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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9812008 | Victor Red'kov | V M Red'kov | Measure of irregularity for Dirac, Schwinger, Wu-Yang's bases in the
Abelian monopole theory and affecting of the gauge symmetry principle by
allowance of singularity in physics | 18 pages, latex209 | Nonlin.Phenom.Complex Syst. 5:95-107,2002 | null | null | quant-ph | null | In the literature concerning the monopole matter, three gauges: Dirac,
Schwinger, and Wu-Yang's, have been contrasted to each other, and the Wu-Yang's
often appears as the most preferable one. The article aims to analyse this view
by interpreting the monopole situation in terms of the conventioal Fourier
series theory; in particular, having relied on the Dirichlet theorem. It is
shown that the monopole case can be labelled as a very spesific and even rather
simple class of problems in the frame of that theory: all the three monopole
gauges amount to practicaly the same one-dimentional problem for functions
given on the interval [0,pi] having a single point of discontinuity; these
three vary only in its location.In addition, some general aspects of the
Aharonov-Bohm effect are discussed; the way of how any singular potentials such
as monopole's, being allowed in physics, touche the essence of the physical
gauge principle itself is considered.
| [
{
"version": "v1",
"created": "Wed, 2 Dec 1998 14:41:46 GMT"
}
] | 2011-09-15T00:00:00 | [
[
"Red'kov",
"V M",
""
]
] |
quant-ph/9812009 | Antoine Suarez | Antoine Suarez (Center for Quantum Philosophy, Zurich) | Does the quantum collapse make sense? Quantum Mechanics vs
Multisimultaneity in interferometer-series experiments | 18 pages Latex, 2 eps figures. Archive adapted version of an article
accepted for publication in Physics Letters A | Phys.Lett. A250 (1998) 39-47 | 10.1016/S0375-9601(98)00813-5 | null | quant-ph | null | It is argued that the three assumptions of quantum collapse, one photon-one
count, and relativity of simultaneity cannot hold together: Nonlocal
correlations can depend on the referential frames of the beam-splitters but not
of the detectors. New experiments using interferometers in series are proposed
which make it possible to test Quantum Mechanics vs Multisimultaneity.
| [
{
"version": "v1",
"created": "Wed, 2 Dec 1998 17:32:36 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Suarez",
"Antoine",
"",
"Center for Quantum Philosophy, Zurich"
]
] |
quant-ph/9812010 | Dien A. Rice | Barry C. Sanders and Dien A. Rice | Nonclassical Fields and the Nonlinear Interferometer | 21 pages, 2 figures | Phys.Rev. A61 (2000) 013805 | 10.1103/PhysRevA.61.013805 | null | quant-ph | null | We demonstrate several new results for the nonlinear interferometer, which
emerge from a formalism which describes in an elegant way the output field of
the nonlinear interferometer as two-mode entangled coherent states. We clarify
the relationship between squeezing and entangled coherent states, since a weak
nonlinear evolution produces a squeezed output, while a strong nonlinear
evolution produces a two-mode, two-state entangled coherent state. In between
these two extremes exist superpositions of two-mode coherent states manifesting
varying degrees of entanglement for arbitrary values of the nonlinearity. The
cardinality of the basis set of the entangled coherent states is finite when
the ratio $\chi / \pi$ is rational, where $\chi$ is the nonlinear strength. We
also show that entangled coherent states can be produced from product coherent
states via a nonlinear medium without the need for the interferometric
configuration. This provides an important experimental simplification in the
process of creating entangled coherent states.
| [
{
"version": "v1",
"created": "Thu, 3 Dec 1998 03:47:22 GMT"
},
{
"version": "v2",
"created": "Fri, 8 Oct 1999 10:37:22 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Sanders",
"Barry C.",
""
],
[
"Rice",
"Dien A.",
""
]
] |
quant-ph/9812011 | Andrea Raiteri | A. Raiteri | A realistic interpretation of the density matrix I: Basic concepts | LaTeX, 21 pages, no figures | null | null | null | quant-ph | null | A realistic interpretation of Schroedinger and Dirac equations for density
matrices is proposed, in which the difference between the position arguments of
the density matrix is considered as an objective extra space dimension.
"Particle" solutions are found, which are perfectly localized both in position
space and in momentum space (the position and momentum operators commute in the
density matrix representation); definitions for all observable quantities are
given and the values associated to the "particle" solutions are the correct
ones, both for the non-relativistic and the relativistic case. Finally, a
non-linear interaction (the electromagnetic one) is introduced in an attempt to
single out the "particle" solutions of the Dirac equation from all other
solutions; the dynamical evolution of the electromagnetic field is described by
the classical (unquantized) Maxwell equations.
| [
{
"version": "v1",
"created": "Fri, 4 Dec 1998 16:54:02 GMT"
},
{
"version": "v2",
"created": "Sat, 8 Jul 2000 06:09:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Raiteri",
"A.",
""
]
] |
quant-ph/9812012 | Jose L. Cereceda | Jose L. Cereceda | Maximally entangled states and the Bell inequality | 10 pages, LaTeX, no figures | Phys.Lett. A212 (1996) 123-129 | 10.1016/0375-9601(96)00026-6 | null | quant-ph | null | Kar's recent proof showing that a maximally entangled state of two spin-1/2
particles gives the largest violation of a Bell inequality is extended to N
spin-1/2 particles (with N greater than or equal to 3). In particular, it is
shown that all the states yielding a direct contradiction with the assumption
of local realism do generally consist of a superposition of maximally entangled
states.
| [
{
"version": "v1",
"created": "Sat, 5 Dec 1998 00:14:02 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cereceda",
"Jose L.",
""
]
] |
quant-ph/9812013 | Sougato Bose | S. Bose, V. Vedral and P. L. Knight | Purification via entanglement swapping and conserved entanglement | 4 pages, 2 figures, minor changes, to appear in Phys. Rev. A (tent:
July 99) | Phys.Rev. A60 (1999) 194 | 10.1103/PhysRevA.60.194 | null | quant-ph | null | We investigate the purification of entangled states by local actions using a
variant of entanglement swapping. We show that there exists a measure of
entanglement which is conserved in this type of purification procedure.
| [
{
"version": "v1",
"created": "Sun, 6 Dec 1998 20:25:54 GMT"
},
{
"version": "v2",
"created": "Sun, 18 Apr 1999 17:43:10 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Bose",
"S.",
""
],
[
"Vedral",
"V.",
""
],
[
"Knight",
"P. L.",
""
]
] |
quant-ph/9812014 | Giovanna Morigi | G. Morigi, J. Eschner, J.I. Cirac and P. Zoller | Laser Cooling of two trapped ions: Sideband cooling beyond the
Lamb-Dicke limit | 13 pages, 10 figures | Phys.Rev.A59:3797-3808,1999 | 10.1103/PhysRevA.59.3797 | null | quant-ph | null | We study laser cooling of two ions that are trapped in a harmonic potential
and interact by Coulomb repulsion. Sideband cooling in the Lamb-Dicke regime is
shown to work analogously to sideband cooling of a single ion. Outside the
Lamb-Dicke regime, the incommensurable frequencies of the two vibrational modes
result in a quasi-continuous energy spectrum that significantly alters the
cooling dynamics. The cooling time decreases nonlinearly with the linewidth of
the cooling transition, and the effect of trapping states which may slow down
the cooling is considerably reduced. We show that cooling to the ground state
is possible also outside the Lamb-Dicke regime. We develop the model and use
Quantum Monte Carlo calculations for specific examples. We show that a rate
equation treatment is a good approximation in all cases.
| [
{
"version": "v1",
"created": "Mon, 7 Dec 1998 15:29:05 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Morigi",
"G.",
""
],
[
"Eschner",
"J.",
""
],
[
"Cirac",
"J. I.",
""
],
[
"Zoller",
"P.",
""
]
] |
quant-ph/9812015 | Hrvoje Nikolic | H. Nikolic | Non-equal-time Poisson brackets | 4 pages, latex | null | null | null | quant-ph hep-th math-ph math.MP physics.class-ph | null | The standard definition of the Poisson brackets is generalized to the
non-equal-time Poisson brackets. Their relationship to the equal-time Poisson
brackets, as well as to the equal- and non-equal-time commutators, is
discussed.
| [
{
"version": "v1",
"created": "Mon, 7 Dec 1998 13:02:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Nikolic",
"H.",
""
]
] |
quant-ph/9812016 | Dagmar Bruss | D. Bruss and C. Macchiavello | Optimal state estimation for d-dimensional quantum systems | 3 pages | Phys.Lett. A253 (1999) 249-251 | 10.1016/S0375-9601(99)00099-7 | null | quant-ph | null | We establish a connection between optimal quantum cloning and optimal state
estimation for d-dimensional quantum systems. In this way we derive an upper
limit on the fidelity of state estimation for d-dimensional pure quantum states
and, furthermore, for generalized inputs supported on the symmetric subspace.
| [
{
"version": "v1",
"created": "Mon, 7 Dec 1998 13:27:32 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Bruss",
"D.",
""
],
[
"Macchiavello",
"C.",
""
]
] |
quant-ph/9812017 | Michael Mensky | Michael B. Mensky (P.N.Lebedev Physical Institute, Moscow, Russia) | Decoherence and the theory of continuous quantum measurements | 55 pages, latex, 4 figures in EPS | Phys.Usp.41:923-940,1998 | 10.1070/PU1998v041n09ABEH000442 | null | quant-ph | null | Decoherence of a quantum system (which then starts to display classical
features) results from the interaction of the system with the environment, and
is well described in the framework of the theory of continuous quantum
measurements (CQM). Reviewed are the various approaches to the CQM theory, and
the approach based on the effective complex Hamiltonians is discussed in
greater detail. The effective complex Hamiltonian is derived from the
restricted path integral, which emphasizes the role of information in the
dynamics of the system being measured. The complex Hamiltonian is used for
analyzing the CQM of energy in a two-level system. Such measurement is
demonstrated to be capable of monitoring the quantum transition, and the back
effect of monitoring on the probability of transition is analyzed. The
realization of this type of measurement by a long series of soft observations
of the system is presented.
| [
{
"version": "v1",
"created": "Mon, 7 Dec 1998 14:39:30 GMT"
},
{
"version": "v2",
"created": "Sat, 26 Dec 1998 18:47:15 GMT"
}
] | 2010-12-17T00:00:00 | [
[
"Mensky",
"Michael B.",
"",
"P.N.Lebedev Physical Institute, Moscow, Russia"
]
] |
quant-ph/9812018 | Gerard Milburn | G.J.Milburn and S.L.Braunstein | Quantum teleportation with squeezed vacuum states | null | null | 10.1103/PhysRevA.60.937 | null | quant-ph | null | We show how the partial entanglement inherent in a two mode squeezed vacuum
state admits two different teleportation protocols. These two protocols refer
to the different kinds of joint measurements that may be made by the sender.
One protocol is the recently implemented quadrature phase approach of
Braunstein and Kimble[Phys. Rev. Lett.{\bf 80}, 869 (1998)]. The other is based
on recognising that a two mode squeezed vacuum state is also entangled with
respect to photon number difference and phase sum. We show that this protocol
can also realise teleportation, however limitations can arise due to the fact
that the photon number spectrum is bounded from below by zero. Our examples
show that a given entanglement resource may admit more than a single
teleportation protocol and the question then arises as to what is the optimum
protocol in the general case.
| [
{
"version": "v1",
"created": "Tue, 8 Dec 1998 04:33:49 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Milburn",
"G. J.",
""
],
[
"Braunstein",
"S. L.",
""
]
] |
quant-ph/9812019 | Kirill Alekseev | Kirill N. Alekseev and Jan Perina | The 1/N-expansion, quantum-classical correspondence and nonclassical
states generation in dissipative higher-order anharmonic oscillators | 15 pages, RevTEX (EPSF-style), 3 figs. Replaced with final version
(stylistic corrections) | Physica Scripta 61(1) (2000) 7-16 | 10.1238/Physica.Regular.061a00007 | null | quant-ph chao-dyn nlin.CD physics.optics | null | We develop a method for the determination of thecdynamics of dissipative
quantum systems in the limit of large number of quanta N, based on the
1/N-expansion of Heidmann et al. [ Opt. Commun. 54, 189 (1985) ] and the
quantum-classical correspondence. Using this method, we find analytically the
dynamics of nonclassical states generation in the higher-order anharmonic
dissipative oscillators for an arbitrary temperature of a reservoir. We show
that the quantum correction to the classical motion increases with time
quadratically up to some maximal value, which is dependent on the degree of
nonlinearity and a damping constant, and then it decreases. Similarities and
differences with the corresponding behavior of the quantum corrections to the
classical motion in the Hamiltonian chaotic systems are discussed. We also
compare our results obtained for some limiting cases with the results obtained
by using other semiclassical tools and discuss the conditions for validity of
our approach.
| [
{
"version": "v1",
"created": "Wed, 9 Dec 1998 07:15:23 GMT"
},
{
"version": "v2",
"created": "Tue, 21 Dec 1999 02:56:32 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Alekseev",
"Kirill N.",
""
],
[
"Perina",
"Jan",
""
]
] |
quant-ph/9812020 | Mor Tal | Tal Mor | On the Disentanglement of States | 4 pages, RevTeX; email: [email protected] | null | null | null | quant-ph | null | Disentanglement is the process which transforms a state $\rho$ of two
subsystems into an unentangled state, while not effecting the reduced density
matrices of each of the two subsystems. Recently Terno showed that an arbitrary
state cannot be disentangled into a tensor product of its reduced density
matrices. In this letter we present various novel results regarding
disentanglement of states. Our main result is that there are sets of states
which cannot be successfuly disentangled (not even into a separable state).
Thus, we prove that a universal disentangling machine cannot exist.
| [
{
"version": "v1",
"created": "Wed, 9 Dec 1998 15:05:08 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mor",
"Tal",
""
]
] |
quant-ph/9812021 | Timothy C. Ralph | T.C.Ralph | All Optical Quantum Teleportation | 5 pages, 3 figures | Opt.Lett.24:348,1999 | 10.1364/OL.= | null | quant-ph | null | We propose an all optical, continuous variable, quantum teleportation scheme
based on optical parametric amplifiers.
| [
{
"version": "v1",
"created": "Thu, 10 Dec 1998 00:42:29 GMT"
}
] | 2009-07-09T00:00:00 | [
[
"Ralph",
"T. C.",
""
]
] |
quant-ph/9812022 | GuiHua Zeng | Guihua Zeng, Xinmei Wang | Quantum key distribution with authentication | 15 pages, no figures | null | null | null | quant-ph | null | The security of the previous quantum key distribution (QKD) protocols, which
is guaranteed by the nature of physics law, is based on the legitimate users.
However, impersonation of the legitimate communicators by eavesdroppers, in
practice, will be inevitable. In fact, the previous QKD protocols is unsecure
without authentication in practical communication. In this paper, we proposed
an improved QKD protocol that can simultaneously distribute the quantum secret
key and verify the communicators' identity. This presented authentication
scheme is provably secure.
| [
{
"version": "v1",
"created": "Thu, 10 Dec 1998 09:18:24 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Oct 1999 19:23:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zeng",
"Guihua",
""
],
[
"Wang",
"Xinmei",
""
]
] |
quant-ph/9812023 | Howard M. Wiseman | D. W. Berry, H. M. Wiseman, and Zhong-Xi Zhang | Heterodyne and adaptive phase measurements on states of fixed mean
photon number | 9 pages, 2 figures, minor changes from journal version | Phys. Rev. A 60, 2458 (1999) | 10.1103/PhysRevA.60.2458 | null | quant-ph | null | The standard technique for measuring the phase of a single mode field is
heterodyne detection. Such a measurement may have an uncertainty far above the
intrinsic quantum phase uncertainty of the state. Recently it has been shown
[H. M. Wiseman and R. B. Killip, Phys. Rev. A 57, 2169 (1998)] that an adaptive
technique introduces far less excess noise. Here we quantify this difference by
an exact numerical calculation of the minimum measured phase variance for the
various schemes, optimized over states with a fixed mean photon number. We also
analytically derive the asymptotics for these variances. For the case of
heterodyne detection our results disagree with the power law claimed by
D'Ariano and Paris [Phys. Rev. A 49, 3022 (1994)].
| [
{
"version": "v1",
"created": "Fri, 11 Dec 1998 07:07:44 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Sep 2002 09:15:19 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Berry",
"D. W.",
""
],
[
"Wiseman",
"H. M.",
""
],
[
"Zhang",
"Zhong-Xi",
""
]
] |
quant-ph/9812024 | R. E. Kastner | R. E. Kastner | TSQT `Elements of Possibility'? | 4 pages, latex | Stud.Hist.Philos.Mod.Phys. 30 (1999) 399-402 | null | null | quant-ph | null | I defend my arguments in quant-ph/9806002, which have recently been
criticized by L. Vaidman (quant-ph/9811092). I emphasize that the correct usage
of the ABL rule applies not to a genuine counterfactual statement but rather to
a conjunction of material conditionals. I argue that the only kind of valid
counterfactual statement one can make using the ABL rule is a ``might''
counterfactual, which is not adequate for the attribution of `elements of
reality' to a quantum system.
| [
{
"version": "v1",
"created": "Sat, 12 Dec 1998 06:09:09 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kastner",
"R. E.",
""
]
] |
quant-ph/9812025 | Luis Santos | L. Santos, M. Lewenstein, J. I. Cirac and Y. Castin | Laser Induced Condensation of Trapped Bosonic Gases | LaTeX, 4 pages, 3 eps figures | null | null | null | quant-ph | null | We demonstrate that an appropriate sequence of laser pulses allows to
condense a gas of trapped bosonic atoms into an arbitrary trap level.
Such condensation is robust, can be achieved in experimentally feasible
traps, and may lead to multistability and hysteresis phenomena.
| [
{
"version": "v1",
"created": "Sat, 12 Dec 1998 09:58:53 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Santos",
"L.",
""
],
[
"Lewenstein",
"M.",
""
],
[
"Cirac",
"J. I.",
""
],
[
"Castin",
"Y.",
""
]
] |
quant-ph/9812026 | Rafael Guardiola | F.M. Fernandez, R. Guardiola, J. Ros and M. Znojil | A family of complex potentials with real spectrum | Six figures and four tables | null | 10.1088/0305-4470/32/17/303 | null | quant-ph | null | We consider a two-parameter non hermitean quantum-mechanical hamiltonian that
is invariant under the combined effects of parity and time reversal
transformation. Numerical investigation shows that for some values of the
potential parameters the hamiltonian operator supports real eigenvalues and
localized eigenfunctions. In contrast with other PT symmetric models, which
require special integration paths in the complex plane, our model is integrable
along a line parallel to the real axis.
| [
{
"version": "v1",
"created": "Mon, 14 Dec 1998 08:15:35 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Fernandez",
"F. M.",
""
],
[
"Guardiola",
"R.",
""
],
[
"Ros",
"J.",
""
],
[
"Znojil",
"M.",
""
]
] |
quant-ph/9812027 | Miloslav Znojil | Miloslav Znojil | New perturbation method with the matching of wave functions | 19 pages, 1 figure, text re-submitted to Int. J. Quant. Chem | Int.J.Quant.Chem.79:235-242,2000 | null | null | quant-ph | null | We propose a new approach to the Rayleigh-Schr\"{o}dinger perturbation
expansions of bound states in quantum mechanics. We are inspired by the
enormous flexibility of solvable interactions with several (N) discontinuities.
Their standard matching solution is modified and transferred in perturbation
regime. We employ the global renormalization freedom of the local wave
functions and derive a compact N-dimensional matrix formula for corrections. In
applications, our recipe is shown non-numerical for all polynomial
perturbations of any piece-wise constant zero order potential.
| [
{
"version": "v1",
"created": "Mon, 14 Dec 1998 13:48:32 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Mar 2000 12:04:06 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Znojil",
"Miloslav",
""
]
] |
quant-ph/9812028 | Matteo G. A. Paris | Giacomo M. D'Ariano and Matteo G. A. Paris | Adaptive Quantum Homodyne Tomography | Latex (RevTex class + psfig), 9 Figs, Submitted to PRA | Phys.Rev. A60 (1999) 518 | 10.1103/PhysRevA.60.518 | null | quant-ph | null | An adaptive optimization technique to improve precision of quantum homodyne
tomography is presented. The method is based on the existence of so-called null
functions, which have zero average for arbitrary state of radiation. Addition
of null functions to the tomographic kernels does not affect their mean values,
but changes statistical errors, which can then be reduced by an optimization
method that "adapts" kernels to homodyne data. Applications to tomography of
the density matrix and other relevant field-observables are studied in detail.
| [
{
"version": "v1",
"created": "Mon, 14 Dec 1998 16:00:40 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"D'Ariano",
"Giacomo M.",
""
],
[
"Paris",
"Matteo G. A.",
""
]
] |
quant-ph/9812029 | null | H.Razmi, M.Golshani | Locality Is An Unnecessary Assumption of Bell's Theorem | 5 pages LaTeX | null | null | TMU-98-03 | quant-ph | null | Without imposing the locality condition,it is shown that quantum mechanics
cannot reproduce all the predictions of a special stochastic realistic model
used in certain spin-correlation experiments.This shows that the so-called
locality condition is an unnecessary assumption of Bell's theorem.
| [
{
"version": "v1",
"created": "Mon, 14 Dec 1998 16:28:15 GMT"
}
] | 2019-08-17T00:00:00 | [
[
"Razmi",
"H.",
""
],
[
"Golshani",
"M.",
""
]
] |
quant-ph/9812030 | M. Czachor | Marek Czachor | Quantum cryptography with polarizing interferometers | revtex, 4 pages, 1 ps figure | Phys.Lett. A257 (1999) 107-112 | 10.1016/S0375-9601(99)00326-6 | null | quant-ph | null | Cryptographic scheme proposed by Bennett, Brassard, and Mermin [Phys. Rev.
Lett. {\bf 68}, 557 (1992)] is reformulated in a version involving two
polarizing Mach-Zehnder interferometers. Such a form, although physically
equivalent to the original one, makes its security explicit, suggestive and
easy to explain to non-experts.
| [
{
"version": "v1",
"created": "Mon, 14 Dec 1998 18:19:02 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Czachor",
"Marek",
""
]
] |
quant-ph/9812031 | Stefan H. Myrskog | S.H. Myrskog, J.K. Fox, H.S. Moon, H.A. Kim, J.B. Kim, A.M. Steinberg | Modified "delta kick cooling" for studies of atomic tunneling | LaTeX, 8 pages 10 figures | null | null | null | quant-ph physics.atom-ph | null | We present progress towards a planned experiment on atomic tunneling of
ultra-cold Rb atoms. As a first step in this experiment we present a
realization of an improved form of "delta-kick cooling." By application of a
pulsed magnetic field, laser cooled Rb atoms are further cooled by a factor of
10 (in 1-D) over the temperature out of molasses. Temperatures below 700 nK are
observed. The technique can be used not only to cool without fundamental limit
(but conserving phase-space density), but also to focus atoms, and as a
spin-dependent probe.
| [
{
"version": "v1",
"created": "Mon, 14 Dec 1998 19:34:04 GMT"
},
{
"version": "v2",
"created": "Wed, 31 Mar 1999 21:32:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Myrskog",
"S. H.",
""
],
[
"Fox",
"J. K.",
""
],
[
"Moon",
"H. S.",
""
],
[
"Kim",
"H. A.",
""
],
[
"Kim",
"J. B.",
""
],
[
"Steinberg",
"A. M.",
""
]
] |
quant-ph/9812032 | Tomoyuki Yamakami | Tomoyuki Yamakami and Andrew C. Yao | NQP_{C} = co-C_{=}P | 9 pages. Accepted for Information Processing Letters, June, 1999 | Inform.Proc.Lett. 71 (1999) 63-69 | null | null | quant-ph cs.CC | null | Adleman, DeMarrais, and Huang introduced the nondeterministic quantum
polynomial-time complexity class NQP as an analogue of NP. Fortnow and Rogers
implicitly showed that, when the amplitudes are rational numbers, NQP is
contained in the complement of C_{=}P. Fenner, Green, Homer, and Pruim improved
this result by showing that, when the amplitudes are arbitrary algebraic
numbers, NQP coincides with co-C_{=}P. In this paper we prove that, even when
the amplitudes are arbitrary complex numbers, NQP still remains identical to
co-C_{=}P. As an immediate corollary, BQP differs from NQP when the amplitudes
are unrestricted.
| [
{
"version": "v1",
"created": "Mon, 14 Dec 1998 22:56:28 GMT"
},
{
"version": "v2",
"created": "Tue, 23 Mar 1999 22:04:33 GMT"
},
{
"version": "v3",
"created": "Mon, 26 Jul 1999 18:58:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Yamakami",
"Tomoyuki",
""
],
[
"Yao",
"Andrew C.",
""
]
] |
quant-ph/9812033 | Dietrich Leibfried | D. Leibfried | Individual addressing and state readout of trapped ions utilizing rf-
micromotion | 3 pages, 5 figures | null | 10.1103/PhysRevA.60.R3335 | null | quant-ph | null | A new scheme for the individual addressing of ions in a trap is described
that does not rely on light beams tightly focused onto only one ion. The scheme
utilizes ion micromotion that may be induced in a linear trap by dc offset
potentials. Thus coupling an individual ion to the globally applied light
fields corresponds to a mere switching of voltages on a suitable set of
compensation electrodes. The proposed scheme is especially suitable for
miniaturized rf (Paul) traps with typical dimensions of about 20-40 microns.
| [
{
"version": "v1",
"created": "Tue, 15 Dec 1998 13:12:08 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Leibfried",
"D.",
""
]
] |
quant-ph/9812034 | Massimiliano F. Sacchi | G. M. D'Ariano, C. Macchiavello and M. F. Sacchi | On the general problem of quantum phase estimation | 11 pages. Elsart package used | Phys.Lett. A248 (1998) 103 | 10.1016/S0375-9601(98)00702-6 | null | quant-ph | null | The problem of estimating a generic phase-shift experienced by a quantum
state is addressed for a generally degenerate phase shift operator. The optimal
positive operator-valued measure is derived along with the optimal input state.
Two relevant examples are analyzed: i) a multi-mode phase shift operator for
multipath interferometry; ii) the two mode heterodyne phase detection.
| [
{
"version": "v1",
"created": "Tue, 15 Dec 1998 15:01:58 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"D'Ariano",
"G. M.",
""
],
[
"Macchiavello",
"C.",
""
],
[
"Sacchi",
"M. F.",
""
]
] |
quant-ph/9812035 | Anthony Chefles | Anthony Chefles and Stephen M. Barnett | Strategies and Networks for State-Dependent Quantum Cloning | 12 pages, 6 eps figures, submitted to Phys. Rev. A | null | 10.1103/PhysRevA.60.136 | null | quant-ph | null | State-dependent cloning machines that have so far been considered either
deterministically copy a set of states approximately, or probablistically copy
them exactly. In considering the case of two equiprobable pure states, we
derive the maximum global fidelity of $N$ approximate clones given $M$ initial
exact copies, where $N>M$. We also consider strategies which interpolate
between approximate and exact cloning. A tight inequality is obtained which
expresses a trade-off between the global fidelity and success probability. This
inequality is found to tend, in the limit as $N{\to}{\infty}$, to a known
inequality which expresses the trade-off between error and inconclusive result
probabilities for state-discrimination measurements. Quantum-computational
networks are also constructed for the kinds of cloning machine we describe. For
this purpose, we introduce two gates: the distinguishability transfer and state
separation gates. Their key properties are described
| [
{
"version": "v1",
"created": "Tue, 15 Dec 1998 16:13:14 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Chefles",
"Anthony",
""
],
[
"Barnett",
"Stephen M.",
""
]
] |
quant-ph/9812036 | Atsushi Higuchi | Atsushi Higuchi (Maths Dept, Univ York) | Radiation reaction in quantum mechanics | 11 pages, REVTeX, no figures | null | null | null | quant-ph hep-th | null | The Lorentz-Dirac radiation reaction formula predicts that the position shift
of a charged particle due to the radiation reaction is of first order in
acceleration if it undergoes a small acceleration. A semi-classical calculation
shows that this is impossible at least if the acceleration is due to a
time-independent potential. Thus, the Lorentz-Dirac formula gives an incorrect
classical limit in this situation. The correct classical limit of the position
shift at the lowest order in acceleration is obtained by assuming that the
energy loss at each time is given by the Larmor formula.
| [
{
"version": "v1",
"created": "Tue, 15 Dec 1998 17:43:01 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Higuchi",
"Atsushi",
"",
"Maths Dept, Univ York"
]
] |
quant-ph/9812037 | Dorit Aharonov | Dorit Aharonov | Quantum Computation | 77 pages, figures included in the ps file. To appear in: Annual
Reviews of Computational Physics, ed. Dietrich Stauffer, World Scientific,
vol VI, 1998. The paper can be down loaded also from
http://www.math.ias.edu/~doria/ | null | 10.1142/9789812815569_0007 | null | quant-ph | null | In the last few years, theoretical study of quantum systems serving as
computational devices has achieved tremendous progress. We now have strong
theoretical evidence that quantum computers, if built, might be used as a
dramatically powerful computational tool. This review is about to tell the
story of theoretical quantum computation. I left out the developing topic of
experimental realizations of the model, and neglected other closely related
topics which are quantum information and quantum communication. As a result of
narrowing the scope of this paper, I hope it has gained the benefit of being an
almost self contained introduction to the exciting field of quantum
computation.
The review begins with background on theoretical computer science, Turing
machines and Boolean circuits. In light of these models, I define quantum
computers, and discuss the issue of universal quantum gates. Quantum
algorithms, including Shor's factorization algorithm and Grover's algorithm for
searching databases, are explained. I will devote much attention to
understanding what the origins of the quantum computational power are, and what
the limits of this power are. Finally, I describe the recent theoretical
results which show that quantum computers maintain their complexity power even
in the presence of noise, inaccuracies and finite precision. I tried to put all
results in their context, asking what the implications to other issues in
computer science and physics are. In the end of this review I make these
connections explicit, discussing the possible implications of quantum
computation on fundamental physical questions, such as the transition from
quantum to classical physics.
| [
{
"version": "v1",
"created": "Tue, 15 Dec 1998 23:42:50 GMT"
}
] | 2016-11-03T00:00:00 | [
[
"Aharonov",
"Dorit",
""
]
] |
quant-ph/9812038 | Dae-Yup | Dae-Yup Song | Unitary relations in time-dependent harmonic oscillators | Submitted to J. Phys. A | J. Phys. A: Math. Gen. 32 (1999) 3449-3456 | 10.1088/0305-4470/32/18/318 | null | quant-ph | null | For a harmonic oscillator with time-dependent (positive) mass and frequency,
an unitary operator is shown to transform the quantum states of the system to
those of a harmonic oscillator system of unit mass and time-dependent
frequency, as well as operators. For a driven harmonic oscillator, it is also
shown that, there are unitary transformations which give the driven system from
the system of same mass and frequency without driving force. The transformation
for a driven oscillator depends on the solution of classical equation of motion
of the driven system. These transformations, thus, give a simple way of finding
exact wave functions of a driven harmonic oscillator system, provided the
quantum states of the corresponding system of unit mass are given.
| [
{
"version": "v1",
"created": "Wed, 16 Dec 1998 08:19:13 GMT"
},
{
"version": "v2",
"created": "Mon, 19 Jul 1999 10:02:38 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Song",
"Dae-Yup",
""
]
] |
quant-ph/9812039 | Gerald V. Dunne | Carl M. Bender and Gerald V. Dunne | Large-order Perturbation Theory for a Non-Hermitian PT-symmetric
Hamiltonian | 5 pages, ReVTeX | J.Math.Phys. 40 (1999) 4616-4621 | 10.1063/1.532991 | null | quant-ph cond-mat hep-th | null | A precise calculation of the ground-state energy of the complex PT-symmetric
Hamiltonian $H=p^2+{1/4}x^2+i \lambda x^3$, is performed using high-order
Rayleigh-Schr\"odinger perturbation theory. The energy spectrum of this
Hamiltonian has recently been shown to be real using numerical methods. The
Rayleigh-Schr\"odinger perturbation series is Borel summable, and Pad\'e
summation provides excellent agreement with the real energy spectrum. Pad\'e
analysis provides strong numerical evidence that the once-subtracted
ground-state energy considered as a function of $\lambda^2$ is a Stieltjes
function. The analyticity properties of this Stieltjes function lead to a
dispersion relation that can be used to compute the imaginary part of the
energy for the related real but unstable Hamiltonian $H=p^2+{1/4}x^2-\epsilon
x^3$.
| [
{
"version": "v1",
"created": "Wed, 16 Dec 1998 13:54:24 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Bender",
"Carl M.",
""
],
[
"Dunne",
"Gerald V.",
""
]
] |
quant-ph/9812040 | L. F. Santos | L. F. Santos and C. O. Escobar | Enhanced Diffusion and the Continuous Spontaneous Localization Model | 5 pages, revtex(\tightenlines), no figures, minor corrections in the
text | null | 10.1103/PhysRevA.60.2712 | null | quant-ph chao-dyn nlin.CD | null | We find an analogy between turbulence and the dynamics of the continuous
spontaneous localization model (CSL) of the wave function. The use of a
standard white noise in the localization process gives Richardson's t^3 law for
the turbulent diffusion, while the introduction of an affine noise in the CSL
allows us to obtain the intermittency corrections to this law.
| [
{
"version": "v1",
"created": "Wed, 16 Dec 1998 15:46:23 GMT"
},
{
"version": "v2",
"created": "Mon, 12 Apr 1999 17:03:16 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Santos",
"L. F.",
""
],
[
"Escobar",
"C. O.",
""
]
] |
quant-ph/9812041 | Mihaly Benedict | Bal\'azs Moln\'ar, Mih\'aly G. Benedict | An algebraic construction of the coherent states of the Morse potential
based on SUSY QM | 7 pages, LATEX, added references, corrected typos | null | null | null | quant-ph | null | By introducing the shape invariant Lie algebra spanned by the SUSY ladder
operators plus the unity operator, a new basis is presented for the quantum
treatment of the one-dimensional Morse potential. In this discrete, complete
orthonormal set, which we call the pseudo number states, the Morse Hamiltonian
is tridiagonal. By using this basis we construct coherent states algebraically
for the Morse potential, in a close analogy with the harmonic oscillator. We
also show that there exists an unitary displacement operator creating these
coherent states from the ground state. We show that our coherent states form a
continuous and overcomplete set of states. They coincide with a class of states
constructed earlier by Nieto and Simmons by using the coordinate
representation. \pacs{3.65.Fd, 02.20.Sv, 42.50.-p}
| [
{
"version": "v1",
"created": "Wed, 16 Dec 1998 17:16:04 GMT"
},
{
"version": "v2",
"created": "Thu, 10 Jun 1999 14:36:51 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Molnár",
"Balázs",
""
],
[
"Benedict",
"Mihály G.",
""
]
] |
quant-ph/9812042 | Kurt Gottfried | Kurt Gottfried | Is the Statistical Interpretation of Quantum Mechanics Implied by the
Correspondence Principle ? | null | null | null | CLNS 98/1596 | quant-ph | null | The classical limit of the Schrodinger equation implies the orthodox
statistical interpretation for degrees of freedom in finite-dimensional
subspaces of the full Hilbert space, but the argument presented does not imply
the Born interpretation for degrees of freedom that have a classical
counterpart.
| [
{
"version": "v1",
"created": "Wed, 16 Dec 1998 22:29:44 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gottfried",
"Kurt",
""
]
] |
quant-ph/9812043 | Mauro Fortunato | Mauro Fortunato (1), Paolo Tombesi (1), and Wolfgang P. Schleich (2)
((1) Camerino University, (2) Universitaet Ulm) | Endoscopic Tomography and Quantum-Non-Demolition | RevTeX, 10 pages, 1 eps figure with psfig. To appear In Physical
Review A 59 (January 1999) | Phys.Rev. A59 (1999) 718 | 10.1103/PhysRevA.59.718 | null | quant-ph | null | We propose to measure the quantum state of a single mode of the radiation
field in a cavity---the signal field---by coupling it via a
quantum-non-demolition Hamiltonian to a meter field in a highly squeezed state.
We show that quantum state tomography on the meter field using balanced
homodyne detection provides full information about the signal state. We discuss
the influence of measurement of the meter on the signal field.
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 00:16:29 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Fortunato",
"Mauro",
"",
"Camerino University"
],
[
"Tombesi",
"Paolo",
"",
"Camerino University"
],
[
"Schleich",
"Wolfgang P.",
"",
"Universitaet Ulm"
]
] |
quant-ph/9812044 | Sara Schneider | S. Schneider and G.J. Milburn | Decoherence and fidelity in ion traps with fluctuating trap parameters | 11 pages, 4 figures | null | 10.1103/PhysRevA.59.3766 | null | quant-ph | null | We consider two different kinds of fluctuations in an ion trap potential:
external fluctuating electrical fields, which cause statistical movement
(``wobbling'') of the ion relative to the center of the trap, and fluctuations
of the spring constant, which are due to fluctuations of the ac-component of
the potential applied in the Paul trap for ions. We write down master equations
for both cases and, averaging out the noise, obtain expressions for the heating
of the ion. We compare our results to previous results for far-off resonance
optical traps and heating in ion traps. The effect of fluctuating external
electrical fields for a quantum gate operation (controlled-NOT) is determined
and the fidelity for that operation derived.
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 06:48:01 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Schneider",
"S.",
""
],
[
"Milburn",
"G. J.",
""
]
] |
quant-ph/9812045 | Martti Havukainen | Martti Havukainen, Stig Stenholm | Coherence properties of the stochastic oscillator | 9 pages, revtex, 15 figures | null | 10.1103/PhysRevA.60.621 | HIP-1998-78/TH | quant-ph | null | An oscillator with stochastic frequency is discussed as a model for
evaluating the quantum coherence properties of a physical system. It is found
that the choice of jump statistics has to be considered with care if unphysical
consequences are to be avoided. We investigate one such model, evaluate the
damping it causes, the decoherence rate and the correlations it results in and
the properties of the state for asymptotically long times. Also the choice of
initial state is discussed and its effect on the time evolution of the
correlations.
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 08:42:25 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Havukainen",
"Martti",
""
],
[
"Stenholm",
"Stig",
""
]
] |
quant-ph/9812046 | L. L. Salcedo | J. Caro and L.L. Salcedo | Impediments to mixing classical and quantum dynamics | RevTex, 21 pages. Title slightly modified and summary section added | Phys.Rev. A60 (1999) 842-852 | 10.1103/PhysRevA.60.842 | ugr-dfm-5/98 | quant-ph | null | The dynamics of systems composed of a classical sector plus a quantum sector
is studied. We show that, even in the simplest cases, (i) the existence of a
consistent canonical description for such mixed systems is incompatible with
very basic requirements related to the time evolution of the two sectors when
they are decoupled. (ii) The classical sector cannot inherit quantum
fluctuations from the quantum sector. And, (iii) a coupling among the two
sectors is incompatible with the requirement of physical positivity of the
theory, i.e., there would be positive observables with a non positive
expectation value.
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 09:24:06 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Apr 1999 08:54:25 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Caro",
"J.",
""
],
[
"Salcedo",
"L. L.",
""
]
] |
quant-ph/9812047 | Antonio Vidiella-Barranco | H. Moya-Cessa, A. Vidiella-Barranco, J.A. Roversi, Dagoberto S.
Freitas, and S.M. Dutra (Universidade Estadual de Campinas, Campinas, Brazil) | Long-time-scale revivals in ion traps | 8 pages, 2 figures, in RevTex. To appear in Phys.Rev. A 59 (01 March
1999) | Phys.Rev. A59 (1999) 2518 | 10.1103/PhysRevA.59.2518 | A 084-98 | quant-ph physics.atom-ph | null | In this contribution we investigate the interaction of a single ion in a trap
with laser beams. Our approach, based on unitary transformating the
Hamiltonian, allows its exact diagonalization without performing the Lamb-Dicke
approximation. We obtain a transformed Jaynes-Cummings type Hamiltonian, and we
demonstrate the existence of super-revivals in that system.
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 16:32:46 GMT"
}
] | 2015-08-12T00:00:00 | [
[
"Moya-Cessa",
"H.",
"",
"Universidade Estadual de Campinas, Campinas, Brazil"
],
[
"Vidiella-Barranco",
"A.",
"",
"Universidade Estadual de Campinas, Campinas, Brazil"
],
[
"Roversi",
"J. A.",
"",
"Universidade Estadual de Campinas, Campinas, Brazil"
],
[
"Freitas",
"Dagoberto S.",
"",
"Universidade Estadual de Campinas, Campinas, Brazil"
],
[
"Dutra",
"S. M.",
"",
"Universidade Estadual de Campinas, Campinas, Brazil"
]
] |
quant-ph/9812048 | Richard L. Hall | Richard L. Hall, Nasser Saad, and Attila B. von Keviczky | Matrix elements for a generalized spiked harmonic oscillator | 12 pages in plain tex with 1 ps figure | J.Math.Phys. 39 (1998) 6345-6352 | 10.1063/1.532641 | CUQM-70 | quant-ph math-ph math.MP | null | Closed-form expressions for the singular-potential integrals <m| x^-alpha |n>
are obtained with respect to the Gol'dman and Krivchenkov eigenfunctions for
the singular potential V(x) = B x^2 + A/x^2, B > 0, A >= 0. These formulas are
generalizations of those found earlier by use of the odd solutions of the
Schroedinger equation with the harmonic oscillator potential [Aguilera-Navarro
et al, J. Math. Phys. 31, 99 (1990)].
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 20:04:41 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Hall",
"Richard L.",
""
],
[
"Saad",
"Nasser",
""
],
[
"von Keviczky",
"Attila B.",
""
]
] |
quant-ph/9812049 | Tad Hogg | Tad Hogg | Single-Step Quantum Search Using Problem Structure | 39 pages, 12 figures. Revision describes further improvement with
multiple steps (section 7). See also
http://www.parc.xerox.com/dynamics/www/quantum.html | Int.J.Mod.Phys. C11 (2000) 739-773 | 10.1142/S0129183100000663 | null | quant-ph | null | The structure of satisfiability problems is used to improve search algorithms
for quantum computers and reduce their required coherence times by using only a
single coherent evaluation of problem properties. The structure of random k-SAT
allows determining the asymptotic average behavior of these algorithms, showing
they improve on quantum algorithms, such as amplitude amplification, that
ignore detailed problem structure but remain exponential for hard problem
instances. Compared to good classical methods, the algorithm performs better,
on average, for weakly and highly constrained problems but worse for hard
cases. The analytic techniques introduced here also apply to other quantum
algorithms, supplementing the limited evaluation possible with classical
simulations and showing how quantum computing can use ensemble properties of NP
search problems.
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 18:43:56 GMT"
},
{
"version": "v2",
"created": "Mon, 15 May 2000 22:09:07 GMT"
}
] | 2009-10-06T00:00:00 | [
[
"Hogg",
"Tad",
""
]
] |
quant-ph/9812050 | Doug Bilodeau | Doug Bilodeau | Why Quantum Mechanics is Hard to Understand | LATEX, 11 pages, no figures | null | null | null | quant-ph gr-qc hep-th | null | To understand the foundations of quantum mechanics, we have to think
carefully about how theoretical concepts are rooted in -- and limited by -- the
nature of experience, as Bohr attempted to show. Geometrical pictures of
physical phenomena are favored because of their clarity. Quantum phenomena,
however, do not permit them. Instead, the historical and dynamical aspects of
description diverge and must be expressed in different but complementary
languages. Objective historical facts are recorded in terms of objects, which
necessarily have an imprecise, empirical quality. Dynamics is based on
quantitative abstraction from recurring patterns. The "quantum of action" is
the discontinuity between these two ways of looking at the physical world.
| [
{
"version": "v1",
"created": "Thu, 17 Dec 1998 23:19:26 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bilodeau",
"Doug",
""
]
] |
quant-ph/9812051 | Jim McElwaine | Jim McElwaine | Random Hamiltonian Models and Quantum Prediction Algorithms | 25 pages, 11 figures, LaTeX2e | null | null | null | quant-ph | null | This paper describes an algorithm for selecting a consistent set within the
consistent histories approach to quantum mechanics and investigates its
properties. The algorithm select from among the consistent sets formed by
projections defined by the Schmidt decomposition by making projections at the
earliest possible time. The algorithm unconditionally predicts the possible
events in closed quantum systems and ascribes probabilities to these events. A
simple random Hamiltonian model is described and the results of applying the
algorithm to this model using computer programs are discussed and compared with
approximate analytic calculations.
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 10:33:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"McElwaine",
"Jim",
""
]
] |
quant-ph/9812052 | Gregoire Ribordy | G. Ribordy, J.-D. Gautier, N. Gisin, O. Guinnard, and H. Zbinden | Automated 'plug & play' quantum key distribution | 4 pages, 2 figures, HTML format | Electronics Letters, 29th October 1998, 34, (22), pp. 2116-2117 | null | null | quant-ph | null | An improved "plug & play" interferometric system for quantum key distribution
is presented. Self-alignment and compensation of birefringence remain, while
limitations due to reflections are overcome. Original electronics implementing
the BB84 protocol makes adjustment simple. Key creation with 0.1 photon per
pulse at a rate of 325 Hz with a 2.9 percent QBER - corresponding to a net rate
of 210Hz - over a 23 Km installed cable was performed.
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 15:42:23 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ribordy",
"G.",
""
],
[
"Gautier",
"J. -D.",
""
],
[
"Gisin",
"N.",
""
],
[
"Guinnard",
"O.",
""
],
[
"Zbinden",
"H.",
""
]
] |
quant-ph/9812053 | Jan-Ake Larsson | Jan-{\AA}ke Larsson, Sven Aerts and Marek Zukowski | Two-photon Franson-type interference experiments are not tests of local
realism | revtex, 4 pages with 4 figures | null | null | null | quant-ph | null | We report a local hidden-variable model which reproduces quantum predictions
for the two-photon interferometric experiment proposed by Franson [Phys. Rev.
Lett. 62, 2205 (1989)]. The model works for the ideal case of full visibility
and perfect detection efficiency. This result changes the interpretation of a
series of experiments performed in the current decade.
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 16:12:13 GMT"
}
] | 2022-03-16T00:00:00 | [
[
"Larsson",
"Jan-Åke",
""
],
[
"Aerts",
"Sven",
""
],
[
"Zukowski",
"Marek",
""
]
] |
quant-ph/9812054 | Christophe Coste | Christophe Coste (Laboratoire de Physique, ENS Lyon), Makoto Umeki
(Department of Physics, University of Tokyo), and Fernando Lund (Departamento
de F\'isica, Facultad de Ciencias F\'isicas y Matem\'aticas, Universidad de
Chile) | Scattering of dislocated wavefronts by vertical vorticity and the
Aharonov-Bohm effect I: Shallow water | 19 pages, 5 figures | Phys.Rev. E60 (1999) 4908-4916 | 10.1103/PhysRevE.60.4908 | null | quant-ph | null | When a surface wave interacts with a vertical vortex in shallow water the
latter induces a dislocation in the incident wavefronts that is analogous to
what happens in the Aharonov-Bohm effect for the scattering of electrons by a
confined magnetic field. In addition to this global similarity between these
two physical systems there is scattering. This paper reports a detailed
calculation of this scattering, which is quantitatively different from the
electronic case in that a surface wave penetrates the inside of a vortex while
electrons do not penetrate a solenoid. This difference, together with an
additional difference in the equations that govern both physical systems lead
to a quite different scattering in the case of surface waves, whose main
characteristic is a strong asymmetry in the scattering cross section. The
assumptions and approximations under which these effects happen are carefully
considered, and their applicability to the case of scattering of acoustic waves
by vorticity is noted.
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 16:18:34 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Coste",
"Christophe",
"",
"Laboratoire de Physique, ENS Lyon"
],
[
"Umeki",
"Makoto",
"",
"Department of Physics, University of Tokyo"
],
[
"Lund",
"Fernando",
"",
"Departamento\n de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de\n Chile"
]
] |
quant-ph/9812055 | Christophe Coste | Christophe Coste (Laboratoire de Physique, ENS Lyon) and Fernando Lund
(Departamento de F\'isica, Facultad de Ciencias F\'isicas y Matem\'aticas,
Universidad de Chile) | Scattering of dislocated wavefronts by vertical vorticity and the
Aharonov-Bohm effect II: Dispersive waves | 30 pages, 11 figures | Phys.Rev. E60 (1999) 4917-4925 | 10.1103/PhysRevE.60.4917 | null | quant-ph | null | Previous results on the scattering of surface waves by vertical vorticity on
shallow water are generalized to the case of dispersive water waves. Dispersion
effects are treated perturbatively around the shallow water limit, to first
order in the ratio of depth to wavelength. The dislocation of the incident
wavefront, analogous to the Aharonov-Bohm effect, is still observed. At short
wavelengths the scattering is qualitatively similar to the nondispersive case.
At moderate wavelengths, however, there are two markedly different scattering
regimes according to wether the capillary length is smaller or larger than
$\sqrt{3}$ times depth. The dislocation is characterized by a parameter that
depends both on phase and group velocity. The validity range of the calculation
is the same as in the shallow water case: wavelengths small compared to vortex
radius, and low Mach number. The implications of these limitations are
carefully considered.
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 16:21:21 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Coste",
"Christophe",
"",
"Laboratoire de Physique, ENS Lyon"
],
[
"Lund",
"Fernando",
"",
"Departamento de Física, Facultad de Ciencias Físicas y Matemáticas,\n Universidad de Chile"
]
] |
quant-ph/9812056 | Frederic Green | Stephen Fenner, Frederic Green, Steven Homer and Randall Pruim | Determining Acceptance Possibility for a Quantum Computation is Hard for
the Polynomial Hierarchy | null | null | null | null | quant-ph | null | It is shown that determining whether a quantum computation has a non-zero
probability of accepting is at least as hard as the polynomial time hierarchy.
This hardness result also applies to determining in general whether a given
quantum basis state appears with nonzero amplitude in a superposition, or
whether a given quantum bit has positive expectation value at the end of a
quantum computation. This result is achieved by showing that the complexity
class NQP of Adleman, Demarrais, and Huang, a quantum analog of NP, is equal to
the counting class coC$_=$P.
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 20:39:12 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fenner",
"Stephen",
""
],
[
"Green",
"Frederic",
""
],
[
"Homer",
"Steven",
""
],
[
"Pruim",
"Randall",
""
]
] |
quant-ph/9812057 | Michael Sipser | E. Farhi (MIT), J. Goldstone (MIT), S. Gutmann (Northeastern), M.
Sipser (MIT) | A Limit on the Speed of Quantum Computation for Insertion into an
Ordered List | 5 pages | null | null | MIT-CTP-2811 | quant-ph | null | We consider the problem of inserting a new item into an ordered list of N-1
items. The length of an algorithm is measured by the number of comparisons it
makes between the new item and items already on the list. Classically,
determining the insertion point requires log N comparisons. We show that, for N
large, no quantum algorithm can reduce the number of comparisons below log N/(2
loglog N).
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 20:44:14 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Farhi",
"E.",
"",
"MIT"
],
[
"Goldstone",
"J.",
"",
"MIT"
],
[
"Gutmann",
"S.",
"",
"Northeastern"
],
[
"Sipser",
"M.",
"",
"MIT"
]
] |
quant-ph/9812058 | Richard L. Hall | Richard L. Hall | Constructive inversion of energy trajectories in quantum mechanics | 16 pages in plain TeX with 5 ps figures | J.Math.Phys. 40 (1999) 699-707 | 10.1063/1.532712 | CUQM-71 | quant-ph math-ph math.MP | null | We suppose that the ground-state eigenvalue E = F(v) of the Schroedinger
Hamiltonian H = -\Delta + vf(x) in one dimension is known for all values of the
coupling v > 0. The potential shape f(x) is assumed to be symmetric, bounded
below, and monotone increasing for x > 0. A fast algorithm is devised which
allows the potential shape f(x) to be reconstructed from the energy trajectory
F(v). Three examples are discussed in detail: a shifted power-potential, the
exponential potential, and the sech-squared potential are each reconstructed
from their known exact energy trajectories.
| [
{
"version": "v1",
"created": "Fri, 18 Dec 1998 21:23:39 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Hall",
"Richard L.",
""
]
] |
quant-ph/9812059 | H. Dieter Zeh | H. D. Zeh | Why Bohm's Quantum Theory? | 5 pages, LaTeX. Several comments added. (To be published in
Foundations of Physics Letters) | Found.Phys.Lett. 12 (1999) 197-200 | 10.1023/A:1021669308832 | null | quant-ph gr-qc hep-th | null | This is a brief reply to Goldstein's article on ``Quantum Theory Without
Observers'' in Physics Today. It is pointed out that Bohm's pilot wave theory
is successful only because it keeps Schr\"odinger's (exact) wave mechanics
unchanged, while the rest of it is observationally meaningless and solely based
on classical prejudice.
| [
{
"version": "v1",
"created": "Mon, 21 Dec 1998 14:07:42 GMT"
},
{
"version": "v2",
"created": "Sat, 27 Mar 1999 17:08:26 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Zeh",
"H. D.",
""
]
] |
quant-ph/9812060 | Sean Hallgren | Lisa Hales and Sean Hallgren | Sampling Fourier Transforms on Different Domains | 17 pages. Preliminary draft | null | null | null | quant-ph | null | We isolate and generalize a technique implicit in many quantum algorithms,
including Shor's algorithms for factoring and discrete log. In particular, we
show that the distribution sampled after a Fourier transform over ${\mathbb
Z}_p$ can be efficiently approximated by transforming over ${\mathbb Z}_q$ for
any q in a large range. Our result places no restrictions on the superposition
to be transformed, generalizing the result implicit in Shor which applies only
to periodic superpositions. In addition, our proof easily generalizes to
multi-dimensional transforms for any constant number of dimensions.
| [
{
"version": "v1",
"created": "Mon, 21 Dec 1998 21:09:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hales",
"Lisa",
""
],
[
"Hallgren",
"Sean",
""
]
] |
quant-ph/9812061 | Hein Roehrig | Hein Roehrig (CWI, Amsterdam) | Searching an Ordered List on a Quantum Computer | Withdrawn by the author due to irreparable errors | null | null | null | quant-ph | null | Withdrawn by the author due to irreparable errors.
We present a quantum algorithm that in the black-box model performs a search
in an ordered list of N elements. Using 3/4 log N + O(1) queries, it achieves a
success probability of at least 1/2, whereas classically, log N - O(1) queries
are needed to obtain constant success probability. Moreover, our algorithm
employs the Haar transform and thus differs substantially from Grover's search
algorithm and from algorithms relying on the quantum Fourier transform.
| [
{
"version": "v1",
"created": "Tue, 22 Dec 1998 00:54:46 GMT"
},
{
"version": "v2",
"created": "Thu, 22 Apr 1999 23:41:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Roehrig",
"Hein",
"",
"CWI, Amsterdam"
]
] |
quant-ph/9812062 | Masahide Sasaki | Masahide Sasaki (1), Stephen M. Barnett (2), Richard Jozsa (3), Masao
Osaki (4) and Osamu Hirota (4) ((1)Communications Research
Laboratory,(2)University of Strathclyde,(3)University of Plymouth,(4)Tamagawa
University) | Accessible information and optimal strategies for real symmetrical
quantum sources | RevTeX, 16 pages, 4 eps figures with psfig, submitted to Phys. Rev.
A, corrected output error of Fig. 1 in the previous version | Phys.Rev. A59 (2002) 3325 | 10.1103/PhysRevA.59.3325 | null | quant-ph | null | We study the problem of optimizing the Shannon mutual information for sources
of real quantum states i.e. sources for which there is a basis in which all the
states have only real components. We consider in detail the sources ${\cal
E}_M$ of $M$ equiprobable qubit states lying symmetrically around the great
circle of real states on the Bloch sphere and give a variety of explicit
optimal strategies. We also consider general real group-covariant sources for
which the group acts irreducibly on the subset of all real states and prove the
existence of a real group-covariant optimal strategy, extending a theorem of
Davies (E. B. Davies, IEEE. Inf. Theory {\bf IT-24}, 596 (1978)). Finally we
propose an optical scheme to implement our optimal strategies, enough simple to
be realized with present technology.
| [
{
"version": "v1",
"created": "Tue, 22 Dec 1998 02:08:28 GMT"
},
{
"version": "v2",
"created": "Thu, 14 Jan 1999 09:04:28 GMT"
},
{
"version": "v3",
"created": "Mon, 18 Jan 1999 09:56:34 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Sasaki",
"Masahide",
""
],
[
"Barnett",
"Stephen M.",
""
],
[
"Jozsa",
"Richard",
""
],
[
"Osaki",
"Masao",
""
],
[
"Hirota",
"Osamu",
""
]
] |
quant-ph/9812063 | Hagen Kleinert | M. Bachmann, H. Kleinert, and A. Pelster | Variational Perturbation Theory for Density Matrices | Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of
paper also at
http://www.physik.fu-berlin.de/~kleinert/kleiner_re280/preprint.html | null | 10.1103/PhysRevA.60.3429 | null | quant-ph | null | We develop convergent variational perturbation theory for quantum statistical
density matrices. The theory is applicable to polynomial as well as
nonpolynomial interactions. Illustrating the power of the theory, we calculate
the temperature-dependent density of a particle in a double-well and of the
electron in a hydrogen atom.
| [
{
"version": "v1",
"created": "Tue, 22 Dec 1998 08:21:41 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Bachmann",
"M.",
""
],
[
"Kleinert",
"H.",
""
],
[
"Pelster",
"A.",
""
]
] |
quant-ph/9812064 | GuiHua Zeng | Guihua Zeng | A simple eavesdropping strategy of BB84 protocol | 10 pages, no figures | null | null | null | quant-ph | null | A simplified eavesdropping-strategy for BB84 protocol in quantum cryptography
(refer to quant-ph/9812022) is proposed. This scheme implements by the
`indirect copying' technology. Under this scheme, eavesdropper can exactly
obtain the exchanged information between the legitimate users without being
detected.
| [
{
"version": "v1",
"created": "Tue, 22 Dec 1998 13:17:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zeng",
"Guihua",
""
]
] |
quant-ph/9812065 | Simon Litsyn | G\'erard Cohen, Sylvia Encheva and Simon Litsyn | On binary constructions of quantum codes | LaTeX, 10 pages | null | null | null | quant-ph | null | Using the notion of generalized weight we improve estimates on the parameters
of quantum codes obtained by Steane's construction from binary codes. This
yields several new families of quantum codes.
| [
{
"version": "v1",
"created": "Tue, 22 Dec 1998 20:36:48 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cohen",
"Gérard",
""
],
[
"Encheva",
"Sylvia",
""
],
[
"Litsyn",
"Simon",
""
]
] |
quant-ph/9812066 | Victor Red'kov | V.M. Red'kov | On discrete symmetry for spin 1/2 and spin 1 particles in external
monopole field and quantum-mechanical property of self-conjugacy | 14 pages, latex209 | null | null | null | quant-ph | null | Particles of spin 1/2 and 1 in external Abelian monopole field are
considered. P-inversion like operators N-s commuting with the respective
Hamiltonians are constructed: N(bisp.) is diagonalized onto the relevant wave
functions, whereas N(vect.) does not. Such a paradox is rationalized through
noting that both these operators are not self-conjugate. It is shown that any
N-parity selection rules cannot be produced. Non-Abelian problems for doublets
of spin 1/2 and 1 particles are briefly discussed; the statement is given of
that corresponding discrete operators are self-conjugate and selection rules
are available.
| [
{
"version": "v1",
"created": "Wed, 23 Dec 1998 06:51:37 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Red'kov",
"V. M.",
""
]
] |
quant-ph/9812067 | Victor Red'kov | V.M. Red'kov | The doublet of Dirac fermions in the field of the non-Abelia monopole
and parity selection rules | 15 pages, latex209 | null | null | null | quant-ph | null | The paper concerns a problem of Dirac fermion doublet in the external
monopole potential arisen out of embedding the Abelian monopole solution in the
non-Abe- lian scheme. In this particular case, the Hamiltonian is invariant
under some symmetry operations consisting of an Abelian subgroup in the complex
rotational group SO(3.C). This symmetry results in a certain (A)-freedom in
choosing a discrete operator entering the complete set {H, j^{2}, j_{3}, N(A),
K} . The same complex number A represents a parameter of the wave functions
constructed. The generalized inversion-like operator N(A) implies its own
(A-dependent) de- finition for scalar and pseudoscalar, and further affords
some generalized N(A)-parity selection rules. It is shown that all different
sets of basis func- tions Psi(A) determine the same Hilbert space. In
particular, the functions Psi(A) decompose into linear combinations of
Psi(A=0). However, the bases con- sidered turn out to be nonorthogonal ones
when A is not real number; the latter correlates with the non-self-conjugacy
property of the operator N(A) at those A-s.
(This is a shortened version of the paper).
| [
{
"version": "v1",
"created": "Wed, 23 Dec 1998 07:16:00 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Red'kov",
"V. M.",
""
]
] |
quant-ph/9812068 | Guifre Vidal Bonafont | G. Vidal, J.I. Latorre, P. Pascual and R. Tarrach | Optimal minimal measurements of mixed states | 20 pages, no figures | Phys.Rev. A60 (1999) 126 | 10.1103/PhysRevA.60.126 | null | quant-ph | null | The optimal and minimal measuring strategy is obtained for a two-state system
prepared in a mixed state with a probability given by any isotropic a priori
distribution. We explicitly construct the specific optimal and minimal
generalized measurements, which turn out to be independent of the a priori
probability distribution, obtaining the best guesses for the unknown state as
well as a closed expression for the maximal mean averaged fidelity. We do this
for up to three copies of the unknown state in a way which leads to the
generalization to any number of copies, which we then present and prove.
| [
{
"version": "v1",
"created": "Wed, 23 Dec 1998 10:26:47 GMT"
},
{
"version": "v2",
"created": "Thu, 24 Dec 1998 09:11:40 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Vidal",
"G.",
""
],
[
"Latorre",
"J. I.",
""
],
[
"Pascual",
"P.",
""
],
[
"Tarrach",
"R.",
""
]
] |
quant-ph/9812069 | P. Zhou | Peng Zhou and S. Swain | Phase-dependent spectra in a driven two-level atom | 4 pages and 4 figures. Submitted to Phys. Rev. Lett | Phys.Rev.Lett. 82 (1999) 2500-2503 | 10.1103/PhysRevLett.82.2500 | null | quant-ph | null | We propose a method to observe phase-dependent spectra in resonance
fluorescence, employing a two-level atom driven by a strong coherent field and
a weak, amplitude-fluctuating field. The spectra are similar to those which
occur in a squeezed vacuum, but avoid the problem of achieving squeezing over a
$4\pi $ solid angle. The system shows other interesting features, such as
pronounced gain without population inversion.
| [
{
"version": "v1",
"created": "Wed, 23 Dec 1998 12:06:31 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Zhou",
"Peng",
""
],
[
"Swain",
"S.",
""
]
] |
quant-ph/9812070 | Martin Roetteler | Martin Roetteler, and Thomas Beth | Polynomial-Time Solution to the Hidden Subgroup Problem for a Class of
non-abelian Groups | 16 pages, LaTeX2e, 3 figures | null | null | null | quant-ph cs.ET | null | We present a family of non-abelian groups for which the hidden subgroup
problem can be solved efficiently on a quantum computer.
| [
{
"version": "v1",
"created": "Thu, 24 Dec 1998 00:27:39 GMT"
}
] | 2023-11-27T00:00:00 | [
[
"Roetteler",
"Martin",
""
],
[
"Beth",
"Thomas",
""
]
] |
quant-ph/9812071 | Valery Kalatsky | V.A.Kalatsky and V.L.Pokrovsky | Large Spins in External Fields | 26 pages, 21 pictures (pictures are called in via epsf.sty) | null | null | null | quant-ph | null | Spectra and magnetic properties of large spins $J$, placed into a crystal
electric field (CEF) of an arbitrary symmetry point group, are shown to change
drastically when $J$ changes by 1/2 or 1. At a fixed field symmetry and
configuration of its $N$ extrema situated at $p$-fold symmetry axis, physical
characteristics of the spin depend periodically on $J$ with the period equal to
$p$. The problem of the spectrum and eigenstates of the large spin $J$ is
equivalent to analogous problem for a scalar charged particle confined to a
sphere $S^2$ and placed into magnetic field of the monopole with the charge
$J$. This analogy as well as strong difference between close values of $J$
stems from the Berry's phase occurring in the problem. For energies close to
the extrema of the CEF, the problem can be formulated as Harper's equation on
the sphere. The $2J+1$-dimensional space of states is splitted into smaller
multiplets of classically degenerated states. These multiplets in turn are
splitted into submultiplets of states transforming according to specific
irreducible representations of the symmetry group determined by $J$ and $p$. We
classify possible configurations and corresponding spectra. Experimental
realizations of large spins in a symmetric environment are proposed and
physical effects observable in these systems are analyzed.
| [
{
"version": "v1",
"created": "Thu, 24 Dec 1998 02:43:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kalatsky",
"V. A.",
""
],
[
"Pokrovsky",
"V. L.",
""
]
] |
quant-ph/9812072 | A. F. Kracklauer | A. F. Kracklauer | EPR Correlations as an Angular Hanbury-Brown--Twiss Effect | 3 pages RevTeX; 2nd Revision: expository extentions & typo correction | null | null | null | quant-ph | null | It is shown that EPR correlations are the angular analogue to the
Hanbury-Brown--Twiss effect. As insight provided by this model, it is seen
that, analysis of the EPR experiment requires conditional probabilities which
do not admit the derivation of Bell inequalities.
| [
{
"version": "v1",
"created": "Thu, 24 Dec 1998 12:39:26 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jan 1999 02:27:18 GMT"
},
{
"version": "v3",
"created": "Thu, 25 Feb 1999 00:03:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kracklauer",
"A. F.",
""
]
] |
quant-ph/9812073 | Lauro Tomio | F.A.B. Coutinho, Y. Nogami and Lauro Tomio | Validity of Feynman's prescription of disregarding the Pauli principle
in intermediate states | null | null | 10.1103/PhysRevA.59.2624 | null | quant-ph hep-ph | null | Regarding the Pauli principle in quantum field theory and in many-body
quantum mechanics, Feynman advocated that Pauli's exclusion principle can be
completely ignored in intermediate states of perturbation theory. He observed
that all virtual processes (of the same order) that violate the Pauli principle
cancel out. Feynman accordingly introduced a prescription, which is to
disregard the Pauli principle in all intermediate processes. This ingeneous
trick is of crucial importance in the Feynman diagram technique. We show,
however, an example in which Feynman's prescription fails. This casts doubts on
the general validity of Feynman's prescription.
| [
{
"version": "v1",
"created": "Thu, 24 Dec 1998 18:21:54 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Coutinho",
"F. A. B.",
""
],
[
"Nogami",
"Y.",
""
],
[
"Tomio",
"Lauro",
""
]
] |
quant-ph/9812074 | Lauro Tomio | F.A.B. Coutinho, Y. Nogami and Lauro Tomio | Two definitions of the electric polarizability of a bound system in
relativistic quantum theory | null | null | 10.1119/1.19362 | null | quant-ph | null | For the electric polarizability of a bound system in relativistic quantum
theory, there are two definitions that have appeared in the literature. They
differ depending on whether or not the vacuum background is included in the
system. A recent confusion in this connection is clarified.
| [
{
"version": "v1",
"created": "Thu, 24 Dec 1998 18:43:34 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Coutinho",
"F. A. B.",
""
],
[
"Nogami",
"Y.",
""
],
[
"Tomio",
"Lauro",
""
]
] |
quant-ph/9812075 | Ignacio Cirac | J. I. Cirac, A. K. Ekert, and C. Macchiavello | Optimal purification of single qubits | 4 pages, 1 figure | Phys.Rev.Lett. 82 (1999) 4344-4347 | 10.1103/PhysRevLett.82.4344 | null | quant-ph | null | We introduce a new decomposition of the multiqubit states of the form
$\rho^{\otimes N}$ and employ it to construct the optimal single qubit
purification procedure. The same decomposition allows us to study optimal
quantum cloning and state estimation of mixed states.
| [
{
"version": "v1",
"created": "Sat, 26 Dec 1998 13:46:40 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cirac",
"J. I.",
""
],
[
"Ekert",
"A. K.",
""
],
[
"Macchiavello",
"C.",
""
]
] |
quant-ph/9812076 | Bose Institute | Somshubhro Bandyopadhyay, Guruprasad Kar | Is an optimal quantum cloner the best choice for local copying in
broadcasting entanglement? | temporarily withdrawn, email: [email protected] | null | null | null | quant-ph | null | The paper is temporarily withdrawn by the authors.
| [
{
"version": "v1",
"created": "Sat, 26 Dec 1998 18:57:27 GMT"
},
{
"version": "v2",
"created": "Mon, 4 Jan 1999 08:08:15 GMT"
},
{
"version": "v3",
"created": "Wed, 6 Jan 1999 09:57:58 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bandyopadhyay",
"Somshubhro",
""
],
[
"Kar",
"Guruprasad",
""
]
] |
quant-ph/9812077 | Wu Zuo-bing | Zuo-Bing Wu, Jin-Yan Zeng (Department of Physics, Peking University) | Extension Of Bertrand's Theorem And Factorization Of The Radial
Schr\"odinger Equation | 4 pages, 1 figuge | J.Math.Phys. 39 (1998) 5253-5259 | 10.1063/1.532568 | null | quant-ph | null | The Bertrand's theorem is extended, i.e. closed orbits still may exist for
other central potentials than the power law Coulomb potential and isotropic
harmonic oscillator. It is shown that for the combined potential
$V(r)=W(r)+b/r^2$ ($W(r)=ar^{\nu}$), when (and only when) $W(r)$ is the Coulomb
potential or isotropic harmonic oscillator, closed orbits still exist for
suitable angular momentum. The correspondence between the closeness of
classical orbits and the existence of raising and lowering operators derived
from the factorization of the radial Schr\"odinger equation is investigated.
| [
{
"version": "v1",
"created": "Sun, 27 Dec 1998 10:13:45 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Wu",
"Zuo-Bing",
"",
"Department of Physics, Peking University"
],
[
"Zeng",
"Jin-Yan",
"",
"Department of Physics, Peking University"
]
] |
quant-ph/9812078 | Michael Mensky | Michael B. Mensky (P.N.Lebedev Physical Institute, Moscow, Russia) | Decoherence and continuous measurements: Phenomenology and models | 10 pages, LATEX, 4 figures in EPS, to be published in Proceed. of the
conference "Decoherence: Theoretical, Experimental and Conceptual Problems",
Bielefeld, Germany, November 1998 | null | null | null | quant-ph | null | Decoherence of a quantum system induced by the interaction with its
environment (measuring medium) may be presented phenomenologically as a
continuous (or repeated) fuzzy quantum measurement. The dynamics of the system
subject to continuous decoherence (measurement) may be described by the
complex-Hamiltonian Schroedinger equation, stochastic Schroedinger equation of
a certain type or (nonselectively) by the Lindblad master equation. The
formulation of this dynamics with the help of restricted path integrals shows
that the dynamics of the measured system depends only on the information
recorded in the environment. With the help of the complex-Hamiltonian
Schroedinger equation, monitoring a quantum transition is shown to be possible,
at the price of decreasing the transition probability (weak Zeno effect). The
monitoring of the level transition may be realized by a long series of short
weak observations of the system which resulting in controllable slow
decoherence.
| [
{
"version": "v1",
"created": "Mon, 28 Dec 1998 10:04:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mensky",
"Michael B.",
"",
"P.N.Lebedev Physical Institute, Moscow, Russia"
]
] |
quant-ph/9812079 | Gov Shahar | S. Gov (1), S. Shtrikman (1+2), H. Thomas (3) ((1) The Department of
Complex Systems, Weizmann Institute of Science, Rehovot, Israel. (2) The
Department of Physics, University of California, San Diego, La Jolla, USA.
(3) The Department of Physics and Astronomy, University of Basel, Basel,
Switzerland) | Magnetic Trapping of Neutral Particles: A Study of a Physically
Realistic Model | 26 pages (amslatex), 1 EPS figure | null | null | null | quant-ph | null | We study, both classically and quantum-mechanically, the problem of a neutral
particle with spin S, mass m and magnetic moment mue, moving in two-dimensions
in an inhomogeneous magnetic field given by B_x=B'*x; B_y=-B'*y; B_z=B;
We identify K, the ratio between the precessional frequency of the particle
and its vibration frequency, as the relevant parameter of the problem.
Classicaly, we find that when the magnetic moment is antiparallel to B, the
particle is trapped provided that K<sqrt{4/27}. We also find that viscous
friction, be it translational or precessional, destabilizes the system.
Quantum-mechanically, we study the problem of spin S=h_bar/2 particle in the
same field. Treating K as a small parameter for the perturbation from the
adiabatic Hamiltonian, we find that the lifetime T_esc of the particle in its
trapped ground-state is T_esc={T_vib}/{128 pi^2} * exp{2/K} where T_vib is the
classical period of the particle when placed in the adiabatic potential V=mue
*|B(x,y)|
| [
{
"version": "v1",
"created": "Mon, 28 Dec 1998 08:49:32 GMT"
},
{
"version": "v2",
"created": "Tue, 18 May 1999 11:46:14 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gov",
"S.",
"",
"1+2"
],
[
"Shtrikman",
"S.",
"",
"1+2"
],
[
"Thomas",
"H.",
""
]
] |
quant-ph/9812080 | Jan Perina Jr | J. Perina, Jr., A. V. Sergienko, B. M. Jost, B. E. A. Saleh, M. C.
Teich (Boston University) | Dispersion in Femtosecond Entangled Two-Photon Interference | LATEX, 13 pages, 9 PostScript figures | Phys.Rev.A59:2359,1999 | 10.1103/PhysRevA.59.2359 | null | quant-ph | null | We theoretically investigate the quantum interference of entangled two-photon
states generated in a nonlinear crystal pumped by femtosecond optical pulses.
Interference patterns generated by the polarization analog of the
Hong-Ou-Mandel interferometer are studied. Attention is devoted to the effects
of the pump-pulse profile (pulse duration and chirp) and the second-order
dispersion in both the nonlinear crystal and the interferometer's optical
elements. Dispersion causes the interference pattern to have an asymmetric
shape. Dispersion cancellation occurs in some cases.
| [
{
"version": "v1",
"created": "Mon, 28 Dec 1998 12:03:32 GMT"
}
] | 2012-08-27T00:00:00 | [
[
"Perina,",
"J.",
"Jr.",
"Boston University"
],
[
"Sergienko",
"A. V.",
"",
"Boston University"
],
[
"Jost",
"B. M.",
"",
"Boston University"
],
[
"Saleh",
"B. E. A.",
"",
"Boston University"
],
[
"Teich",
"M. C.",
"",
"Boston University"
]
] |
quant-ph/9812081 | Arkadiusz Jadczyk | Ph. Blanchard and A. Jadczyk | A Way Out of the Quantum Trap | Replacement. Corrected affiliation. Latex, one .jpg figure. To appear
in Proc. Conf. Relativistic Quantum Measurements, Napoli 1998, Ed. F.
Petruccione | In "Open Systems and Measurement in Relativistic Quantum Theory",
Breuer, H.-P., Petruccione, F.,(Eds.), Lecture Notes in Physics,
Springer-Verlag, 1999 | 10.1007/BFb0104399 | null | quant-ph chao-dyn gr-qc math.PR nlin.CD | null | We review Event Enhanced Quantum Theory (EEQT). In Section 1 we address the
question "Is Quantum Theory the Last Word". In particular we respond to some of
recent challenging staments of H.P. Stapp. We also discuss a possible future of
the quantum paradigm - see also Section 5. In Section 2 we give a short sketch
of EEQT. Examples are given in Section 3. Section 3.3 discusses a completely
new phenomenon - chaos and fractal-like phenomena caused by a simultaneous
"measurement" of several non-commuting observables (we include picture of
Barnsley's IFS on unit sphere of a Hilbert space). In Section 4 we answer
"Frequently Asked Questions" concerning EEQT.
| [
{
"version": "v1",
"created": "Mon, 28 Dec 1998 18:45:40 GMT"
},
{
"version": "v2",
"created": "Thu, 31 Dec 1998 18:39:02 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Blanchard",
"Ph.",
""
],
[
"Jadczyk",
"A.",
""
]
] |
quant-ph/9812082 | Masanori Ohya | Viacheslav P Belavkin, Masanori Ohya | Quantum entanglements and entangled mutual entropy | 15 pages, Latex2e | Proc.Roy.Soc.Lond. A458 (2001) 209-232 | null | null | quant-ph | null | The mathematical structure of quantum entanglement is studied and classified
from the point of view of quantum compound states. We show that t he
classical-quantum correspondences such as encodings can be treated as dia gonal
(d-) entanglements. The mutual entropy of the d-compound and entangled states
lead to two different types of entropies for a given quantum state: t he von
Neumann entropy, which is achieved as the supremum of the information over all
d-entanglements, and the dimensional entropy, which is achieved at the standard
entanglement, the true quantum entanglement, coinciding with a d-entanglement
only in the case of pure marginal states. The q-capacity of a quantum noiseless
channel, defined as the supremum over all entanglements, i s given by the
logarithm of the dimensionality of the input algebra. It doub les the classical
capacity, achieved as the supremum over all d-entanglement s (encodings), which
is bounded by the logarithm of the dimensionality of a maximal Abelian
subalgebra.
| [
{
"version": "v1",
"created": "Wed, 30 Dec 1998 08:38:08 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Apr 2000 03:54:15 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Belavkin",
"Viacheslav P",
""
],
[
"Ohya",
"Masanori",
""
]
] |
quant-ph/9812083 | P. Zhou | Peng Zhou, Mao-Fa Fang, Qing-Ping Zhou, and Gao-Xiang Li | Narrow resonances with excitation of finite bandwidth field | 4 pages & 4 figures, Phys. Lett. A, (in press) | Phys.Lett. A251 (1999) 199-204 | 10.1016/S0375-9601(98)00893-7 | null | quant-ph | null | The effect of the laser linewidth on the resonance fluorescence spectrum of a
two-level atom is revisited. The novel spectral features, such as hole-burning
and dispersive profiles at line centre of the fluorescence spectrum are
predicted when the laser linewidth is much greater than its intensity. The
unique features result from quantum interference between different
dressed-state transition channels.
| [
{
"version": "v1",
"created": "Wed, 30 Dec 1998 16:51:55 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Zhou",
"Peng",
""
],
[
"Fang",
"Mao-Fa",
""
],
[
"Zhou",
"Qing-Ping",
""
],
[
"Li",
"Gao-Xiang",
""
]
] |
quant-ph/9812084 | P. Zhou | Peng Zhou and S. Swain | Optimal squeezing, pure states, and amplification of squeezing in
resonance fluorescence | 6 pages & 7 figures, Submitted to Phys. Rev. A | null | 10.1103/PhysRevA.59.3745 | null | quant-ph | null | It is shown that 100% squeezed output can be produced in the resonance
fluorescence from a coherently driven two-level atom interacting with a
squeezed vacuum. This is only possible for $N=1/8$ squeezed input, and is
associated with a pure atomic state, i.e., a completely polarized state. The
quadrature for which optimal squeezing occurs depends on the squeezing phase
$\Phi ,$ the Rabi frequency $\Omega ,$ and the atomic detuning $\Delta $. Pure
states are described for arbitrary $\Phi ,$ not just $\Phi =0$ or $\pi $ as in
previous work. For small values of $N,$ there may be a greater degree of
squeezing in the output field than the input - i.e., we have squeezing
amplification.
| [
{
"version": "v1",
"created": "Wed, 30 Dec 1998 16:57:33 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Zhou",
"Peng",
""
],
[
"Swain",
"S.",
""
]
] |
quant-ph/9812085 | Ulf Larsen | Ulf Larsen | Measuring the entangled Bell and GHZ aspects using a single-qubit
shuttle | 13 pages, revtex, 2 eps figures | null | null | null | quant-ph | null | A complete, non-demolition procedure is established for measuring multi-qubit
entangled states, such as the Bell-states and the GHZ-states, which is
essential in certain processes of quantum communication, computation, and
teleportation. No interaction between the individual parts of the entangled
system, nor with any environment is required. A small probe (e.g. a single
qubit) takes care of all interaction with the system, and is used repeatedly.
The probe-qubit interaction is of the simplest form, and only this one type of
interaction is required to perform a complete measurement. The process may be
divided into elementary local operations and interactions, taking place
sequentially as the probe visits each of the qubits. A shuttle mode is
described, which may be repeated indefinitely. By the quantum Zeno effect, the
entangled states can be maintained until released in a predictable state. This
shuttle process is stable, and self-correcting, by virtue of the standard
measurements performed repeatedly on the probe.
| [
{
"version": "v1",
"created": "Wed, 30 Dec 1998 20:58:52 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Larsen",
"Ulf",
""
]
] |
quant-ph/9812086 | Timothy F. Havel | T. F. Havel, S. S. Somaroo, C.-H. Tseng and D. G. Cory | Principles and Demonstrations of Quantum Information Processing by NMR
Spectroscopy | LaTeX, llncs style, 42 pages, 4 postscript figures; revisions include
a greatly expanded introduction to the NMR product operator formalism, and
substantial changes to the discussion of the NMR analogue of Hardy's paradox.
To appear in Applicable Algebra in Engineering, Communication and Computing | AAECC 10, 339-374 (2000) | null | null | quant-ph | null | This paper surveys our recent research on quantum information processing by
nuclear magnetic resonance (NMR) spectroscopy. We begin with a geometric
introduction to the NMR of an ensemble of indistinguishable spins, and then
show how this geometric interpretation is contained within an algebra of
multispin product operators. This algebra is used throughout the rest of the
paper to demonstrate that it provides a facile framework within which to study
quantum information processing more generally. The implementation of quantum
algorithms by NMR depends upon the availability of special kinds of mixed
states, called pseudo-pure states, and we consider a number of different
methods for preparing these states, along with analyses of how they scale with
the number of spins. The quantum-mechanical nature of processes involving such
macroscopic pseudo-pure states also is a matter of debate, and in order to
discuss this issue in concrete terms we present the results of NMR experiments
which constitute a macroscopic analogue Hardy's paradox. Finally, a detailed
product operator description is given of recent NMR experiments which
demonstrate a three-bit quantum error correcting code, using field gradients to
implement a precisely-known decoherence model.
| [
{
"version": "v1",
"created": "Thu, 31 Dec 1998 17:06:05 GMT"
},
{
"version": "v2",
"created": "Sat, 3 Jul 1999 17:36:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Havel",
"T. F.",
""
],
[
"Somaroo",
"S. S.",
""
],
[
"Tseng",
"C. -H.",
""
],
[
"Cory",
"D. G.",
""
]
] |
quant-ph/9812087 | Mr. Arindam Mitra Physics Group | Arindam Mitra | Complete Quantum Communication with Security | Latex, 15 pages, Final Version, Typo error corrected | null | null | null | quant-ph | null | The long-standing problem of quantum information processing is to remove the
classical channel from quantum communication. Introducing a new information
processing technique, it is discussed that both insecure and secure quantum
communications are possible without the requirement of classical channel.
| [
{
"version": "v1",
"created": "Thu, 31 Dec 1998 17:15:26 GMT"
},
{
"version": "v2",
"created": "Thu, 18 Feb 1999 13:21:39 GMT"
},
{
"version": "v3",
"created": "Mon, 10 May 1999 04:39:11 GMT"
},
{
"version": "v4",
"created": "Sun, 13 Jun 1999 13:31:36 GMT"
},
{
"version": "v5",
"created": "Wed, 15 Dec 1999 13:51:16 GMT"
},
{
"version": "v6",
"created": "Wed, 27 Sep 2000 14:31:52 GMT"
},
{
"version": "v7",
"created": "Thu, 1 Mar 2001 12:24:10 GMT"
},
{
"version": "v8",
"created": "Fri, 2 Mar 2001 11:37:38 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mitra",
"Arindam",
""
]
] |
quant-ph/9812088 | Adan Cabello | Adan Cabello | Quantum correlations are not local elements of reality | REVTeX, 3 pages | Phys.Rev. A59 (1999) 113 | 10.1103/PhysRevA.59.113 | null | quant-ph | null | I show a situation of multiparticle entanglement which cannot be explained in
the framework of an interpretation of quantum mechanics recently proposed by
Mermin. This interpretation is based on the assumption that correlations
between subsystems of an individual isolated composed quantum system are real
objective local properties of that system.
| [
{
"version": "v1",
"created": "Thu, 31 Dec 1998 19:13:18 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cabello",
"Adan",
""
]
] |
quant-ph/9901001 | Matthias Hug | M. Hug and G. J. Milburn | Quantum slow motion | null | null | null | null | quant-ph | null | We simulate the center of mass motion of cold atoms in a standing, amplitude
modulated, laser field as an example of a system that has a classical mixed
phase-space. We show a simple model to explain the momentum distribution of the
atoms taken after any distinct number of modulation cycles. The peaks
corresponding to a classical resonance move towards smaller velocities in
comparison to the velocities of the classical resonances. We explain this by
showing that, for a wave packet on the classical resonances, we can replace the
complicated dynamics in the quantum Liouville equation in phase-space by the
classical dynamics in a modified potential. Therefore we can describe the
quantum mechanical motion of a wave packet on a classical resonance by a purely
classical motion.
| [
{
"version": "v1",
"created": "Fri, 1 Jan 1999 09:41:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hug",
"M.",
""
],
[
"Milburn",
"G. J.",
""
]
] |
quant-ph/9901002 | Esposito Giampiero | Giampiero Esposito | Non-Fuchsian Singularities in Quantum Mechanics | 12 pages, plain Tex. In the final version, sections 2 and 3 are
entirely new | Found.Phys.Lett. 13 (2000) 29-40 | null | DSF preprint 99/1 | quant-ph | null | A modification of the spiked harmonic oscillator is studied in the case for
which the perturbation potential contains both an inverse power and a linear
term. It is then possible to evaluate trial functions by solving an integral
equation due to the occurrence of the linear term. The general form of such
integral equation is obtained by using a Green-function method, and adding a
modified Bessel function of second kind which solves an homogeneous problem
with Dirichlet boundary condition at the origin.
| [
{
"version": "v1",
"created": "Sat, 2 Jan 1999 11:53:29 GMT"
},
{
"version": "v2",
"created": "Thu, 1 Apr 1999 13:56:30 GMT"
},
{
"version": "v3",
"created": "Mon, 30 Aug 1999 14:33:09 GMT"
},
{
"version": "v4",
"created": "Wed, 13 Oct 1999 17:51:08 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Esposito",
"Giampiero",
""
]
] |
quant-ph/9901003 | Karlo Ayuel | K.Ayuel and P.F.de Chatel | The magnetic field generated by an electron bound in angular-momentum
eigenstates | This article is a long version of our article which will appear in
Eur. J.phys.20. It contains 22 pages 3 figures | Eur.J.Phys. 20 (1999) 53-58 | 10.1088/0143-0807/20/1/017 | null | quant-ph | null | The magnetic field generated by an electron bound in a spherically symmetric
potential is calculated for eigenstates of the orbital and total angular
momentum. General expressions are presented for the current density in such
states and the magnetic field is calculated through the vector potential, which
is obtained from the current density by direct integration. The method is
applied to the hydrogen atom, for which we reproduce and extend known results.
| [
{
"version": "v1",
"created": "Mon, 4 Jan 1999 15:13:52 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Ayuel",
"K.",
""
],
[
"de Chatel",
"P. F.",
""
]
] |
quant-ph/9901004 | Claus M. Granzow | C.M. Granzow and G. Mahler | Quantum trajectories of interacting pseudo-spin-networks | 15 pages, 12 figures | Appl.Phys. B67 (1998) 733-741 | 10.1007/s003400050573 | null | quant-ph | null | We consider quantum trajectories of composite systems as generated by the
stochastic unraveling of the respective Lindblad-master-equation. Their
classical limit is taken to correspond to local jumps between orthogonal
states. Based on statistical distributions of jump- and inter-jump-distances we
are able to quantify the non-classicality of quantum trajectories. To account
for the operational effect of entanglement we introduce the novel concept of
"co-jumps".
| [
{
"version": "v1",
"created": "Mon, 4 Jan 1999 15:50:27 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Granzow",
"C. M.",
""
],
[
"Mahler",
"G.",
""
]
] |
quant-ph/9901005 | Sheldon Goldstein | Sheldon Goldstein | Absence of Chaos in Bohmian Dynamics | 1 page | Phys.Rev. E60 (1999) 7578-7579 | 10.1103/PhysRevE.60.7578 | null | quant-ph | null | The Bohm motion for a particle moving on the line in a quantum state that is
a superposition of n+1 energy eigenstates is quasiperiodic with n frequencies.
| [
{
"version": "v1",
"created": "Wed, 6 Jan 1999 00:04:40 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Goldstein",
"Sheldon",
""
]
] |
quant-ph/9901006 | Jan Perina Jr | J. Perina, Jr. (1), J. Perina (2) ((1) Inst. of Physics AS CR, (2)
Palacky University) | Statistics of light in Raman and Brillouin nonlinear couplers | LATEX, 20 pages, 19 PostScript figures | Quant.Semiclass.Opt. 9 (1997) 443-464 | 10.1088/1355-5111/9/3/013 | null | quant-ph | null | Statistical properties of optical fields in nonlinear couplers composed of
two waveguides in which Raman or Brillouin processes (with classical pumping)
are in operation and which are mutually connected through the Stokes and/or
anti-Stokes linear interactions are investigated within the framework of
generalized superposition of coherent fields and quantum noise. Heisenberg
equations describing the couplers are solved both analytically under special
conditions and numerically in general cases. Regimes for nonclassical
properties of optical fields, such as sub-Poissonian photon-number statistics,
negative reduced moments of integrated intensity and squeezing of quadrature
fluctuations are discussed for the cases of single and compound fields. General
results are compared with those from short-length approximation.
| [
{
"version": "v1",
"created": "Wed, 6 Jan 1999 10:51:46 GMT"
}
] | 2012-08-27T00:00:00 | [
[
"Perina,",
"J.",
"Jr."
],
[
"Perina",
"J.",
""
]
] |
quant-ph/9901007 | Jan Perina Jr | J. Perina, Jr. (Institute of Physics of Charles University) | Interplay of creation, propagation, and relaxation of an excitation in a
dimer | LATEX, 19 pages, 16 PostScript figures | Chem.Phys. 236 (1998) 157-179 | null | null | quant-ph | null | Interplay of simultaneous creation, annihilation, propagation, and relaxation
of an excitation in molecular condensates interacting with an ultrashort
quantum optical pulse is studied in general and specialized to a dimer. A
microscopic model appropriate for such systems (with strong exciton-phonon
coupling) is presented. It also incorporates effects of (quantum) noise in the
optical field. A variety of new features in the initial stage of excitation
dynamics (when it is being created) is revealed; a strong influence of the
coherent excitation propagation on the processes of excitation creation and
annihilation in a molecule strongly interacting with phonons is the most
remarkable one.
| [
{
"version": "v1",
"created": "Wed, 6 Jan 1999 14:31:27 GMT"
}
] | 2012-08-27T00:00:00 | [
[
"Perina,",
"J.",
"Jr.",
"Institute of Physics of Charles University"
]
] |
quant-ph/9901008 | Joy Christian | Joy Christian (Oxford University) | Potentiality, Entanglement and Passion-at-a-Distance | 5 pages (TeX, uses mtexsis). Substantively expanded version. Soon to
appear in Studies in History and Philosophy of Modern Physics | Stud.Hist.Philos.Mod.Phys. 30 (1999) 561-567 | 10.1016/S1355-2198(99)00015-5 | null | quant-ph | null | This is a review of ``Potentiality, Entanglement and Passion-at-a-Distance:
Quantum Mechanical Studies for Abner Shimony, Volume Two''. The Festschrift
contains contributions from some of the most eminent workers in foundations of
quantum mechanics such as Aharonov, Anandan, Busch, d'Espagnat, Ghirardi,
Hardy, Howard, Mermin, Mittelstaedt, Peres, Popescu, Primas, Redhead, Rimini,
Rohrlich, Stachel, Stein, Vaidman, and Weber (along with a few others). In this
review of the Festschrift I have tried to give an overview (from my own
perspective) of the current state of the foundations of quantum mechanics --
especially with regard to the interpretational problems infesting the theory,
along with comments on several other significant lines of investigation.
| [
{
"version": "v1",
"created": "Wed, 6 Jan 1999 15:22:58 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Feb 1999 16:21:22 GMT"
},
{
"version": "v3",
"created": "Sat, 27 Feb 1999 14:13:18 GMT"
}
] | 2016-07-05T00:00:00 | [
[
"Christian",
"Joy",
"",
"Oxford University"
]
] |
quant-ph/9901009 | Hendry Izaac Elim | Hendry I. Elim | Exact Solution of the Energy Shift in each Quantum Mechanical Energy
Levels in a One Dimensional Symmetrical Linear Harmonic Oscillator | 7 pages, LaTeX2.09 | null | null | null | quant-ph cond-mat.stat-mech math-ph math.MP physics.chem-ph | null | An exact solution of the energy shift in each quantum mechanical energy
levels in a one dimensional symmetrical linear harmonic oscillator has been
investigated. The solution we have used here is firstly derived by manipulating
Schrodinger differential equation to be confluent hypergeometric differential
equation. The final exact numerical results of the energy shifts are then found
by calculating the final analytical solution of the confluent hypergeometric
equation with the use of a software (Mathcad Plus 6.0) or a program programmed
by using Turbo Pascal 7.0. We find that the results of the energy shift in our
exact solution method are almost the same as that in Barton et. al.
approximation method. Thus, the approximation constants (obliquity factors)
appeared in Barton et. al. method can also be calculated using the results of
the exact method.
| [
{
"version": "v1",
"created": "Thu, 7 Jan 1999 04:31:47 GMT"
},
{
"version": "v2",
"created": "Fri, 8 Jan 1999 04:17:11 GMT"
},
{
"version": "v3",
"created": "Mon, 11 Jan 1999 05:26:10 GMT"
},
{
"version": "v4",
"created": "Tue, 26 Jan 1999 09:26:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Elim",
"Hendry I.",
""
]
] |
quant-ph/9901010 | Willem M. de Muynck | Willem M. de Muynck | Preparation and measurement: two independent sources of uncertainty in
quantum mechanics | latex, 18 pages, 4 eps figures | Found.Phys. 30 (2000) 205-225 | null | null | quant-ph | null | In the Copenhagen interpretation the Heisenberg uncertainty relation is
interpreted as the mathematical expression of the concept of complementarity,
quantifying the mutual disturbance necessarily taking place in a simultaneous
or joint measurement of incompatible observables. This interpretation has
already been criticized by Ballentine a long time ago, and has recently been
challenged in an experimental way. These criticisms can be substantiated by
using the generalized formalism of positive operator-valued measures, from
which a new inequality can be derived, precisely illustrating the Copenhagen
concept of complementarity. The different roles of preparation and measurement
in creating uncertainty in quantum mechanics are discussed.
| [
{
"version": "v1",
"created": "Thu, 7 Jan 1999 11:38:22 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"de Muynck",
"Willem M.",
""
]
] |
quant-ph/9901011 | Victor Red'kov | V.M. Red'kov | The doublet of Dirac fermions in the field of the non-Abelian monopole,
isotopic chiral symmetry, and parity selection rules | 58 pages, latex209 | null | null | null | quant-ph | null | The paper concerns a problem of the Dirac fermion doublet in the external
monopole potential obtained by embedding the Abelian monopole solution in the
non-Abelian scheme. In this case, the doublet-monopole Hamiltonian is invariant
under operations consisting of a complex and one parametric Abelian subgroup in
S0(3.C). This symmetry results in a certain freedom in choosing a discrete
operator N(A) (A is a complex number) entering the complete set of quantum
variables. The same complex number A represents an additional parameter at the
basis functions. The generalized inversion like operator N(A) affords certain
generalized N(A)-parity selection rules. All the different sets of basis
functions Psi(A) determine the same Hilbert space. The functions Psi(A)
decompose into linear combinations of Psi(A=0): Psi(A) = F(A) Psi(A=0).
However, the bases considered turn out to be nonorthogonal ones when A is a
complex number; the latter correlates with the non-self-conjugacy of the N(A)
at complex A-s. The meaning of possibility to violate the quantum-mechanical
regulation on self-conjugacy as regards the operator N(A) is discussed. Also,
the problem of possible physical status for the matrix F(A) at real A-s is
considered in full detail: since the matrix belongs formally to the gauge group
SU(2), but being a symmetry for the Hamiltonian this F(A) generates linear
transformations on basis wave functions.
| [
{
"version": "v1",
"created": "Thu, 7 Jan 1999 10:59:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Red'kov",
"V. M.",
""
]
] |
quant-ph/9901012 | Michael Sipser | E. Farhi (MIT), J. Goldstone (MIT), S. Gutmann (Northeastern), M.
Sipser (MIT) | How many functions can be distinguished with k quantum queries? | 5 pages. Lower bound on sorting n items improved to (1-epsilon)n
quantum queries. Minor changes to text and corrections to references | null | 10.1103/PhysRevA.60.4331 | MIT-CTP-2814 | quant-ph | null | Suppose an oracle is known to hold one of a given set of D two-valued
functions. To successfully identify which function the oracle holds with k
classical queries, it must be the case that D is at most 2^k. In this paper we
derive a bound for how many functions can be distinguished with k quantum
queries.
| [
{
"version": "v1",
"created": "Thu, 7 Jan 1999 22:00:16 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Mar 1999 18:04:44 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Farhi",
"E.",
"",
"MIT"
],
[
"Goldstone",
"J.",
"",
"MIT"
],
[
"Gutmann",
"S.",
"",
"Northeastern"
],
[
"Sipser",
"M.",
"",
"MIT"
]
] |
quant-ph/9901013 | Luigi Foschini | Luigi Foschini | Questions on the concept of time | 4 pages, no figures | null | null | null | quant-ph | null | Some notes and questions about the concept of time are exposed. Particular
reference is given to the problem in quantum mechanics, in connection with the
indeterminacy principle.
| [
{
"version": "v1",
"created": "Fri, 8 Jan 1999 10:37:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Foschini",
"Luigi",
""
]
] |
quant-ph/9901014 | Massimiliano F. Sacchi | G. M. D'Ariano, M. F. Sacchi, and P. Kumar | Tomographic measurement of nonclassical radiation states | 5 pages, two columns, 8 eps figures, RevTex | Phys.Rev. A59 (1999) 826-830 | 10.1103/PhysRevA.59.826 | null | quant-ph | null | We propose to experimentally test the nonclassicality of quantum states
through homodyne tomography. For single-mode states we check violations of
inequalities involving the photon-number probability. For two-mode states we
test the nonclassicality by reconstructing some suitable number-operator
functions. The test can be performed with available quantum efficiency of
homodyne detection, by measuring the pertaining quantities on the corresponding
noisy states.
| [
{
"version": "v1",
"created": "Fri, 8 Jan 1999 11:01:15 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"D'Ariano",
"G. M.",
""
],
[
"Sacchi",
"M. F.",
""
],
[
"Kumar",
"P.",
""
]
] |
quant-ph/9901015 | Qiu-Yu Liu | Hong-Yi Fan (USTC, HeFei) and Q.Y. Liu (ICTP, Trieste) | Operator for Describing Polarization States of a Photon | This version (5 pages) will be published in the European Physical
Journal D | Eur.Phys.J. D8 (2000) 399-402 | 10.1007/s100530050050 | null | quant-ph | null | Based on the quantized electromagnetic field described by the
Riemann-Silberstein complex vector $F$, we construct the eigenvector set of $%
F$, which makes up an orthonormal and complete representation. In terms of $% F
$ we then introduce a new operator which can describe the relative ratio of the
left-handed and right-handed polarization states of a polarized photon .In
$F^{\prime}s$ eigenvector basis the operator manifestly exhibits a behaviour
which is similar to a phase difference between two orientations of polarization
of a light beam in classical optics.
| [
{
"version": "v1",
"created": "Fri, 8 Jan 1999 16:11:27 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Sep 1999 17:40:00 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Fan",
"Hong-Yi",
"",
"USTC, HeFei"
],
[
"Liu",
"Q. Y.",
"",
"ICTP, Trieste"
]
] |
quant-ph/9901016 | Jun Yan | Guang-jiong Ni, Jun Yan | Lamb shift calculated by simple noncovariant method | 9 pages, Revtex, 1 Postscript figure | null | null | null | quant-ph | null | The Lamb Shift (LS) of Hydrogenlike atom is evaluated by a simple method of
quantum electrodynamics in noncovariant form, based on the relativistic
stationary Schr\"odinger equation. An induced term proportional to
$\overrightarrow{p}^4$ in the effective Hamiltonian is emphasized. Perturbative
calculation of second order leads to the LS of $ 1S_{1/2}$ state and that of
$2S_{1/2}-2P_{1/2}$ states in H atom with the high accuracy within 0.1%
| [
{
"version": "v1",
"created": "Fri, 8 Jan 1999 18:29:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ni",
"Guang-jiong",
""
],
[
"Yan",
"Jun",
""
]
] |
quant-ph/9901017 | Sharon Jensen | H. Pierre Noyes | Thoughts on Commutation Relations and Measurement Accuracy | LaTex, 8 pages | null | null | SLAC-PUB-7772 | quant-ph | null | We show that measuring the trajectories of charged particles to finite
accuracy leads to the commutation relations needed for the derivation of the
free space Maxwell equations using the {\it discrete ordered calculus} (DOC).
We note that the finite step length derivation of the discrete difference
version of the single particle Dirac equation implies the discrete version of
the p,q commutation relations for a free particle. We speculate that a careful
operational analysis of the change in momenta occurring in a step-wise
continuous solution of the discrete Dirac equation could supply the missing
source-sink terms in the DOC derivation of the Maxwell equations, and lead to a
finite and discrete (``renormalized'') quantum electrodynamics (QED).
| [
{
"version": "v1",
"created": "Fri, 8 Jan 1999 18:52:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Noyes",
"H. Pierre",
""
]
] |
quant-ph/9901018 | Jun Yan | Guang-jiong Ni, Weimin Zhou and Jun Yan | Comparison among Klein-Gordon equation, Dirac equation and Relativistic
Stationary Schrodinger equation | 10 pages, Revtex, 10 Postscript figures | null | null | null | quant-ph | null | A particle is always not pure. It always contains hiding antiparticle
ingredient which is the essence of special relativity. Accordingly, the
Klein-Gordon (KG) equation and Dirac equation are restudied and compared with
the Relativistic Stationary Schr\"odinger Equation (RSSE). When an electron is
bound in a Hydrogenlike atom with pointlike nucleus having charge number $Z$,
the critical value of $Z, Z_c$, equals to 137 in Dirac equation whereas
$Z_c=\sqrt{M/\mu} (137)$ in RSSE with $M$ and $\mu$ being the total mass of
atom and the reduced mass of the electron.
| [
{
"version": "v1",
"created": "Fri, 8 Jan 1999 19:01:24 GMT"
},
{
"version": "v2",
"created": "Fri, 25 Feb 2000 07:43:13 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ni",
"Guang-jiong",
""
],
[
"Zhou",
"Weimin",
""
],
[
"Yan",
"Jun",
""
]
] |
quant-ph/9901019 | Shuichi Matsumoto | Shoju Kudaka and Shuichi Matsumoto | Uncertainty principle for proper time and mass | 15 pages, accepted for publication in J. Math. Phys | J.Math.Phys. 40 (1999) 1237-1245 | 10.1063/1.532797 | null | quant-ph | null | We review Bohr's reasoning in the Bohr-Einstein debate on the photon box
experiment. The essential point of his reasoning leads us to an uncertainty
relation between the proper time and the rest mass of the clock. It is shown
that this uncertainty relation can be derived if only we take the fundamental
point of view that the proper time should be included as a dynamic variable in
the Lagrangian describing the system of the clock. Some problems and some
positive aspects of our approach are then discussed.
| [
{
"version": "v1",
"created": "Sat, 9 Jan 1999 07:49:30 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Kudaka",
"Shoju",
""
],
[
"Matsumoto",
"Shuichi",
""
]
] |
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