coupled nuclear
spins | 5 pages, 5 figures, Accepted in PRA | null | 10.1103/PhysRevA.74.062312 | null | quant-ph | null | Dipolar coupled homonuclear spins present challenging, yet useful systems for
quantum information processing. In such systems, eigenbasis of the system
Hamiltonian is the appropriate computational basis and coherent control can be
achieved by specially designed strongly modulating pulses. In this letter we
describe the first experimental implementation of the quantum algorithm for
numerical gradient estimation on the eigenbasis of a four spin system.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 10:50:32 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Mahesh",
"T. S.",
""
],
[
"Suter",
"Dieter",
""
]
]
|
quant-ph/0610225 | Zhang Peng | P. Zhang and L. You | Geometric phase of an atom in a magnetic storage ring | 7pages, 4 figures | Phys. Rev. A 74, 062110 (2006) | 10.1103/PhysRevA.74.052110 | null | quant-ph cond-mat.other | null | A magnetically trapped atom experiences an adiabatic geometric (Berry's)
phase due to changing field direction. We investigate theoretically such an
Aharonov-Bohm-like geometric phase for atoms adiabatically moving inside a
storage ring as demonstrated in several recent experiments. Our result shows
that this phase shift is easily observable in a closed loop interference
experiment, and thus the shift has to be accounted for in the proposed inertial
sensing applications. The spread in phase shift due to the atom transverse
distribution is quantified through numerical simulations.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 14:05:50 GMT"
},
{
"version": "v2",
"created": "Fri, 19 Jan 2007 16:19:19 GMT"
}
]
| 2009-11-13T00:00:00 | [
[
"Zhang",
"P.",
""
],
[
"You",
"L.",
""
]
]
|
quant-ph/0610226 | Bing He | Bing He, J\'anos A. Bergou | Programmable unknown quantum-state discriminators with multiple copies
of program and data: A Jordan basis approach | 12 pages in revtex4 | Phys. Rev. A 75, 032316, 2007 | 10.1103/PhysRevA.75.032316 | null | quant-ph | null | The discrimination of any pair of unknown quantum states is performed by
devices processing three parts of inputs: copies of the pair of unknown states
we want to discriminate are respectively stored in two program systems and
copies of data, which is guaranteed to be one of the unknown states, in a third
system. We study the efficiency of such programmable devices with the inputs
prepared with $n$ and $m$ copies of unknown qubits used as programs and data,
respectively. By finding a symmetry in the average inputs, we apply the Jordan
basis method to derive their optimal unambiguous discrimination and the
minimum-error discrimination schemes. The dependence of the optimal solutions
on the a prior probabilities of the mean input states is also demonstrated.
| [
{
"version": "v1",
"created": "Thu, 26 Oct 2006 16:16:33 GMT"
},
{
"version": "v2",
"created": "Thu, 26 Oct 2006 22:25:06 GMT"
},
{
"version": "v3",
"created": "Sat, 4 Nov 2006 18:26:05 GMT"
}
]
| 2016-08-16T00:00:00 | [
[
"He",
"Bing",
""
],
[
"Bergou",
"János A.",
""
]
]
|
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