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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9701030 | Dima V. Mozyrsky | L. Schulman and D. Mozyrsky (Clarkson University) | Measure of Entaglement | 4 pages, plain TeX, no figures | null | null | null | quant-ph | null | The extent to which a given wave function, $\psi$, is entangled is measured
by minimizing the norm of $\psi$ minus all possible unentangled functions. This
measure is given by the largest eigenvalue of $\psi^\dagger \psi$, considered
as an operator. The definition is basis independent.
| [
{
"version": "v1",
"created": "Thu, 23 Jan 1997 23:59:38 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Schulman",
"L.",
"",
"Clarkson University"
],
[
"Mozyrsky",
"D.",
"",
"Clarkson University"
]
] |
quant-ph/9701031 | Dima V. Mozyrsky | L. Schulman | Bounds on Decoherence and Error | 10 pages, plain TeX, no figures | Phys.Rev.A57:840-844,1998 | 10.1103/PhysRevA.57.840 | null | quant-ph | null | When a confined system interacts with its walls (treated quantum
mechanically), there is an intertwining of degrees of freedom. We show that
this need not lead to entanglement, hence decoherence. It will generally lead
to error. The wave function optimization required to avoid decoherence is also
examined.
| [
{
"version": "v1",
"created": "Fri, 24 Jan 1997 00:10:47 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Schulman",
"L.",
""
]
] |
quant-ph/9701032 | Mohammad Ardehali | M. Ardehali | Does Clauser-Horne-Shimony-Holt Correlation or Freedman-Clauser
Correlation lead to the largest violation of Bell's Inequality? | 15 pages, LaTeX file, no figures | null | 10.1103/PhysRevA.57.114 | null | quant-ph | null | An inequality is deduced from Einstein's locality and a supplementary
assumption. This inequality defines an experiment which can actually be
performed with present technology to test local realism. Quantum mechanics
violate this inequality a factor of 1.5. In contrast, quantum mechanics
violates previous inequalities (for example, Clauser-Horne-Shimony-Holt
inequality of 1969, Freedman-Clauser inequality of 1972, Clauser-Horne
inequality of 1974) by a factor of $\sqrt 2$. Thus the magnitude of violation
of the inequality derived in this paper is approximately $20.7%$ larger than
the magnitude of violation of previous inequalities. This result can be
particularly important for the experimental test of locality.
| [
{
"version": "v1",
"created": "Fri, 24 Jan 1997 08:45:42 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Ardehali",
"M.",
""
]
] |
quant-ph/9701033 | Jeong-Young Ji | Min-Ho Lee, Hyeong-Chan Kim and Jeong-Young Ji | Exact wave functions and geometric phases of a generalized driven
oscillator | 19 pages, revtex, no figures | J.KoreanPhys.Soc.31:560,1997 | null | KAIST-CHEP-96/8 | quant-ph hep-th | null | The generalized invariant and its eigenstates of a general quadratic
oscillator are found. The Schr\"odinger wave functions for the eigenstates are
also found in analytically closed forms. The conditions for the existence of
the cyclic initial state (CIS) are studied and the corresponding nonadiabatic
Berry phase is calculated explicitly.
| [
{
"version": "v1",
"created": "Fri, 24 Jan 1997 17:53:15 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lee",
"Min-Ho",
""
],
[
"Kim",
"Hyeong-Chan",
""
],
[
"Ji",
"Jeong-Young",
""
]
] |
quant-ph/9701034 | Vladimir Buzek | Mark Hillery and Vladimir Buzek | Quantum copying: Fundamental inequalities | 5 pages + 1 figure, LaTeX with revtex, epsfig submitted to Phys. Rev.
A | null | 10.1103/PhysRevA.56.1212 | null | quant-ph | null | How well one can copy an arbitrary qubit? To answer this question we consider
two arbitrary vectors in a two-dimensional state space and an abstract copying
transformation which will copy these two vectors. If the vectors are
orthogonal, then perfect copies can be made. If they are not, then errors will
be introduced. The size of the error depends on the inner product of the two
original vectors. We derive a lower bound for the amount of noise induced by
quantum copying. We examine both copying transformations which produce one copy
and transformations which produce many, and show that the quality of each copy
decreases as the number of copies increases.
| [
{
"version": "v1",
"created": "Fri, 24 Jan 1997 18:11:57 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Hillery",
"Mark",
""
],
[
"Buzek",
"Vladimir",
""
]
] |
quant-ph/9701035 | Walter Fusseder | Walter Fusseder | Comment on ``An Evolutionary Picture for Quantum Physics'' by Rudolf
Haag | 8 pages Latex, no figures, submitted to Communications in
Mathematical Physics | null | null | null | quant-ph | null | Widespread unjustified views on the role of the observer, the individuality
of quantum processes, the relation between decoherence and irreversibility,
Bell's quest for `beables', the direction of time, and the concept of
experience are revealed, whereby a better understanding is achieved of what the
evolutionary picture is all about and what is regarded as missing in already
existing realistic pictures.
| [
{
"version": "v1",
"created": "Mon, 27 Jan 1997 14:21:29 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fusseder",
"Walter",
""
]
] |
quant-ph/9701036 | Markus Simonius | Markus Simonius (ETH-Zuerich, Switzerland) | Quantum Interferometry, Measurement and Objectivity: Some Basic Features
Revisited | 5 pages, LaTeX, To be published in Proc. 2nd Interational Symposium
on Fundamental Problems in Quantum Physics, M. Ferrero and A. van der Merve
eds. (Kluwer Academic Publshers, 1997) | New Developments on Fundamental Problems in Quantum Physics, Ed.
Miguel Ferrero and Alwyn van der Merve (Kluwer Acad. Publ. 1997) 395 | null | null | quant-ph | null | The reduction paradigm of quantum interferometry and the objectivation
problem in quantum measurements are reanalyzed. Both are shown to be amenable
to straightforward mathematical treatment within "every-users" simple-minded
quantum mechanics without reduction postulate etc., using only its
probabilistic content.
| [
{
"version": "v1",
"created": "Tue, 28 Jan 1997 10:49:31 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Simonius",
"Markus",
"",
"ETH-Zuerich, Switzerland"
]
] |
quant-ph/9701037 | Holevo | A.S.Holevo (Steklov Mathematical Institute) | Covariant Quantum Dynamical Semigroups: Unbounded generators | 14 pages,Latex, no figures, submitted to the Semigroup Volume, Group
21, Goslar 1996 | null | 10.1007/BFb0106777 | null | quant-ph | null | A survey of the probabilistic approaches to quantum dynamical semigroups with
unbounded generators is given. An emphasis is made upon recent advances in the
structural theory of covariant Markovian master equations. The relations with
the classical Levy-Khinchin formula are elucidated. As an example, a complete
characterizations of the Galilean covariant irreversible quantum Markovian
evolutions is given in terms of the corresponding quantum master and Langevin
equations. Important topics for future investigation are outlined.
| [
{
"version": "v1",
"created": "Wed, 29 Jan 1997 11:06:03 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Holevo",
"A. S.",
"",
"Steklov Mathematical Institute"
]
] |
quant-ph/9701038 | Vladimir Buzek | V. Buzek, G. Drobny, G. Adam, R. Derka, P.L. Knight | Reconstruction of quantum states of spin systems via the Jaynes
principle of maximum entropy | 14 pages + 3 tables, LaTeX with revtex, to appear in J. Mod. Opt | null | 10.1080/09500349708231905 | null | quant-ph | null | We apply the Jaynes principle of maximum entropy for the partial
reconstruction of correlated spin states. We determine the minimum set of
observables which are necessary for the complete reconstruction of the most
correlated states of systems composed of spins-1/2 (e.g., the Bell and the
Greenberger-Horne-Zeilinger states). We investigate to what extent an
incomplete measurement can reveal nonclassical features of correlated spin
states.
| [
{
"version": "v1",
"created": "Thu, 30 Jan 1997 19:08:26 GMT"
}
] | 2016-06-29T00:00:00 | [
[
"Buzek",
"V.",
""
],
[
"Drobny",
"G.",
""
],
[
"Adam",
"G.",
""
],
[
"Derka",
"R.",
""
],
[
"Knight",
"P. L.",
""
]
] |
quant-ph/9701039 | Christopher A. Fuchs | Christopher A. Fuchs, Nicolas Gisin, Robert B. Griffiths, Chi-Sheng
Niu, and Asher Peres | Optimal Eavesdropping in Quantum Cryptography. I | 26 pages, LaTeX, no special macros, 3 PostScript figures | null | null | null | quant-ph | null | We consider the Bennett-Brassard cryptographic scheme, which uses two
conjugate quantum bases. An eavesdropper who attempts to obtain information on
qubits sent in one of the bases causes a disturbance to qubits sent in the
other basis. We derive an upper bound to the accessible information in one
basis, for a given error rate in the conjugate basis. Independently fixing the
error rate in the conjugate bases, we show that both bounds can be attained
simultaneously by an optimal eavesdropping probe, consisting of two qubits. The
qubits' interaction and their subsequent measurement are described explicitly.
These results are combined to give an expression for the optimal information an
eavesdropper can obtain for a given average disturbance when her interaction
and measurements are performed signal by signal. Finally, the relation between
quantum cryptography and violations of Bell's inequalities is discussed.
| [
{
"version": "v1",
"created": "Thu, 30 Jan 1997 20:05:05 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fuchs",
"Christopher A.",
""
],
[
"Gisin",
"Nicolas",
""
],
[
"Griffiths",
"Robert B.",
""
],
[
"Niu",
"Chi-Sheng",
""
],
[
"Peres",
"Asher",
""
]
] |
quant-ph/9702001 | Kalle-Antti Suominen | G. Massimo Palma, Kalle-Antti Suominen, Artur K. Ekert (Clarendon
Laboratory, University of Oxford, U.K.) | Quantum Computers and Dissipation | 20 pages, Latex, 7 Postscript figures | Proc.Roy.Soc.Lond. A452 (1996) 567-584 | 10.1098/rspa.1996.0029 | null | quant-ph | null | We analyse dissipation in quantum computation and its destructive impact on
efficiency of quantum algorithms. Using a general model of decoherence, we
study the time evolution of a quantum register of arbitrary length coupled with
an environment of arbitrary coherence length. We discuss relations between
decoherence and computational complexity and show that the quantum
factorization algorithm must be modified in order to be regarded as efficient
and realistic.
| [
{
"version": "v1",
"created": "Fri, 31 Jan 1997 06:56:27 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Palma",
"G. Massimo",
"",
"Clarendon\n Laboratory, University of Oxford, U.K."
],
[
"Suominen",
"Kalle-Antti",
"",
"Clarendon\n Laboratory, University of Oxford, U.K."
],
[
"Ekert",
"Artur K.",
"",
"Clarendon\n Laboratory, University of Oxford, U.K."
]
] |
quant-ph/9702002 | Ignacio Cirac | J. I. Cirac (University of Innsbruck) and N. Gisin (University of
Geneva) | Coherent eavesdropping strategies for the 4-state quantum cryptography
protocol | 6 pages of LaTeX and 3 eps figures. Submitted to Phys. Lett. A | null | 10.1016/S0375-9601(97)00176-X | null | quant-ph | null | An elementary derivation of best eavesdropping strategies for the 4 state
BB84 quantum cryptography protocol is presented, for both incoherent and
two--qubit coherent attacks. While coherent attacks do not help Eve to obtain
more information, they are more powerful to reveal the whole message sent by
Alice. Our results are based on symmetric eavesdropping strategies, which we
show to be sufficient to analyze these kind of problems.
| [
{
"version": "v1",
"created": "Fri, 31 Jan 1997 17:41:33 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Cirac",
"J. I.",
"",
"University of Innsbruck"
],
[
"Gisin",
"N.",
"",
"University of\n Geneva"
]
] |
quant-ph/9702003 | Dr N. Mavromatos | N.E. Mavromatos and D.V. Nanopoulos | Microtubules: The neuronic system of the neurons? | 20 pages LATEX, no figures; Invited talk by D.V.N. at the Workshop on
``Biophysics of Microtubules'', Texas Medical Center, Houston, Texas, April
1996 | null | null | ACT-04/97, CTP-TAMU-05/97 | quant-ph | null | In this talk we review recent work on integrable models for Microtubule (MT)
networks, subneural paracrystalline cytosceletal structures, which seem to play
a fundamental role in the neurons. We cast here the complicated MT dynamics in
the form of a 1+1-dimensional non-critical string theory, which can be
formulated in terms of (dual) Dirichlet branes, according to modern
perspectives. We suggest that the MTs are the microsites in the brain, for the
emergence of stable, macroscopic quantum coherent states, identifiable with the
``preconscious states''. Quantum space-time effects, as described by
non-critical string theory, trigger then an ``organized collapse'' of the
coherent states down to a specific or ``conscious state''. The whole process we
estimate to take O(1 sec), in excellent agreement with a plethora of
experimental/observational findings. The complete integrability of the stringy
model for MT proves sufficient in providing a satisfactory solution to memory
coding and capacity. Such features might turn out to be important for a model
of the brain as a quantum computer.
| [
{
"version": "v1",
"created": "Fri, 31 Jan 1997 18:46:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mavromatos",
"N. E.",
""
],
[
"Nanopoulos",
"D. V.",
""
]
] |
quant-ph/9702004 | Chi-Keung Chow | C.K. Au, Chi-Keung Chow, Chong-Sun Chu | Comment on ``A new efficient method for calculating perturbative
energies using functions which are not square integrable'': regularization
and justification | 6 pages in REVTeX, no figures | J.Phys.A30:4133-4136,1997 | 10.1088/0305-4470/30/11/036 | CLNS 97/1462, SISSA 15/97/FM | quant-ph | null | The method recently proposed by Skala and Cizek for calculating perturbation
energies in a strict sense is ambiguous because it is expressed as a ratio of
two quantities which are separately divergent. Even though this ratio comes out
finite and gives the correct perturbation energies, the calculational process
must be regularized to be justified. We examine one possible method of
regularization and show that the proposed method gives traditional quantum
mechanics results.
| [
{
"version": "v1",
"created": "Fri, 31 Jan 1997 20:01:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Au",
"C. K.",
""
],
[
"Chow",
"Chi-Keung",
""
],
[
"Chu",
"Chong-Sun",
""
]
] |
quant-ph/9702005 | Helmut Kroger | H. Kr\"oger | Generalized Aharonov-Bohm effect, homotopy classes and Hausdorff
dimension | 14 pages, LaTeX + 3 figures, PS | Phys.Lett. A226 (1997) 127-134 | 10.1016/S0375-9601(96)00928-0 | LAVAL-PHY-6-96 | quant-ph | null | We suggest as gedanken experiment a generalization of the Aharonov-Bohm
experiment, based on an array of solenoids. This experiment allows in principle
to measure the decomposition into homotopy classes of the quantum mechanical
propagator. This yields information on the geometry of the average path of
propagation and allows to determine its Hausdorff dimension.
| [
{
"version": "v1",
"created": "Fri, 31 Jan 1997 20:15:40 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Kröger",
"H.",
""
]
] |
quant-ph/9702006 | Hagen Kleinert | Hagen Kleinert and Sergei V. Shabanov | Proper Dirac Quantization of Free Particle on D-Dimensional Sphere | Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html Paper also at
http://www.physik.fu-berlin.de/~kleinert/kleiner_re253/preprint.html | Phys.Lett. A232 (1997) 327-332 | 10.1016/S0375-9601(97)00410-6 | null | quant-ph | null | We show that an unambiguous and correct quantization of the second-class
constrained system of a free particle on a sphere in $D$ dimensions is possible
only by converting the constraints to abelian gauge constraints, which are of
first class in Dirac's classification scheme. The energy spectrum is equal to
that of a pure Laplace-Beltrami operator with no additional constant arising
from the curvature of the sphere. A quantization of Dirac's modified Poisson
brackets for second-class constraints is also possible and unique, but must be
rejected since the resulting energy spectrum is physically incorrect.
| [
{
"version": "v1",
"created": "Sat, 1 Feb 1997 07:48:57 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Kleinert",
"Hagen",
""
],
[
"Shabanov",
"Sergei V.",
""
]
] |
quant-ph/9702007 | Martin Plenio | M.B. Plenio and P.L. Knight (Imperial College London) | The Quantum Jump Approach to Dissipative Dynamics in Quantum Optics | 104 pages + 30 figures, review article for Reviews of Modern Physics | Rev.Mod.Phys.70:101-144,1998 | 10.1103/RevModPhys.70.101 | null | quant-ph | null | Dissipation, the irreversible loss of energy and coherence, from a
microsystem, is the result of coupling to a much larger macrosystem (or
reservoir) which is so large that one has no chance of keeping track of all of
its degrees of freedom. The microsystem evolution is then described by tracing
over the reservoir states, resulting in an irreversible decay as excitation
leaks out of the initially excited microsystems into the outer reservoir
environment. Earlier treatments of this dissipation described an ensemble of
microsystems using density matrices, either in Schroedinger picture with Master
equations, or in Heisenberg picture with Langevin equations. The development of
experimental techniques to study single quantum systems (for example single
trapped ions, or cavity radiation field modes) has stimulated the construction
of theoretical methods to describe individual realizations conditioned on a
particular observation record of the decay channel, in the environment. These
methods, variously described as Quantum Jump, Monte Carlo Wavefunction and
Quantum Trajectory methods are the subject of this review article. We discuss
their derivation, apply them to a number of current problems in quantum optics
and relate them to ensemble descriptions.
| [
{
"version": "v1",
"created": "Sat, 1 Feb 1997 17:31:38 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Plenio",
"M. B.",
"",
"Imperial College London"
],
[
"Knight",
"P. L.",
"",
"Imperial College London"
]
] |
quant-ph/9702008 | null | J. Twamley (Imperial College, London, UK) | Quantised motion of an atom in a Gaussian-Laguerre beam | 13 pages Latex, RevTex, multicol, epsfig, 15 figures (large),
submitted to Phys. Rev. A (revised) | null | null | null | quant-ph | null | We quantise the centre of mass motion of a neutral Cs atom in the presence of
a classical Gaussian-Laguerre$_{10}$ light field in the large detuning limit.
This light field possesses orbital angular momentum which is transferred to the
atom via spontaneous emissions. We use quantum trajectory and analytic methods
to solve the master equation for the 2d centre of mass motion with recoil near
the centre of the beam. For appropriate parameters, we observe heating in both
the cartesian and polar observables within a few orbits of the atom in the
beam. The angular momentum, $\hat{L}$, shows a rapid diffusion which results in
$<\hat{L}>$ reaching a maximum and then decreasing to zero. We compare this
with analytic results obtained for an atom illuminated by a superposition of
Gaussian-Laguerre modes which possess no angular momentum, in the limit of no
recoil.
| [
{
"version": "v1",
"created": "Sun, 2 Feb 1997 18:15:19 GMT"
},
{
"version": "v2",
"created": "Mon, 17 Feb 1997 11:31:51 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Twamley",
"J.",
"",
"Imperial College, London, UK"
]
] |
quant-ph/9702009 | null | Won Young Hwang and In Gyu Koh (KAIST) and Yeong Deok Han (Woosuk
University) | Quantum Cryptography without Public Announcement of Bases | 4 pages | Phys.Lett. A244 (1998) 489-494 | 10.1016/S0375-9601(98)00358-2 | null | quant-ph | null | This paper provides a simple variation of the basic ideas of the BB84 quantum
cryptographic scheme leading to a method of key expansion. A secure random
sequence (the bases sequence) determines the encoding bases in a proposed
scheme. Using the bases sequence repeatedly is proven to be safe by quantum
mechanical laws.
| [
{
"version": "v1",
"created": "Mon, 3 Feb 1997 12:45:51 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Feb 1997 13:04:40 GMT"
},
{
"version": "v3",
"created": "Thu, 6 Feb 1997 14:50:09 GMT"
},
{
"version": "v4",
"created": "Sun, 11 May 1997 12:31:03 GMT"
},
{
"version": "v5",
"created": "Tue, 13 May 1997 02:40:20 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Hwang",
"Won Young",
"",
"KAIST"
],
[
"Koh",
"In Gyu",
"",
"KAIST"
],
[
"Han",
"Yeong Deok",
"",
"Woosuk\n University"
]
] |
quant-ph/9702010 | A. G. Karavayev | A.G. Karavayev | Trajectory-coherent states and the Heisenberg's uncertainty relation | 6 pages LaTex,no figures | null | null | null | quant-ph | null | In this paper we investigate the problem of minimization the Heisenberg's
uncertainty relation by the trajectory-coherent states. The conditions of
minimization for Hamiltonian and trajectory are obtained. We show that the
trajectory-coherent states minimize the Heisenberg's uncertainty relation for
special Cauchy problem for the Schr\"{o}dinger equation only.
| [
{
"version": "v1",
"created": "Mon, 3 Feb 1997 11:40:37 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Karavayev",
"A. G.",
""
]
] |
quant-ph/9702011 | Joy Christian | Jeeva Anandan, Joy Christian, and Kazimir Wanelik (Oxford) | Resource Letter GPP-1: Geometric Phases in Physics | 13 pages (TeX); some new references added | Am.J.Phys. 65 (1997) 180 | 10.1119/1.18570 | null | quant-ph hep-th | null | This Resource Letter provides a guide to the literature on the geometric
angles and phases in classical and quantum physics. Journal articles and books
are cited for the following topics: anticipations of the geometric phase,
foundational derivations and formulations, books and review articles on the
subject, and theoretical and experimental elaborations and applications.
| [
{
"version": "v1",
"created": "Tue, 4 Feb 1997 12:02:31 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Mar 1997 20:12:32 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Anandan",
"Jeeva",
"",
"Oxford"
],
[
"Christian",
"Joy",
"",
"Oxford"
],
[
"Wanelik",
"Kazimir",
"",
"Oxford"
]
] |
quant-ph/9702012 | Joy Christian | Joy Christian (Oxford) | The Plight of `I Am' | 4 pages (tex); uses mtexsis.tex (included) | Metaphysical Review, vol. 3, no. 1, July 1996 | null | null | quant-ph | null | This is a short metaphysical fable accentuating the conceptual difficulties
involved, and succinctly criticizing the approaches pursued since the inception
of quantum theory, in dealing with what is known collectively as `the
measurement problem.' It includes some landmark references, and has appeared in
the special issue of Metaphysical Review dedicated to Descartes on his 400th
birthday: Metaphysical Review, vol. 3, no. 1, July 1996.
| [
{
"version": "v1",
"created": "Tue, 4 Feb 1997 12:03:41 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Christian",
"Joy",
"",
"Oxford"
]
] |
quant-ph/9702013 | Helmut Kroger | H. Kr\"oger | Proposal for an experiment to measure the Hausdorff dimension of quantum
mechanical trajectories | 35 pages, LaTeX + 27 figures, ps and gif | Phys.Rev. A55 (1997) 951 | 10.1103/PhysRevA.55.951 | LAVAL-PHY-4-95 | quant-ph | null | We make a proposal for a Gedanken experiment, based on the Aharonov-Bohm
effect, how to measure in principle the zig-zagness of the trajectory of
propagation (abberation from its classical trajectory) of a massive particle in
quantum mechanics. Experiment I is conceived to show that contributions from
quantum paths abberating from the classical trajectory are directly observable.
Experiment II is conceived to measure average length, scaling behavior and
critical exponent (Hausdorff dimension) of quantum mechanical paths.
| [
{
"version": "v1",
"created": "Tue, 4 Feb 1997 18:28:26 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Kröger",
"H.",
""
]
] |
quant-ph/9702014 | Sher Alam | S. Alam (KEK) and C. Bentley | The Relevant Operators for the generalized time-dependent m-photon
Jaynes-Cummings Hamiltonian | 12 pages, RevTex | Prog.Theor.Phys. 98 (1997) 351-357 | 10.1143/PTP.98.351 | KEK preprint KEK-TH-510 | quant-ph | null | The m-photon Jaynes-Cummings Hamiltonian is a natural generalization of the
much studied Jaynes-Cummings Hamiltonian. In this short note we give the
relevant operators for the time-dependent generalized m-photon Jaynes-Cummings
Hamiltonian. The dynamical equations for these operators are also given. These
operators are needed and indeed are the basic building blocks for performing
calculations in the context of the Maximum Entropy Formalism.
| [
{
"version": "v1",
"created": "Wed, 5 Feb 1997 05:52:01 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Alam",
"S.",
"",
"KEK"
],
[
"Bentley",
"C.",
""
]
] |
quant-ph/9702015 | Chi-Sheng Niu | Robert B. Griffiths, Chi-Sheng Niu | Optimal Eavesdropping in Quantum Cryptography. II. Quantum Circuit | 7 pages, 1 figure, Latex, the second part of quant-ph/9701039 | null | 10.1103/PhysRevA.56.1173 | null | quant-ph | null | It is shown that the optimum strategy of the eavesdropper, as described in
the preceding paper, can be expressed in terms of a quantum circuit in a way
which makes it obvious why certain parameters take on particular values, and
why obtaining information in one basis gives rise to noise in the conjugate
basis.
| [
{
"version": "v1",
"created": "Thu, 6 Feb 1997 00:00:21 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Griffiths",
"Robert B.",
""
],
[
"Niu",
"Chi-Sheng",
""
]
] |
quant-ph/9702016 | Alexander V. Gorokhov | Alexander V. Gorokhov, Elena V. Rogacheva, and Alexander V. Shiryaev
(Samara State University, Samara, Russia) | Regular and Chaotic Coherent State Dynamics of Several Quantum Optical
Models | 15 pages, 15 Postscript Figures | null | null | null | quant-ph | null | The coherent state representations of the group $G = W_1 \otimes G_0$ (where
$G_0 = SU(2), SU(1,1)$) are used in computer simulation of the dynamics of
single two-level atom $(G_0 = SU(2))$ interacting with a quantized photon
cavity mode - the Jaynes - Cummings model (JCM) without the rotating wave
approximation and, in general, nonlinear in photon variables). The second case
(hyperbolic Jaynes - Cummings model (HJCM), $G_0 = SU(1,1))$ corresponds to the
quantum dynamics of quadratic nonlinear coupled oscillators (the parametric
resonance on double field frequency and a three - wave parametric processes of
nonlinear optics). Quasiclassical dynamical equations for parameters of
approximately factorizable coherent states for these models are derived and
regimes of motion for "atom" and field variables are analyzed.
| [
{
"version": "v1",
"created": "Thu, 6 Feb 1997 09:31:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gorokhov",
"Alexander V.",
"",
"Samara State University, Samara, Russia"
],
[
"Rogacheva",
"Elena V.",
"",
"Samara State University, Samara, Russia"
],
[
"Shiryaev",
"Alexander V.",
"",
"Samara State University, Samara, Russia"
]
] |
quant-ph/9702017 | Costas Efthimiou | Costas Efthimiou and Donald Spector | Shape Invariance in the Calogero and Calogero-Sutherland Models | Latex file, 23 pages, no pictures | null | 10.1103/PhysRevA.56.208 | TAUP 2363-96, NIKHEF 96-034, HWS 9617 | quant-ph cond-mat hep-th | null | We show that the Calogero and Calogero-Sutherland models possess an N-body
generalization of shape invariance. We obtain the operator representation that
gives rise to this result, and discuss the implications of this result,
including the possibility of solving these models using algebraic methods based
on this shape invariance. Our representation gives us a natural way to
construct supersymmetric generalizations of these models, which are interesting
both in their own right and for the insights they offer in connection with the
exact solubility of these models.
| [
{
"version": "v1",
"created": "Thu, 6 Feb 1997 15:37:31 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Efthimiou",
"Costas",
""
],
[
"Spector",
"Donald",
""
]
] |
quant-ph/9702018 | Arkadiusz Jadczyk | Ph. Blanchard and A. Jadczyk | Time and Events | Talk presented at the conference Quantum Structures '96, Berlin, July
29-August 3, TUB, by the second named Author; 7 pages Latex, 1 latexcad
figure, 1 postscript figure; Postscript file also available at
http://www.ift.uni.wroc.pl/~ajad/blaja97a.ps | Int.J.Theor.Phys.37:227-233,1998 | 10.1023/A:1026654431713 | BiBoS 754/1/97 | quant-ph | null | Time plays a special role in Standard Quantum Theory. The concept of time
observable causes many controversies there. In Event Enhanced Quantum Theory
(in short: EEQT) Schroedinger's differential equation is replaced by a em
piecewise deterministic algorithm} that describes also the timing of events.
This allows us to revisit the problem of time of arrival in quantum theory.
| [
{
"version": "v1",
"created": "Thu, 6 Feb 1997 16:09:39 GMT"
}
] | 2011-04-15T00:00:00 | [
[
"Blanchard",
"Ph.",
""
],
[
"Jadczyk",
"A.",
""
]
] |
quant-ph/9702019 | Arkadiusz Jadczyk | Ph. Blanchard and A. Jadczyk | Time of Arrival in Event Enhanced Quantum Theory | Talk presented at theXXI International Colloquium on Group
Theoretical Methods in Physics 15-20 July 1996, Goslar, by the second named
author; 5 pages Latex, 2 postscript figures; Postscript file available under
URL http://www.ift.uni.wroc.pl/~ajad/blaja97b.ps | null | null | null | quant-ph | null | The new solution to the problem of time of arrival in quantum theory is
presented herein. It allows for computer simulation of particle counters and it
implies Born's interpretation. It also suggests new experiments that can answer
the question: can a quantum particle detect a detector without being detected?
| [
{
"version": "v1",
"created": "Thu, 6 Feb 1997 16:25:09 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Blanchard",
"Ph.",
""
],
[
"Jadczyk",
"A.",
""
]
] |
quant-ph/9702020 | Fabrizio | Giovanni Costantini, Fabrizio Smeraldi | A Generalization of Deutsch's Example | 17 pages, LaTeX, 5 PostScript figures | null | null | null | quant-ph | null | Quantum parallelism is the main feature of quantum computation. In 1985 D.
Deutsch showed that a single quantum computation may be sufficient to state
whether a two-valued function of a two-valued variable is constant or not.
Though the generalized problem with unconstrained domain and range size admits
no deterministic quantum solution, a fully probabilistic quantum algorithm is
presented in which quantum parallelism is harnessed to achieve a quicker
exploration of the domain with respect to the classical ``sampling'' strategy.
| [
{
"version": "v1",
"created": "Fri, 7 Feb 1997 09:55:23 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Costantini",
"Giovanni",
""
],
[
"Smeraldi",
"Fabrizio",
""
]
] |
quant-ph/9702021 | Paul Benioff | Paul Benioff (Physics Division, Argonne National Laboratory, Argonne
IL) | The Landauer Resistance and Band Spectra for the Counting Quantum Turing
Machine | 19 pages Latex, elsart.sty file included, 12 postscript figures,
Submitted to PhysComp96 for publication in Physica-D | Physica D120 (1998) 12-29 | 10.1016/S0167-2789(98)00041-4 | null | quant-ph | null | The generalized counting quantum Turing machine (GCQTM) is a machine which,
for any N, enumerates the first $2^{N}$ integers in succession as binary
strings. The generalization consists of associating a potential with read-1
steps only. The Landauer Resistance (LR) and band spectra were determined for
the tight binding Hamiltonians associated with the GCQTM for energies both
above and below the potential height. For parameters and potentials in the
electron region, the LR fluctuates rapidly between very high and very low
values as a function of momentum. The rapidity and extent of the fluctuations
increases rapidly with increasing N. For N=18, the largest value considered,
the LR shows good transmission probability as a function of momentum with
numerous holes of very high LR values present. This is true for energies above
and below the potential height. It is suggested that the main features of the
LR can be explained by coherent superposition of the component waves reflected
from or transmitted through the $2^{N-1}$ potentials in the distribution. If
this explanation is correct, it provides a dramatic illustration of the effects
of quantum nonlocality.
| [
{
"version": "v1",
"created": "Fri, 7 Feb 1997 15:33:51 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Benioff",
"Paul",
"",
"Physics Division, Argonne National Laboratory, Argonne\n IL"
]
] |
quant-ph/9702022 | null | P. Exner and P. \v{S}eba | Resonance statistics in a microwave cavity with a thin antenna | 10 pages LaTeX source file with one ps figure; to appear in
Phys.Lett. A | Phys.Lett. A228 (1997) 146-150 | 10.1016/S0375-9601(97)00120-5 | null | quant-ph chao-dyn cond-mat nlin.CD | null | We propose a model for scattering in a flat resonator with a thin antenna.
The results are applied to rectangular microwave cavities. We compute the
resonance spacing distribution and show that it agrees well with experimental
data provided the antenna radius is much smaller than wavelengths of the
resonance wavefunctions.
| [
{
"version": "v1",
"created": "Fri, 7 Feb 1997 15:24:22 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Exner",
"P.",
""
],
[
"Šeba",
"P.",
""
]
] |
quant-ph/9702023 | Werner Hofer | W. A. Hofer (TU Wien) | Non--locality of particle spin: a consequence of interaction energy? | 4 pages (ReVTeX, twocolumn) and 3 figures (eps) | null | null | MW-97-01 | quant-ph | null | Neutron interference measurements with macroscopic beam separation allow to
study the influence of magnetic fields on spin properties. By calculating the
interaction energy with a dynamic and deterministic model, we are able to
establish that the phase shift on one component of the neutron beam is linear
with magnetic intensity, and equally, that interaction energy as well as phase
shifts do not depend on the orientation of the magnetic field. The theoretical
treatment allows the conclusion that the non-local properties of particle spin
derive from the classical equation for interaction energy and the fact, that
interaction energy does not depend on magnetic field orientation. Additionally,
it can be established that the 4 pi symmetry of spinors in this case depends on
the scaling of magnetic fields.
| [
{
"version": "v1",
"created": "Sat, 8 Feb 1997 12:11:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hofer",
"W. A.",
"",
"TU Wien"
]
] |
quant-ph/9702024 | Silviu Olariu | Silviu Olariu (Bucharest, Romania) | Aharonov-Bohm interference in the presence of metallic mesoscopic
cylinders | 15 pages, 5 Postscript figures | null | 10.1103/PhysRevA.55.94 | null | quant-ph | null | This work studies the interference of electrons in the presence of a line of
magnetic flux surrounded by a normal-conducting mesoscopic cylinder at low
temperature. It is found that, while there is a supplementary phase
contribution from each electron of the mesoscopic cylinder, the sum of these
individual supplementary phases is equal to zero, so that the presence of a
normal-conducting mesoscopic ring at low temperature does not change the
Aharonov-Bohm interference pattern of the incident electron. It is shown that
it is not possible to ascertain by experimental observation that the shielding
electrons have responded to the field of an incident electron, and at the same
time to preserve the interference pattern of the incident electron. It is also
shown that the measuring of the transient magnetic field in the region between
the two paths of an electron interference experiment with an accuracy at least
equal to the magnetic field of the incident electron generates a phase
uncertainty which destroys the interference pattern.
| [
{
"version": "v1",
"created": "Mon, 10 Feb 1997 05:31:19 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Olariu",
"Silviu",
"",
"Bucharest, Romania"
]
] |
quant-ph/9702025 | Silviu Olariu | Silviu Olariu (Bucharest, Romania) | Quantum Interference of Polarized Electrons in the Presence of Magnetic
Strings | 14 pages | null | null | null | quant-ph | null | This work analyzes the effects of shielding on the Aharonov-Bohm scattering
of electrons endowed with spin. The interaction of polarized electrons with
bare and shielded magnetic strings is studied with the aid of the Dirac
equation. It is found that the difference between the amplitudes for the
scattering by bare and shielded strings of incident wave packets of width
$\delta$ and impact parameter $d$ is proportional to $\exp(-d^2/2\delta^2)$.
| [
{
"version": "v1",
"created": "Mon, 10 Feb 1997 05:32:25 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Olariu",
"Silviu",
"",
"Bucharest, Romania"
]
] |
quant-ph/9702026 | Yu Shi | Yu Shi | Spontaneous Symmetry Breaking, Off-diagonal Long-range Order, and
Nucleation of Quantum State | 26 pages, Latex, a revised version | null | null | null | quant-ph cond-mat | null | Spontaneous symmetry breaking originats in quantum mechanical measurement of
the relevant observable defining the physical situation, order parameter is the
average of this observable. A modification is made on the random-phase
postulate validating the ensemble description. Off-diagonal long-range order,
macroscopic wavefunction and interference effects in many-particle systems
present when there is a so-called nucleation of quantum state, which is
proposed to be the origin of spontaneous gauge symmetry breaking, for which
nonconservation of particle number N is not essential. The approach based on
nonvanishing expectation of the field operator, $<\hat{\psi}(\vec{r})>$, is
only a coherent-state approximation in thermodynamic limit. When $N \to
\infty$, this approach is equivalent, but $<\hat{\psi}(\vec{r})>$ is not the
macroscopic wavefunction.
| [
{
"version": "v1",
"created": "Tue, 11 Feb 1997 08:23:23 GMT"
},
{
"version": "v2",
"created": "Wed, 26 Feb 1997 13:39:20 GMT"
},
{
"version": "v3",
"created": "Sat, 22 Mar 1997 18:12:04 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Shi",
"Yu",
""
]
] |
quant-ph/9702027 | Martin Plenio | V. Vedral, M.B. Plenio, M.A. Rippin, P. L. Knight (Imperial College
London) | Quantifying Entanglement | 4 pages twocolumn, one figure | Phys.Rev.Lett.78:2275-2279,1997 | 10.1103/PhysRevLett.78.2275 | null | quant-ph | null | We present conditions every measure of entanglement has to satisfy and
construct a whole class of 'good' entanglement measures. The generalization of
our class of entanglement measures to more than two particles is
straightforward. We present a measure which has a statistical operational basis
that might enable experimental determination of the quantitative degree of
entanglement.
| [
{
"version": "v1",
"created": "Tue, 11 Feb 1997 14:31:20 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Vedral",
"V.",
"",
"Imperial College\n London"
],
[
"Plenio",
"M. B.",
"",
"Imperial College\n London"
],
[
"Rippin",
"M. A.",
"",
"Imperial College\n London"
],
[
"Knight",
"P. L.",
"",
"Imperial College\n London"
]
] |
quant-ph/9702028 | Peter Hoyer | Peter Hoyer (Odense University) | Efficient Quantum Transforms | 30 pages, LaTeX2e, 7 figures included | null | null | null | quant-ph | null | Quantum mechanics requires the operation of quantum computers to be unitary,
and thus makes it important to have general techniques for developing fast
quantum algorithms for computing unitary transforms. A quantum routine for
computing a generalized Kronecker product is given. Applications include
re-development of the networks for computing the Walsh-Hadamard and the quantum
Fourier transform. New networks for two wavelet transforms are given. Quantum
computation of Fourier transforms for non-Abelian groups is defined. A slightly
relaxed definition is shown to simplify the analysis and the networks that
computes the transforms. Efficient networks for computing such transforms for a
class of metacyclic groups are introduced. A novel network for computing a
Fourier transform for a group used in quantum error-correction is also given.
| [
{
"version": "v1",
"created": "Wed, 12 Feb 1997 00:52:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hoyer",
"Peter",
"",
"Odense University"
]
] |
quant-ph/9702029 | Daniel Gottesman | Daniel Gottesman | A Theory of Fault-Tolerant Quantum Computation | 30 pages, REVTeX, universal swapping operation added to allow
universal computation on any stabilizer code | Phys.Rev.A57:127,1998 | 10.1103/PhysRevA.57.127 | CALT-68-2100, QUIC-97-004 | quant-ph | null | In order to use quantum error-correcting codes to actually improve the
performance of a quantum computer, it is necessary to be able to perform
operations fault-tolerantly on encoded states. I present a general theory of
fault-tolerant operations based on symmetries of the code stabilizer. This
allows a straightforward determination of which operations can be performed
fault-tolerantly on a given code. I demonstrate that fault-tolerant universal
computation is possible for any stabilizer code. I discuss a number of examples
in more detail, including the five-qubit code.
| [
{
"version": "v1",
"created": "Wed, 12 Feb 1997 00:48:43 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Feb 1997 01:39:22 GMT"
}
] | 2011-07-19T00:00:00 | [
[
"Gottesman",
"Daniel",
""
]
] |
quant-ph/9702030 | Reinhold Walser | Peter Zoller and C. W.Gardiner, (University of Innsbruck, Austria and
Victoria University, Wellington, New Zealand) | Quantum Noise in Quantum Optics: the Stochastic Schr\"odinger Equation | 57 pages (LaTeX 2.09) including 11 figures (.ps) | null | null | null | quant-ph | null | Lecture Notes for the Les Houches Summer School LXIII on Quantum Fluctuations
in July 1995 to appear in Elsevier Science Publishers B.V. 1997, edited by E.
Giacobino and S. Reynaud.
| [
{
"version": "v1",
"created": "Wed, 12 Feb 1997 17:02:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zoller",
"Peter",
""
],
[
"Gardiner",
"C. W.",
""
]
] |
quant-ph/9702031 | Nicolas Cerf | Nicolas J. Cerf (Caltech), Richard Cleve (Univ. of Calgary) | Information-theoretic interpretation of quantum error-correcting codes | 14 pages RevTeX, 8 Postscript figures. Added appendix. To appear in
Phys. Rev. A | Phys.Rev.A56:1721,1997 | 10.1103/PhysRevA.56.1721 | KRL MAP-209 | quant-ph | null | Quantum error-correcting codes are analyzed from an information-theoretic
perspective centered on quantum conditional and mutual entropies. This approach
parallels the description of classical error correction in Shannon theory,
while clarifying the differences between classical and quantum codes. More
specifically, it is shown how quantum information theory accounts for the fact
that "redundant" information can be distributed over quantum bits even though
this does not violate the quantum "no-cloning" theorem. Such a remarkable
feature, which has no counterpart for classical codes, is related to the
property that the ternary mutual entropy vanishes for a tripartite system in a
pure state. This information-theoretic description of quantum coding is used to
derive the quantum analogue of the Singleton bound on the number of logical
bits that can be preserved by a code of fixed length which can recover a given
number of errors.
| [
{
"version": "v1",
"created": "Thu, 13 Feb 1997 22:50:21 GMT"
},
{
"version": "v2",
"created": "Sun, 22 Jun 1997 01:11:10 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Cerf",
"Nicolas J.",
"",
"Caltech"
],
[
"Cleve",
"Richard",
"",
"Univ. of Calgary"
]
] |
quant-ph/9702032 | Paul Tapster | J G Rarity, P R Tapster, R Loudon | Non-classical interference between independent sources | 6 pages, RevTeX, 4 figures | null | null | null | quant-ph | null | When a one-photon state is mixed with a (separate) weak coherent state at a
beamsplitter the probability for detecting one photon in each beamsplitter
output approaches zero due to destructive interference. We demonstrate this
non-classical interference effect using pulse-gated single photons and weak
mode-locked laser pulses.
| [
{
"version": "v1",
"created": "Fri, 14 Feb 1997 11:03:57 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Feb 1997 11:24:02 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Rarity",
"J G",
""
],
[
"Tapster",
"P R",
""
],
[
"Loudon",
"R",
""
]
] |
quant-ph/9702033 | Chau Hoi Fung | H. F. Chau | Five Quantum Register Error Correction Code For Higher Spin Systems | Revised version, to appear in Phys.Rev.A (Rapid Communications). 4
pages in Revtex 3.1, using amssymb.sty | null | 10.1103/PhysRevA.56.R1 | HKUPHYS-HFC-02 | quant-ph | null | I construct a quantum error correction code (QECC) in higher spin systems
using the idea of multiplicative group character. Each $N$ state quantum
particle is encoded as five $N$ state quantum registers. By doing so, this code
can correct any quantum error arising from any one of the five quantum
registers. This code generalizes the well-known five qubit perfect code in
spin-1/2 systems and is shown to be optimal for higher spin systems. I also
report a simple algorithm for encoding. The importance of multiplicative group
character in constructing QECCs will be addressed.
| [
{
"version": "v1",
"created": "Sun, 16 Feb 1997 09:02:05 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Feb 1997 10:02:54 GMT"
},
{
"version": "v3",
"created": "Mon, 19 May 1997 13:56:01 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Chau",
"H. F.",
""
]
] |
quant-ph/9702034 | Davit Saakian | A.E. Allahverdyan, D.B. Saakian | Converse coding theorems for quantums source and noisy channel | 11 pages, LaTex, no figures | null | null | null | quant-ph | null | The weak converse coding theorems have been proved for the quantum source and
channel. The results give the lower bound for capacity of source and the upper
bound for capacity of channel. The monotonicity of mutual quantum information
have also been proved. PACS numbers: 03.65.Bz
| [
{
"version": "v1",
"created": "Tue, 18 Feb 1997 10:52:18 GMT"
},
{
"version": "v2",
"created": "Wed, 21 May 1997 11:14:49 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Allahverdyan",
"A. E.",
""
],
[
"Saakian",
"D. B.",
""
]
] |
quant-ph/9702035 | null | V.I. Man'ko and R.V. Mendes | Time-Dependent Invariants for Dirac Equation and Newton-Wigner Position
Operator | LATEX,21 pages,submitted to Physica Scripta | null | 10.1088/0031-8949/56/5/001 | null | quant-ph | null | For Dirac equation, operator-invariants containing explicit time-dependence
in parallel to known time-dependent invariants of nonrelativistic Schr\"odinger
equation are introduced and discussed. As an example, a free Dirac particle is
considered and new invariants are constructed for it. The integral of motion,
which is initial Newton-Wigner position operator, is obtained explicitly for a
free Dirac particle. For such particle with kick modeled by delta-function of
time, the time-depending integral, which has physical meaning of initial
momentum, is found.
| [
{
"version": "v1",
"created": "Tue, 18 Feb 1997 10:53:03 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Man'ko",
"V. I.",
""
],
[
"Mendes",
"R. V.",
""
]
] |
quant-ph/9702036 | Steven van Enk | S.J. van Enk, J.I. Cirac, P. Zoller | Ideal Quantum Communication over Noisy Channels: a Quantum Optical
Implementation | RevTeX, 5 pages, 2 eps figures included | Phys.Rev.Lett.78:4293-4296,1997 | 10.1103/PhysRevLett.78.4293 | null | quant-ph | null | We consider transmission of an (unknown) quantum state between two distant
atoms via photons. Based on a quantum-optical realistic model, we define a
noisy quantum channel which includes systematic errors as well as errors due to
coupling to the environment. We present a protocol that allows one to
accomplish ideal transmission by repeating the transfer operation as many times
as needed.
| [
{
"version": "v1",
"created": "Tue, 18 Feb 1997 14:19:19 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Feb 1997 08:41:23 GMT"
},
{
"version": "v3",
"created": "Thu, 20 Feb 1997 16:02:16 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"van Enk",
"S. J.",
""
],
[
"Cirac",
"J. I.",
""
],
[
"Zoller",
"P.",
""
]
] |
quant-ph/9702037 | null | Won Young Hwang and In Gyu Koh (KAIST) and Yeong Deok Han (Woosuk
University) | The quantum cryptography and the unambiguous measurement of quantum
nonorthogonal states | withdrawal | null | null | null | quant-ph | null | We discuss the unambiguous measurement of quantum nonorthogonal states in
connection with the quantum cryptography. We show that checking a ratio of null
one to signal is essential in detecting a certain kind of eavesdropping in the
case of two nonorthogonal states quantum cryptography. We prove that it is not
needed in the case of the four states quantum cryptography.
| [
{
"version": "v1",
"created": "Wed, 19 Feb 1997 02:38:28 GMT"
},
{
"version": "v2",
"created": "Tue, 29 Apr 1997 13:17:19 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Hwang",
"Won Young",
"",
"KAIST"
],
[
"Koh",
"In Gyu",
"",
"KAIST"
],
[
"Han",
"Yeong Deok",
"",
"Woosuk\n University"
]
] |
quant-ph/9702038 | Wayne M. Itano | W. M. Itano, C. Monroe, D. M. Meekhof, D. Leibfried, B. E. King and D.
J. Wineland | Quantum harmonic oscillator state synthesis and analysis | 13 pages, LaTeX2e, special style file spie.sty included, 11 eps
figures included using epsfig, graphicx, subfigure, floatflt macros. To
appear in Proc. Conf. on Atom Optics, San Jose, CA, Feb. 1997, edited by M.
G. Prentiss and W. D. Phillips, SPIE Proc. # 2995 | null | 10.1117/12.273771 | null | quant-ph | null | Experiments are described in which a single, harmonically bound, beryllium
ion in a Paul trap is put into Fock, thermal, coherent, squeezed, and
Schroedinger cat states. Experimental determinations of the density matrix and
the Wigner function are described. A simple calculation of the decoherence of a
superposition of coherent states due to an external electric field is given.
| [
{
"version": "v1",
"created": "Wed, 19 Feb 1997 21:17:05 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Itano",
"W. M.",
""
],
[
"Monroe",
"C.",
""
],
[
"Meekhof",
"D. M.",
""
],
[
"Leibfried",
"D.",
""
],
[
"King",
"B. E.",
""
],
[
"Wineland",
"D. J.",
""
]
] |
quant-ph/9702039 | Haiqing Wei | Haiqing Wei and Xin Xue | Tailoring Many-Body Interactions to Solve Hard Combinatorial Problems | Latex 7 pages, 3 ps figures | null | null | null | quant-ph | null | A quantum machine consisting of interacting linear clusters of atoms is
proposed for the 3SAT problem. Each cluster with two relevant states of
collective motion can be used to register a Boolean variable. Given any 3SAT
Boolean formula the interactions among the clusters can be so tailored that the
ground state(s) (possibly degenerate) of the whole system encodes the
satisfying truth assignment(s) for it. This relates the 3SAT problem to the
dynamics of the properly designed glass system.
| [
{
"version": "v1",
"created": "Thu, 20 Feb 1997 14:57:04 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Feb 1997 18:00:28 GMT"
},
{
"version": "v3",
"created": "Mon, 7 Jul 1997 19:09:14 GMT"
},
{
"version": "v4",
"created": "Tue, 8 Jul 1997 01:56:15 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Wei",
"Haiqing",
""
],
[
"Xue",
"Xin",
""
]
] |
quant-ph/9702040 | null | Salvatore De Martino, Silvio De Siena, Fabrizio Illuminati | Theory of controlled quantum dynamics | LaTeX, A4wide, 28 pages, no figures. To appear in J. Phys. A: Math.
Gen., April 1997 | J.Phys.A30:4117-4132,1997 | 10.1088/0305-4470/30/11/035 | null | quant-ph | null | We introduce a general formalism, based on the stochastic formulation of
quantum mechanics, to obtain localized quasi-classical wave packets as
dynamically controlled systems, for arbitrary anharmonic potentials. The
control is in general linear, and it amounts to introduce additional quadratic
and linear time-dependent terms to the given potential. In this way one can
construct for general systems either coherent packets moving with constant
dispersion, or dynamically squeezed packets whose spreading remains bounded for
all times. In the standard operatorial framework our scheme corresponds to a
suitable generalization of the displacement and scaling operators that generate
the coherent and squeezed states of the harmonic oscillator.
| [
{
"version": "v1",
"created": "Thu, 20 Feb 1997 17:29:04 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"De Martino",
"Salvatore",
""
],
[
"De Siena",
"Silvio",
""
],
[
"Illuminati",
"Fabrizio",
""
]
] |
quant-ph/9702041 | Haiqing Wei | Xin Xue and Haiqing Wei | Superconductive Static Quantum Logic | Latex 4 pages, 4 ps figures | null | null | null | quant-ph | null | Superconducting rings with exactly $\Phi _0/2$ magnetic flux threading are
analogous of Ising spins having two degenerate states which can be used to
store binary information. When brought close these rings interact by means of
magnetic coupling. If the interactions are properly tailored, a system of such
superconducting rings can accomplish static quantum logic in the sense that the
states of the rings interpreted as Boolean variables satisfy the desired logic
relations when and only when the whole system is in the ground state. Such
static logic is essential to carry out the static quantum computation [1,2].
| [
{
"version": "v1",
"created": "Thu, 20 Feb 1997 17:45:56 GMT"
},
{
"version": "v2",
"created": "Tue, 8 Jul 1997 02:50:17 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Xue",
"Xin",
""
],
[
"Wei",
"Haiqing",
""
]
] |
quant-ph/9702042 | Maria Vanessa Jimenez de la Vega | A. Cabo, J. L. Lucio and H. Mercado | On Scale Invariance and Anomalies in Quantum Mechanics | 15 pp in latex, no figures | Am.J.Phys.66:240,1998 | 10.1119/1.18852 | null | quant-ph | null | We re-consider the quantum mechanics of scale invariant potentials in two
dimensions. The breaking of scale invariance by quantum effects is analyzed by
the explicit evaluation of the phase shift and the self-adjoint extension
method. We argue that the breaking of scale invariance reported in the
literature for the $\delta$(r) potential, is an example of explicit and not an
anomaly or quantum mechanical symmetry breaking.
| [
{
"version": "v1",
"created": "Thu, 20 Feb 1997 18:53:49 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Cabo",
"A.",
""
],
[
"Lucio",
"J. L.",
""
],
[
"Mercado",
"H.",
""
]
] |
quant-ph/9702043 | Piotr Rozmej | R. Arvieu, P. Rozmej and W. Berej | Time dependent partial waves and vortex rings in the dynamics of wave
packets | 10 pages, LaTeX, 6 postscript figures, submitted to J. Phys. A: Math.
Gen | J.Phys.A30:5381-5392,1997 | 10.1088/0305-4470/30/15/023 | null | quant-ph | null | We have found a new class of time dependent partial waves which are solutions
of time dependent Schr\"odinger equation for three dimensional harmonic
oscillator. We also showed the decomposition of coherent states of harmonic
oscillator into these partial waves. This decomposition appears perticularly
convenient for a description of the dynamics of a wave packet representing a
particle with spin when the spin--orbit interaction is present in the
hamiltonian. An example of an evolution of a localized wave packet into a torus
and backwards, for a particular initial conditions is analysed in analytical
terms and shown with a computer graphics.
| [
{
"version": "v1",
"created": "Fri, 21 Feb 1997 08:10:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Arvieu",
"R.",
""
],
[
"Rozmej",
"P.",
""
],
[
"Berej",
"W.",
""
]
] |
quant-ph/9702044 | Piotr Rozmej | P. Rozmej and R. Arvieu and W. Berej | New mechanism of collapse and revival in wave packet dynamics due to
spin-orbit interaction | 10 pages, LaTeX, 7 PS figures (in 6 separate files), to appear in
Acta Phys. Polon. (Invited lecture at XXXI Zakopane School of Physics,
Zakopane, Poland, September 3-11, 1996) | Acta Phys.Polon.B28:243-255,1997 | null | null | quant-ph | null | The article discusses the properties of time evolution of wave packets in a
few systems. Dynamics of wave packet motion for Rydberg atoms with the
hierarchy of collapses and revivals is briefly reviewed. The main part of the
paper focuses on the new mechanism of quantum reccurrences in wave packet
dynamics. This mechanism can occur (in principle) in any physical system with
strong enough spin-orbit interaction. We discuss here the SPIN_ORBIT PENDULUM
effect that consists in different motions of subpackets possessing different
spin fields and results in oscillations of a fraction of average angular
momentum between spin and ordinary subspaces. The evolution of localized wave
packet into toroidal objects and backwards (for other class of initial
conditions) is also subject to discussion.
| [
{
"version": "v1",
"created": "Fri, 21 Feb 1997 12:52:04 GMT"
}
] | 2011-04-15T00:00:00 | [
[
"Rozmej",
"P.",
""
],
[
"Arvieu",
"R.",
""
],
[
"Berej",
"W.",
""
]
] |
quant-ph/9702045 | Paulo Laerte Natti S. | P.R.I. Tommasini (Inst. for Theoretical Atomic and Molecular Physics),
P.L. Natti (Univ. Estadual de Londrina), E.R. Takano Natti (Univ. do Norte do
Parana), A.F.R. de Toledo Piza and C.-Y. Lin (Univ. de Sao Paulo) | Exact Solution Versus Gaussian Approximation for a Non-Ideal Bose Gas in
One-Dimension | 21 pages, added references, corrected typos, submitted to Physica A | null | null | IFUSP/P-1259 | quant-ph | null | We investigate ground-state and excitation spectrum of a system of
non-relativistic bosons in one-dimension interacting through repulsive,
two-body contact interactions in a self-consistent Gaussian mean-field
approximation. The method consists in writing the variationally determined
density operator as the most general Gaussian functional of the quantized field
operators. There are mainly two advantages in working with one-dimension.
First, the existence of an exact solution for the ground-state and excitation
energies. Second, neither in the perturbative results nor in the Gaussian
approximation itself we do not have to deal with the three-dimensional
patologies of the contact interaction . So that this scheme provides a clear
comparison between these three different results.
| [
{
"version": "v1",
"created": "Fri, 21 Feb 1997 21:45:15 GMT"
},
{
"version": "v2",
"created": "Sat, 30 Jan 1999 21:49:20 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Tommasini",
"P. R. I.",
"",
"Inst. for Theoretical Atomic and Molecular Physics"
],
[
"Natti",
"P. L.",
"",
"Univ. Estadual de Londrina"
],
[
"Natti",
"E. R. Takano",
"",
"Univ. do Norte do\n Parana"
],
[
"Piza",
"A. F. R. de Toledo",
"",
"Univ. de Sao Paulo"
],
[
"Lin",
"C. -Y.",
"",
"Univ. de Sao Paulo"
]
] |
quant-ph/9702046 | Haiqing Wei | Haiqing Wei, Xin Xue | Static Quantum Computation | 8 pages, 3 ps figures | null | null | null | quant-ph | null | Tailoring many-body interactions among a proper quantum system endows it with
computing ability by means of static quantum computation in the sense that some
of the physical degrees of freedom can be used to store binary information and
the corresponding binary variables satisfy some given logic relations if and
only if the system is in the ground state. Two theorems are proved showing that
the universal static quantum computer can encode the solutions for any P and NP
problem into its ground state using only polynomial number (in the problem
input size) of logic gates. The second step is to read out the solutions by
relaxing the system. The time complexity is relevant when one tries to read out
the solution by relaxing the system, therefore our model of static quantum
computation provides a new connection between the computational complexity and
the dynamics of a complex system.
| [
{
"version": "v1",
"created": "Sat, 22 Feb 1997 23:29:16 GMT"
},
{
"version": "v2",
"created": "Sun, 1 Mar 1998 02:52:57 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Wei",
"Haiqing",
""
],
[
"Xue",
"Xin",
""
]
] |
quant-ph/9702047 | Holger Lyre | Holger Lyre | Multiple Quantization and the Concept of Information | 7 pages | Int.J.Theor.Phys. 35 (1996) 2219-2225 | null | null | quant-ph | null | The understanding of the meaning of quantization seems to be the main problem
in understanding quantum structures. In this paper first the difference between
quantized particle vs. radiation fields in the formalism of canonical
quantization is discussed. Next von Weizsaecker's concept of ''multiple
quantization'' which leads to an understanding of quantization as an iteration
of probability theory is explained. Finally a connection between quantization
and the idea of a ''general theory of information'' is considered. This brings
together semantic information with the different levels of quantization and
expresses the philosophical attitude of this paper concerning the
interpretation of quantum theory.
| [
{
"version": "v1",
"created": "Mon, 24 Feb 1997 02:12:03 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lyre",
"Holger",
""
]
] |
quant-ph/9702048 | Riccardo Adami | Riccardo Adami and Alessandro Teta | On the Aharonov-Bohm Effect | 15 pages, latex, no figures | Lett.Math.Phys. 43 (1998) 43-53 | null | null | quant-ph | null | Using the theory of self-adjoint extensions, we construct all the possible
hamiltonians describing the non relativistic Aharonov-Bohm effect. In general
the resulting hamiltonians are not rotationally invariant so that the angular
momentum is not a constant of motion. Using an explicit formula for the
resolvent, we describe the spectrum and compute the generalized eigenfunctions
and the scattering amplitude.
| [
{
"version": "v1",
"created": "Tue, 25 Feb 1997 15:13:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Adami",
"Riccardo",
""
],
[
"Teta",
"Alessandro",
""
]
] |
quant-ph/9702049 | Michael Nielsen | Howard Barnum, M. A. Nielsen and Benjamin Schumacher | Information transmission through a noisy quantum channel | 26 pages, REVTEX | null | 10.1103/PhysRevA.57.4153 | null | quant-ph | null | Noisy quantum channels may be used in many information carrying applications.
We show that different applications may result in different channel capacities.
Upper bounds on several of these capacities are proved. These bounds are based
on the coherent information, which plays a role in quantum information theory
analogous to that played by the mutual information in classical information
theory. Many new properties of the coherent information and entanglement
fidelity are proved. Two non-classical features of the coherent information are
demonstrated: the failure of subadditivity, and the failure of the pipelining
inequality. Both properties arise as a consequence of quantum entanglement, and
give quantum information new features not found in classical information
theory. The problem of a noisy quantum channel with a classical observer
measuring the environment is introduced, and bounds on the corresponding
channel capacity proved. These bounds are always greater than for the
unobserved channel. We conclude with a summary of open problems.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 04:42:44 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Barnum",
"Howard",
""
],
[
"Nielsen",
"M. A.",
""
],
[
"Schumacher",
"Benjamin",
""
]
] |
quant-ph/9702050 | Haiqing Wei | Haiqing Wei, Xin Xue | Quantum Isomorphic Simulation | 3 pages | null | null | null | quant-ph | null | A new type of quantum simulator is proposed which can simulate any quantum
many-body system in an isomorphic manner. It can actually synthesize a
duplicate of the system to be simulated. The isomorphic simulation has the
great advantage that the inevitable coupling of the simulator to the
environment can be fully exploited in simulating thermodynamic processes.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 16:57:50 GMT"
},
{
"version": "v2",
"created": "Wed, 4 Mar 1998 07:16:47 GMT"
},
{
"version": "v3",
"created": "Thu, 5 Mar 1998 04:24:39 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Wei",
"Haiqing",
""
],
[
"Xue",
"Xin",
""
]
] |
quant-ph/9702051 | null | L. Lanz, B. Vacchini | Dynamical Semigroup Description of Coherent and Incoherent
Particle-Matter Interaction | 22 pages, latex, no figures | Int.J.Theor.Phys. 36 (1997) 67-88 | 10.1007/BF02435772 | IFUM 528/FT | quant-ph | null | The meaning of statistical experiments with single microsystems in quantum
mechanics is discussed and a general model in the framework of non-relativistic
quantum field theory is proposed, to describe both coherent and incoherent
interaction of a single microsystem with matter. Compactly developing the
calculations with superoperators, it is shown that the introduction of a time
scale, linked to irreversibility of the reduced dynamics, directly leads to a
dynamical semigroup expressed in terms of quantities typical of scattering
theory. Its generator consists of two terms, the first linked to a coherent
wavelike behaviour, the second related to an interaction having a measuring
character, possibly connected to events the microsystem produces propagating
inside matter. In case these events breed a measurement, an explicit
realization of some concepts of modern quantum mechanics ("effects" and
"operations") arises. The relevance of this description to a recent debate
questioning the validity of ordinary quantum mechanics to account for such
experimental situations as, e.g., neutron-interferometry, is briefly discussed.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 17:18:08 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Lanz",
"L.",
""
],
[
"Vacchini",
"B.",
""
]
] |
quant-ph/9702052 | Vittot | P. Duclos, P. Stovicek, M. Vittot | Perturbation of an Eigen-Value from a Dense Point Spectrum : An Example | Latex, 24 pages, 51 K | J.Phys.A30:7167-7185,1997 | 10.1088/0305-4470/30/20/018 | null | quant-ph | null | We study a perturbed Floquet Hamiltonian $K+\beta V$ depending on a coupling
constant $\beta$. The spectrum $\sigma(K)$ is assumed to be pure point and
dense. We pick up an eigen-value, namely $0\in\sigma(K)$, and show the
existence of a function $\lambda(\beta)$ defined on $I\subset\R$ such that
$\lambda(\beta) \in \sigma(K+\beta V)$ for all $\beta\in I$, 0 is a point of
density for the set $I$, and the Rayleigh-Schr\"odinger perturbation series
represents an asymptotic series for the function $\lambda(\beta)$. All ideas
are developed and demonstrated when treating an explicit example but some of
them are expected to have an essentially wider range of application.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 18:52:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Duclos",
"P.",
""
],
[
"Stovicek",
"P.",
""
],
[
"Vittot",
"M.",
""
]
] |
quant-ph/9702053 | Daniel F. V. James | Daniel F. V. James | Quantum dynamics of cold trapped ions, with application to quantum
computation | 20 pages, 7 figures, 3 tables | null | 10.1007/s003400050373 | LA-UR-97-745 | quant-ph | null | The theory of interactions between lasers and cold trapped ions as it
pertains to the design of Cirac-Zoller quantum computers is discussed. The mean
positions of the trapped ions, the eigenvalues and eigenmodes of the ions'
oscillations, the magnitude of the Rabi frequencies for both allowed and
forbidden internal transitions of the ions and the validity criterion for the
required Hamiltonian are calculated. Energy level data for a variety of ion
species is also presented.
| [
{
"version": "v1",
"created": "Thu, 27 Feb 1997 00:04:48 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"James",
"Daniel F. V.",
""
]
] |
quant-ph/9702054 | Farhad Ghaboussi | F. Ghaboussi | Uncertainty Relations for Two Dimensional Quantized Electromagnetic
Potential | Latex, 6 pages | null | null | null | quant-ph | null | The canonical quantization of flux is performed. It is shown that according
to the canonical flux quantization there must be a new uncertainty relation: $e
\Delta A_m . \Delta x_m \geq \hbar$ where $A_m$ and $\Delta x_m \geq l_B$ are
the electromagnetic gauge potential, the position uncertainty and the magnetic
length, respectively. Other arguments in favour of this uncertainty relation
are also discussed.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 16:45:53 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ghaboussi",
"F.",
""
]
] |
quant-ph/9702055 | Balachandran | A.P. Balachandran | Bringing Up a Quantum Baby | 23 pages, 2 figures ( ref. updated, no other changes ) | null | null | SU-4240-657 | quant-ph gr-qc hep-th math.QA q-alg | null | Any two infinite-dimensional (separable) Hilbert spaces are unitarily
isomorphic. The sets of all their self-adjoint operators are also therefore
unitarily equivalent. Thus if all self-adjoint operators can be observed, and
if there is no further major axiom in quantum physics than those formulated for
example in Dirac's `Quantum Mechanics', then a quantum physicist would not be
able to tell a torus from a hole in the ground. We argue that there are indeed
such axioms involving vectors in the domain of the Hamiltonian: The
``probability densities'' (hermitean forms) \psi^\dagger \chi for \psi,\chi in
this domain generate an algebra from which the classical configuration space
with its topology (and with further refinements of the axiom, its C^K and
C^infinity structures) can be reconstructed using Gel'fand - Naimark theory.
Classical topology is an attribute of only certain quantum states for these
axioms, the configuration space emergent from quantum physics getting
progressively less differentiable with increasingly higher excitations of
energy and eventually altogether ceasing to exist. After formulating these
axioms, we apply them to show the possibility of topology change and to discuss
quantized fuzzy topologies. Fundamental issues concerning the role of time in
quantum physics are also addressed.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 20:37:34 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Mar 1997 22:27:50 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Balachandran",
"A. P.",
""
]
] |
quant-ph/9702056 | Haiqing Wei | Xin Xue, Haiqing Wei | More on Static Quantum Computation | 2 pages | null | null | null | quant-ph | null | The construction of a universal static quantum computer actually provides
another proof of the NP-hardness of spin-glass problems.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 21:02:35 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Mar 1998 01:23:50 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Xue",
"Xin",
""
],
[
"Wei",
"Haiqing",
""
]
] |
quant-ph/9702057 | Philip Maymin | Philip Maymin (Harvard University) | The lambda-q calculus can efficiently simulate quantum computers | 4 pages, LaTeX2e | null | null | null | quant-ph | null | We show that the lambda-q calculus can efficiently simulate quantum Turing
machines by showing how the lambda-q calculus can efficiently simulate a class
of quantum cellular automaton that are equivalent to quantum Turing machines.
We conclude by noting that the lambda-q calculus may be strictly stronger than
quantum computers because NP-complete problems such as satisfiability are
efficiently solvable in the lambda-q calculus but there is a widespread doubt
that they are efficiently solvable by quantum computers.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 22:13:11 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Maymin",
"Philip",
"",
"Harvard University"
]
] |
quant-ph/9702058 | Raymond Laflamme | Emanuel Knill, Raymond Laflamme and Wojciech H. Zurek | Resilient Quantum Computation: Error Models and Thresholds | 19 pages in RevTex, many figures, the paper is also avalaible at
http://qso.lanl.gov/qc/ | null | 10.1098/rspa.1998.0166 | null | quant-ph | null | Recent research has demonstrated that quantum computers can solve certain
types of problems substantially faster than the known classical algorithms.
These problems include factoring integers and certain physics simulations.
Practical quantum computation requires overcoming the problems of environmental
noise and operational errors, problems which appear to be much more severe than
in classical computation due to the inherent fragility of quantum
superpositions involving many degrees of freedom. Here we show that arbitrarily
accurate quantum computations are possible provided that the error per
operation is below a threshold value. The result is obtained by combining
quantum error-correction, fault tolerant state recovery, fault tolerant
encoding of operations and concatenation. It holds under physically realistic
assumptions on the errors.
| [
{
"version": "v1",
"created": "Wed, 26 Feb 1997 21:40:50 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Knill",
"Emanuel",
""
],
[
"Laflamme",
"Raymond",
""
],
[
"Zurek",
"Wojciech H.",
""
]
] |
quant-ph/9702059 | Kalle-Antti Suominen | Stig Stenholm and Asta Paloviita (Research Institute for Theoretical
Physics, University of Helsinki, Finland) | States prepared by decay | 22 pages, Latex2.09, 6 Postscript figures embedded using psfig, see
also http://www.physics.helsinki.fi/~kasuomin/ To appear in a Special Issue
of Journal of Modern Optics (1997) | J. Mod. Opt. 44, 2533-2550 (1997) | 10.1080/09500349708231899 | HU-TFT-96-43 | quant-ph | null | We consider the time evolution of a discrete state embedded in a continuum.
Results from scattering theory can be utilized to solve the initial value
problem and discuss the system as a model of wave packet preparation. Extensive
use is made of the analytic properties of the propagators, and simple model
systems are evaluated to illustrate the argument. We verify the exponential
appearence of the continuum state and its propagation as a localized wave
packet.
| [
{
"version": "v1",
"created": "Thu, 27 Feb 1997 09:22:40 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Stenholm",
"Stig",
"",
"Research Institute for Theoretical\n Physics, University of Helsinki, Finland"
],
[
"Paloviita",
"Asta",
"",
"Research Institute for Theoretical\n Physics, University of Helsinki, Finland"
]
] |
quant-ph/9702060 | Marco Toller | M. Toller (Dipartimento di Fisica dell'Universita', Trento, Italia) | On the Quantum Space-Time Coordinates of an Event | 21 pages, LATEX, no figures. This revised version contains several
more important references and a short section on non-normalized positive
operator valued measures | null | null | null | quant-ph | null | This paper gives a representation of the most general positive operator
valued measure in Minkowski space-time, covariant with respect to the Poincare'
group. It provides the correct mathematical description of the space-time
coordinates of a quantum event, described by a quantum object with suitable
properties. It is known that these coordinates cannot be represented by
self-adjoint operators or by the corresponding projection valued measure.
| [
{
"version": "v1",
"created": "Thu, 27 Feb 1997 10:59:42 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Mar 1997 11:01:00 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Toller",
"M.",
"",
"Dipartimento di Fisica dell'Universita', Trento, Italia"
]
] |
quant-ph/9702061 | Alexander Chebotarev | Alexander M. Chebotarev | Quantum stochastic differential equation is unitary equivalent to a
symmetric boundary value problem in Fock space | 28 pages, LaTeX, 86Kb (AMS classification 81S25, 47N50, 46L60) | null | null | null | quant-ph | null | We show a new remarkable connection between the symmetric form of a quantum
stochastic differential equation (QSDE) and the strong resolvent limit of
Schr\"odinger equations in Fock space: the strong resolvent limit is unitary
equivalent to QSDE in the adapted (or Ito) form, and the weak limit is unitary
equivalent to the symmetric (or Stratonovich) form of QSDE.
We prove that QSDE is unitary equivalent to a symmetric boundary value
problem for the Schr\"odinger equation in Fock space. The boundary condition
describes standard jumps of the phase and amplitude of components of Fock
vectors belonging to the range of the resolvent. The corresponding Markov
evolution equation (the Lindblad or Markov master equation) is derived from the
boundary value problem for the Schr\"odinger equation.}
| [
{
"version": "v1",
"created": "Thu, 27 Feb 1997 16:28:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chebotarev",
"Alexander M.",
""
]
] |
quant-ph/9703001 | Lev Vaidman | Lev Vaidman | On the validity of the Aharonov-Bergmann-Lebowitz rule | 2 pages, 1 eps figure, LaTeX | null | 10.1103/PhysRevA.57.2251 | TAUP 2411-97 | quant-ph | null | It is argued that the proof of Cohen [Phys. Rev. A 51, 4373 (1995)] which
shows that an application of the Aharonov-Bergmann-Lebowitz (ABL) rule leads to
contradiction with predictions of quantum theory is erroneous. A generalization
of the ABL rule for the case of an incomplete final measurement (which is
needed for the analysis of Cohen's proof) is presented.
| [
{
"version": "v1",
"created": "Mon, 3 Mar 1997 09:49:21 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Vaidman",
"Lev",
""
]
] |
quant-ph/9703002 | Eric Rains | Eric M. Rains, R. H. Hardin, Peter W. Shor, and N. J. A. Sloane (AT&T
Research) | A nonadditive quantum code | 2 pages, RevTeX. More information is available at
http://www.research.att.com/~njas/doc/quant.html . Updated version includes
an expanded introduction, and a more detailed discussion of the structure of
the code | Phys.Rev.Lett.79:953-954,1997 | 10.1103/PhysRevLett.79.953 | null | quant-ph | null | Up to now every good quantum error-correcting code discovered has had the
structure of an eigenspace of an Abelian group generated by tensor products of
Pauli matrices; such codes are known as stabilizer or additive codes. In this
letter we present the first example of a code that is better than any code of
this type. It encodes six states in five qubits and can correct the erasure of
any single qubit.
| [
{
"version": "v1",
"created": "Tue, 4 Mar 1997 19:36:49 GMT"
},
{
"version": "v2",
"created": "Fri, 9 May 1997 15:15:14 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Rains",
"Eric M.",
"",
"AT&T\n Research"
],
[
"Hardin",
"R. H.",
"",
"AT&T\n Research"
],
[
"Shor",
"Peter W.",
"",
"AT&T\n Research"
],
[
"Sloane",
"N. J. A.",
"",
"AT&T\n Research"
]
] |
quant-ph/9703003 | null | L. Lanz, O. Melsheimer and B. Vacchini | Subdynamics through Time Scales and Scattering Maps in Quantum Field
Theory | 16 pages, latex, no figures, to appear in the Proceedings of the
Third International Conference on Quantum Communication & Measurement 1996
(Hakone, Japan) | Quantum communication, computing, and measurement, p. 339-353,
O.Hirota, A.S.Holevo and C.M.Caves eds., Plenum, New York 1997. | null | null | quant-ph | null | It is argued that the dynamics of an isolated system, due to the concrete
procedure by which it is separated from the environment, has a non-Hamiltonian
contribution. By a unified quantum field theoretical treatment of typical
subdynamics, e.g., hydrodynamics, kinetic theory, master equation for a
particle interacting with matter, we look for the structure of this more
general dynamics.
| [
{
"version": "v1",
"created": "Tue, 4 Mar 1997 10:02:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lanz",
"L.",
""
],
[
"Melsheimer",
"O.",
""
],
[
"Vacchini",
"B.",
""
]
] |
quant-ph/9703004 | Pawel Horodecki | Pawel Horodecki | Separability criterion and inseparable mixed states with positive
partial transposition | It is improved and extended version of the former manuscript, in
particular the theorem concerning finite decomposition of separable states
has been included, 14 pages, RevTeX | Phys.Lett. A232 (1997) 333 | 10.1016/S0375-9601(97)00416-7 | null | quant-ph | null | It is shown that any separable state on Hilbert space ${\cal H}={\cal
H}_1\otimes{\cal H}_2$, can be written as a convex combination of N pure
product states with $N\leq (dim{\cal H})^2$. Then a new separability criterion
for mixed states in terms of range of density matrix is obtained. It is used in
construction of inseparable mixed states with positive partial transposition in
the case of $3\times 3$ and $2\times 4$ systems. The states represent an
entanglement which is hidden in a more subtle way than it has been known so
far.
| [
{
"version": "v1",
"created": "Tue, 4 Mar 1997 17:25:38 GMT"
},
{
"version": "v2",
"created": "Fri, 23 May 1997 13:50:05 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Horodecki",
"Pawel",
""
]
] |
quant-ph/9703005 | Crispin Gardiner | C.W. Gardiner | A particle-number-conserving Bogoliubov method which demonstrates the
validity of the time-dependent Gross-Pitaevskii equation for a highly
condensed Bose gas | RevTeX, 11 pages | null | 10.1103/PhysRevA.56.1414 | VUWQO-001 | quant-ph | null | The Bogoliubov method for the excitation spectrum of a Bose-condensed gas is
generalized to apply to a gas with an exact large number $ N$ of particles.
This generalization yields a description of the Schr\"odinger picture field
operators as the product of an annihilation operator $A$ for the total number
of particles and the sum of a ``condensate wavefunction'' $\xi(x)$ and a phonon
field operator $\chi(x)$ in the form $\psi(x) \approx A\{\xi(x) +
\chi(x)/\sqrt{N}\}$ when the field operator acts on the N particle subspace. It
is then possible to expand the Hamiltonian in decreasing powers of $\sqrt{N}$,
an thus obtain solutions for eigenvalues and eigenstates as an asymptotic
expansion of the same kind. It is also possible to compute all matrix elements
of field operators between states of different N.
| [
{
"version": "v1",
"created": "Wed, 5 Mar 1997 03:37:58 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Gardiner",
"C. W.",
""
]
] |
quant-ph/9703006 | Olavo Leopoldino da Silva Filho | L.S.F. Olavo | Quantum Mechanics as a Classical Theory XV: Thermodynamical Derivation | 19 pages, latex, no figures | null | null | UnB-15 | quant-ph | null | We present in this continuation paper a new axiomatic derivation of the
Schr\"odinger equation from three basic postulates. This new derivation sheds
some light on the thermodynamic character of the quantum formalism. We also
show the formal connection between this derivation and the one previously done
by other means. Some considerations about metaestability are also drawn. We
return to an example previously developed to show how the connection between
both derivations works.
| [
{
"version": "v1",
"created": "Wed, 5 Mar 1997 14:03:07 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Olavo",
"L. S. F.",
""
]
] |
quant-ph/9703007 | Melvin Brown | M. R. Brown (Birkbeck College, London) | The quantum potential: the breakdown of classical symplectic symmetry
and the energy of localisation and dispersion | 12 pages, RevTeX, 7 PS figures. Change made to title | null | null | null | quant-ph | null | The composition of the quantum potential and its role in the breakdown of
classical symplectic symmetry in quantum mechanics is investigated. General
expressions are derived for the quantum potential in both configuration space
and momentum space representations. By comparing the configuration space and
momentum space representations of the causal interpretation of quantum
mechanics, the quantum potential is shown to break the symplectic symmetry that
exists between these two representations in classical mechanics. In addition,
it is shown that the quantum potential in configuration space may be expressed
as the sum of a momentum dispersion energy and a spatial localisation energy; a
complementary expression for the quantum potential being found in the momentum
representation. The composition and role of the quantum potential in both
representations is analysed for a particle in a linear potential and for two
eigenstates of the quantum harmonic oscillator.
| [
{
"version": "v1",
"created": "Thu, 6 Mar 1997 19:36:00 GMT"
},
{
"version": "v2",
"created": "Thu, 22 Mar 2001 21:57:57 GMT"
},
{
"version": "v3",
"created": "Tue, 5 Feb 2002 22:11:01 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Brown",
"M. R.",
"",
"Birkbeck College, London"
]
] |
quant-ph/9703008 | Athene Donald | Matthew J. Donald | On Many-Minds Interpretations of Quantum Theory | 16 pages, plain TeX, no macros required. Revised following comments
November 1997 | null | null | null | quant-ph | null | This paper is a response to some recent discussions of many-minds
interpretations in the philosophical literature. After an introduction to the
many-minds idea, the complexity of quantum states for macroscopic objects is
stressed. Then it is proposed that a characterization of the physical structure
of observers is a proper goal for physical theory. It is argued that an
observer cannot be defined merely by the instantaneous structure of a brain,
but that the history of the brain's functioning must also be taken into
account. Next the nature of probability in many-minds interpretations is
discussed and it is suggested that only discrete probability models are needed.
The paper concludes with brief comments on issues of actuality and identity
over time.
| [
{
"version": "v1",
"created": "Thu, 6 Mar 1997 11:49:00 GMT"
},
{
"version": "v2",
"created": "Sun, 30 Nov 1997 15:47:59 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Donald",
"Matthew J.",
""
]
] |
quant-ph/9703009 | null | Ming Li (University of Waterloo), John Tromp (CWI), Paul Vitanyi (CWI
and University of Amsterdam) | Reversible Simulation of Irreversible Computation by Pebble Games | 11 pages, Latex, Submitted to Physica D | Physica D120 (1998) 168-176 | 10.1016/S0167-2789(98)00052-9 | CWI Tech Report 1996 | quant-ph cs.CC cs.DS | null | Reversible simulation of irreversible algorithms is analyzed in the stylized
form of a `reversible' pebble game. While such simulations incur little
overhead in additional computation time, they use a large amount of additional
memory space during the computation. The reacheable reversible simulation
instantaneous descriptions (pebble configurations) are characterized
completely. As a corollary we obtain the reversible simulation by Bennett and
that among all simulations that can be modelled by the pebble game, Bennett's
simulation is optimal in that it uses the least auxiliary space for the
greatest number of simulated steps. One can reduce the auxiliary storage
overhead incurred by the reversible simulation at the cost of allowing limited
erasing leading to an irreversibility-space tradeoff. We show that in this
resource-bounded setting the limited erasing needs to be performed at precise
instants during the simulation. We show that the reversible simulation can be
modified so that it is applicable also when the simulated computation time is
unknown.
| [
{
"version": "v1",
"created": "Thu, 6 Mar 1997 17:32:23 GMT"
},
{
"version": "v2",
"created": "Thu, 10 Apr 1997 17:56:23 GMT"
},
{
"version": "v3",
"created": "Fri, 11 Apr 1997 15:02:42 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Li",
"Ming",
"",
"University of Waterloo"
],
[
"Tromp",
"John",
"",
"CWI"
],
[
"Vitanyi",
"Paul",
"",
"CWI\n and University of Amsterdam"
]
] |
quant-ph/9703010 | Alexander Y. Vlasov | Alexander Yu. Vlasov (FCR/IRH, St.-Petersburg, Russia) | Quantum Computations and Images Recognition | 7 pages, LaTeX2.09; Talk given at QCM'96 (September 1996, Japan) | null | null | QCY-VAY09-230996 | quant-ph | null | The using of quantum parallelism is often connected with consideration of
quantum system with huge dimension of space of states. The n-qubit register can
be described by complex vector with 2^n components (it belongs to n'th tensor
power of qubit spaces). For example, for algorithm of factorization of numbers
by quantum computer n can be about a few hundreds for some realistic
applications for cryptography. The applications described further are used some
other properties of quantum systems and they do not demand such huge number of
states.
The term "images recognition" is used here for some broad class of problems.
For example, we have a set of some objects V_i and function of "likelihood":
F(V,W) < F(V,V) = 1
If we have some "noisy" or "distorted" image W, we can say that recognition
of W is V_i, if F(W,V_i) is near 1 for some V_i.
| [
{
"version": "v1",
"created": "Fri, 7 Mar 1997 01:58:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Vlasov",
"Alexander Yu.",
"",
"FCR/IRH, St.-Petersburg, Russia"
]
] |
quant-ph/9703011 | Kalle-Antti Suominen | Asta Paloviita (Helsinki Institute of Physics, Finland; Present
address: Nokia Research Centre, Tampere, Finland), Kalle-Antti Suominen
(Theoretical Physics Division, Department of Physics, University of Helsinki,
Finland) Stig Stenholm (Helsinki Institute of Physics, Finland) | Weisskopf-Wigner model for wave packet excitation | 14 pages, Latex2.09, 9 Postscript figures embedded using psfig, see
also http://www.physics.helsinki.fi/~kasuomin/ | J.Phys. B30 (1997) 2623 | 10.1088/0953-4075/30/11/014 | HIP-1997-09 | quant-ph | null | We consider a laser induced molecular excitation process as a decay of a
single energy state into a continuum. The analytic results based on
Weisskopf-Wigner approach and perturbation calculations are compared with
numerical wave packet results. We find that the decay model describes the
excitation process well within the expected parameter region.
| [
{
"version": "v1",
"created": "Fri, 7 Mar 1997 10:11:47 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Paloviita",
"Asta",
"",
"Helsinki Institute of Physics, Finland; Present\n address: Nokia Research Centre, Tampere, Finland"
],
[
"Suominen",
"Kalle-Antti",
"",
"Theoretical Physics Division, Department of Physics, University of Helsinki,\n Finland"
],
[
"Stenholm",
"Stig",
"",
"Helsinki Institute of Physics, Finland"
]
] |
quant-ph/9703012 | Paul Slater | Paul B. Slater (University of California, Santa Barbara) | Comparative Noninformativities of Quantum Priors Based on Monotone
Metrics | 7 pages, LaTeX, minor changes, to appear in Physics Letters A | Phys.Lett. A247 (1998) 1-8 | 10.1016/S0375-9601(98)00556-8 | null | quant-ph physics.data-an | null | We consider a family of prior probability distributions of particular
interest, all being defined on the three-dimensional convex set of two-level
quantum systems. Each distribution is, following recent work of Petz and Sudar,
taken to be proportional to the volume element of a monotone metric on that
Riemannian manifold. We apply an entropy-based test (a variant of one recently
developed by Clarke) to determine which of two priors is more noninformative in
nature. This involves converting them to posterior probability distributions
based on some set of hypothesized outcomes of measurements of the quantum
system in question. It is, then, ascertained whether or not the original
relative entropy (Kullback-Leibler distance) between a pair of priors increases
or decreases when one of them is exchanged with its corresponding posterior.
The findings lead us to assert that the maximal monotone metric yields the most
noninformative (prior) distribution and the minimal monotone (that is, the
Bures) metric, the least. Our conclusions both agree and disagree, in certain
respects, with ones recently reached by Hall, who relied upon a less specific
test criterion than our entropy-based one.
| [
{
"version": "v1",
"created": "Fri, 7 Mar 1997 21:47:19 GMT"
},
{
"version": "v10",
"created": "Tue, 4 Aug 1998 18:11:03 GMT"
},
{
"version": "v2",
"created": "Mon, 17 Mar 1997 17:37:48 GMT"
},
{
"version": "v3",
"created": "Thu, 3 Apr 1997 19:56:06 GMT"
},
{
"version": "v4",
"created": "Fri, 9 May 1997 20:42:32 GMT"
},
{
"version": "v5",
"created": "Thu, 15 May 1997 21:24:58 GMT"
},
{
"version": "v6",
"created": "Fri, 16 May 1997 15:35:50 GMT"
},
{
"version": "v7",
"created": "Fri, 6 Mar 1998 17:41:47 GMT"
},
{
"version": "v8",
"created": "Wed, 1 Apr 1998 17:08:09 GMT"
},
{
"version": "v9",
"created": "Wed, 29 Jul 1998 16:13:51 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Slater",
"Paul B.",
"",
"University of California, Santa Barbara"
]
] |
quant-ph/9703013 | Alexander S. Holevo | M.V.Burnashev, A.S.Holevo | On Reliability Function of Quantum Communication Channel | 12 pages, Latex209, correct proof of Proposition 1 is given, 2
figures added | null | null | null | quant-ph | null | The reliability function gives the rate of exponential convergence to zero of
the error probability in a communication channel. In this paper bounds for the
reliability function of a quantum pure state channel are given, reminiscent of
the corresponding classical bounds. This in particular suggests an alternative
proof of the coding theorem for quantum noiseless channel, which would make no
use of the notion of typical subspace. Example of binary quantum channel is
considered in some detail.
| [
{
"version": "v1",
"created": "Sat, 8 Mar 1997 17:18:43 GMT"
},
{
"version": "v2",
"created": "Thu, 15 May 1997 20:10:23 GMT"
},
{
"version": "v3",
"created": "Mon, 20 Jul 1998 13:16:22 GMT"
},
{
"version": "v4",
"created": "Wed, 12 Aug 1998 14:30:46 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Burnashev",
"M. V.",
""
],
[
"Holevo",
"A. S.",
""
]
] |
quant-ph/9703014 | Dr. Eric L. Bolda | Eric L. Bolda, Sze M. Tan and Dan F. Walls | Reconstruction of the joint state of a two-mode Bose-Einstein condensate | 4 pages (REVTeX), 5 figures (PostScript) | null | 10.1103/PhysRevLett.79.4719 | null | quant-ph | null | We propose a scheme to reconstruct the state of a two-mode Bose-Einstein
condensate, with a given total number of atoms, using an atom interferometer
that requires beam splitter, phase shift and non-ideal atom counting
operations. The density matrix in the number-state basis can be computed
directly from the probabilities of different counts for various phase shifts
between the original modes, unless the beamsplitter is exactly balanced.
Simulated noisy data from a two-mode coherent state is produced and the state
is reconstructed, for 49 atoms. The error can be estimated from the singular
values of the transformation matrix between state and probability data.
| [
{
"version": "v1",
"created": "Mon, 10 Mar 1997 02:36:16 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Bolda",
"Eric L.",
""
],
[
"Tan",
"Sze M.",
""
],
[
"Walls",
"Dan F.",
""
]
] |
quant-ph/9703015 | G. Kunstatter | Mark Burgess (Oslo), Margaret Carrington and Gabor Kunstatter
(Winnipeg) | The Effective Action for a Relativistic Jaynes-Cummings Model | 29 pages, Latex (RevTex) | null | 10.1139/cjp-76-7-539 | null | quant-ph hep-th | null | We describe an effective field theory for atomic lasers which reduces to the
Jaynes-Cummings model in the non-relativistic, single mode limit. Our action
describes a multi-mode system, with general polarizations and Lorentz
invariance and can therefore be used in all contexts from the astrophysical to
the laboratory. We show how to compute the effective action for this model and
perform the calculation explicitly at the one loop level. Our model provides a
way of analyzing a many-particle, two-state model with arbitrary boundary
conditions.
| [
{
"version": "v1",
"created": "Mon, 10 Mar 1997 21:55:42 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Burgess",
"Mark",
"",
"Oslo"
],
[
"Carrington",
"Margaret",
"",
"Winnipeg"
],
[
"Kunstatter",
"Gabor",
"",
"Winnipeg"
]
] |
quant-ph/9703016 | Markus Grassl | Markus Grassl and Thomas Beth (Universitaet Karlsruhe) | A Note on Non-Additive Quantum Codes | 4 pages, RevTeX, no figures, preliminary report | null | null | null | quant-ph | null | A method to combine two quantum error-correcting codes is presented. Even
when starting with additive codes, the resulting code might be non-additive.
Furthermore, the notion of the erasure space is introduced which gives a full
characterisation of the erasure-correcting capabilities of the codes. For the
special case that the two codes are unitary images of each other, the erasure
space and the pure erasure space of the resulting code can be calculated.
| [
{
"version": "v1",
"created": "Mon, 10 Mar 1997 20:08:39 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Grassl",
"Markus",
"",
"Universitaet Karlsruhe"
],
[
"Beth",
"Thomas",
"",
"Universitaet Karlsruhe"
]
] |
quant-ph/9703017 | Peter Nattermann | Peter Nattermann | Generalized Quantum Mechanics and Nonlinear Gauge Transformations | 13 pages, RevTeX, uses amsfonts and bbm; available as a preprint on
http://www.pt.tu-clausthal.de/preprints/asi-tpa/004-97.ps.gz | null | null | null | quant-ph hep-th physics.gen-ph | null | Motivated by the problems of interpretation of a nonlinear evolution equation
in quantum mechanics we discuss in this contribution the concept of nonlinear
gauge transformations, that has recently been introduced in joint work with
Doebner and Goldin, in the framework of Mielnik's Generalized Quantum
Mechanics. Using these gauge transformations we construct linear quantum
systems in a ``nonlinear disguise'', and a gauge generalization of these (in
analogy to the minimal coupling of orthodox quantum mechanics) leads to a
unification of Bialynicki-Birula--Mycielski and Doebner--Goldin evolution
equations for the quantum system. The notion of nonlinear observables
introduced by L\"ucke is finally discussed in the same framework.
| [
{
"version": "v1",
"created": "Wed, 12 Mar 1997 12:13:01 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Nattermann",
"Peter",
""
]
] |
quant-ph/9703018 | Lev Vaidman | Lev Vaidman | The analysis of Hardy's experiment revisited | 3 pages, LaTeX | null | null | TAUP 2413-97 | quant-ph | null | Cohen and Hiley [Phys. Rev. A 52, 76 (1995)] have criticized the analysis of
Hardy's gedanken experiment according to which the contradiction with quantum
theory in Hardy's experiment arises due the failure of the "product rule" for
the elements of reality of pre- and post-selected systems. It is argued that
the criticism of Cohen and Hiley is not sound.
| [
{
"version": "v1",
"created": "Wed, 12 Mar 1997 14:09:28 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Vaidman",
"Lev",
""
]
] |
quant-ph/9703019 | Xinwei Kong | Xinwei Kong, Finn Ravndal | Radiative Corrections to the Casimir Energy | 7 pages, Latex | Phys.Rev.Lett. 79 (1997) 545-548 | 10.1103/PhysRevLett.79.545 | null | quant-ph hep-ph | null | The lowest radiative correction to the Casimir energy density between two
parallel plates is calculated using effective field theory. Since the
correlators of the electromagnetic field diverge near the plates, the
regularized energy density is also divergent. However, the regularized integral
of the energy density is finite and varies with the plate separation L as
1/L^7. This apparently paradoxical situation is analyzed in an equivalent, but
more transparent theory of a massless scalar field in 1+1 dimensions confined
to a line element of length L and satisfying Dirichlet boundary conditions.
| [
{
"version": "v1",
"created": "Wed, 12 Mar 1997 17:52:33 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Kong",
"Xinwei",
""
],
[
"Ravndal",
"Finn",
""
]
] |
quant-ph/9703020 | null | V.I. Man'ko, G.Marmo, F.Zaccaria | Deformations and Nonlinear Systems | 23 pages,LATEX, to be published in Rend.Sem.Mat.Univ.Polit.Torino,
volume 54 (1996), as Proceedings of Workshop on "Geometry and Plysics" Vietri
Sept.29 1996, (S.Benenti, G.Marmo, A.Simoni, Eds.) | Rend.Sem.Mat.Univ.Politec.Torino 54 (1996) 337-352 | null | null | quant-ph | null | The q-deformation of harmonic oscillators is shown to lead to q-nonlinear
vibrations. The examples of q-nonlinearized wave equation and Schr\"odinger
equation are considered. The procedure is generalized to broader class of
nonlinearities related to other types of deformations. The nonlinear
noncanonical transforms used in the deformation procedure are shown to preserve
in some cases the linear dynamical equations, for instance, for the harmonic
oscillators. The nonlinear coherent states and some physical aspects of the
deformations are reviewed.
| [
{
"version": "v1",
"created": "Wed, 12 Mar 1997 16:30:15 GMT"
}
] | 2019-08-17T00:00:00 | [
[
"Man'ko",
"V. I.",
""
],
[
"Marmo",
"G.",
""
],
[
"Zaccaria",
"F.",
""
]
] |
quant-ph/9703021 | Gyula Bene | Gyula Bene (Eotvos University, Budapest) | Quantum reference systems: a new framework for quantum mechanics | 49 pages, LaTeX, to appear in Physica A | null | 10.1016/S0378-4371(97)00254-9 | null | quant-ph | null | A new interpretation of nonrelativistic quantum mechanics is presented. It
explains the violation of Bell's inequality by maintaining realism and the
principle of locality. Schrodinger's cat paradox and the
Einstein-Podolsky-Rosen paradox are solved, too. The new approach assumes the
universal validity of the Schrodinger equation, while von Neumann's postulates
about the measurement process are replaced with a new, consistent set of
postulates. The underlying idea is that quantum states depend on quantum
reference systems in a fundamental way. Quantum reference systems (a new
concept, first introduced in this paper) are themselves physical systems which
contain the system to be described.
| [
{
"version": "v1",
"created": "Thu, 13 Mar 1997 17:08:19 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Bene",
"Gyula",
"",
"Eotvos University, Budapest"
]
] |
quant-ph/9703022 | null | Ming Li (University of Waterloo), Paul Vitanyi (CWI and University of
Amsterdam) | Reversibility and Adiabatic Computation: Trading Time and Space for
Energy | 30 pages, Latex. Lemma 2.3 should be replaced by the slightly better
``There is a winning strategy with $n+2$ pebbles and $m-1$ erasures for
pebble games $G$ with $T_G= m2^n$, for all $m \geq 1$'' with appropriate
further changes (as pointed out by Wim van Dam). This and further work on
reversible simulations as in Section 2 appears in quant-ph/9703009 | Proc. Royal Society of London, Series A, 452(1996), 769-789 | 10.1098/rspa.1996.0039 | null | quant-ph cs.CC cs.CE cs.DS | null | Future miniaturization and mobilization of computing devices requires energy
parsimonious `adiabatic' computation. This is contingent on logical
reversibility of computation. An example is the idea of quantum computations
which are reversible except for the irreversible observation steps. We propose
to study quantitatively the exchange of computational resources like time and
space for irreversibility in computations. Reversible simulations of
irreversible computations are memory intensive. Such (polynomial time)
simulations are analysed here in terms of `reversible' pebble games. We show
that Bennett's pebbling strategy uses least additional space for the greatest
number of simulated steps. We derive a trade-off for storage space versus
irreversible erasure. Next we consider reversible computation itself. An
alternative proof is provided for the precise expression of the ultimate
irreversibility cost of an otherwise reversible computation without
restrictions on time and space use. A time-irreversibility trade-off hierarchy
in the exponential time region is exhibited. Finally, extreme
time-irreversibility trade-offs for reversible computations in the thoroughly
unrealistic range of computable versus noncomputable time-bounds are given.
| [
{
"version": "v1",
"created": "Thu, 13 Mar 1997 18:24:42 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Li",
"Ming",
"",
"University of Waterloo"
],
[
"Vitanyi",
"Paul",
"",
"CWI and University of\n Amsterdam"
]
] |
quant-ph/9703023 | null | W. Tittel, J. Brendel, T. Herzog, H. Zbinden, and N. Gisin | Non-local two-photon correlations using interferometers physically
separated by 35 meters | 9 pages including 3 postscript figures, to be published in Europhys.
Lett | null | 10.1209/epl/i1997-00509-0 | null | quant-ph | null | An experimental demonstration of quantum correlations is presented. Energy
and time entangled photons at wavelengths of 704 and 1310 nm are produced by
parametric downconversion in KNbO3 and are sent through optical fibers into a
bulk-optical (704 nm) and an all-fiber Michelson-interferometer (1310 nm),
respectively. The two interferometers are located 35 meters aside from one
another. Using Faraday-mirrors in the fiber-interferometer, all birefringence
effects in the fibers are automatically compensated. We obtained two-photon
fringe visibilities of up to 95 % from which one can project a violation of
Bell's inequality by 8 standard deviations. The good performance and the
auto-aligning feature of Faraday-mirror interferometers show their potential
for a future test of Bell's inequalities in order to examine
quantum-correlations over long distances.
| [
{
"version": "v1",
"created": "Fri, 14 Mar 1997 15:00:47 GMT"
},
{
"version": "v2",
"created": "Wed, 17 Dec 1997 10:45:46 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Tittel",
"W.",
""
],
[
"Brendel",
"J.",
""
],
[
"Herzog",
"T.",
""
],
[
"Zbinden",
"H.",
""
],
[
"Gisin",
"N.",
""
]
] |
quant-ph/9703024 | Bruno Huttner | H.Zbinden, J.D.Gautier, N.Gisin, B.Huttner, A.Muller, and W.Tittel | Interferometry with Faraday mirrors for quantum cryptography | 8 Pages, including one Postscript Figure, Latex (Revtex style). To be
published in Elect. Lett. 7 (27/03/97) | null | null | null | quant-ph | null | Quantum Cryptography over 23km of installed Telecom fiber using a novel
interferometer with Faraday mirrors is presented. The interferometer needs no
alignment nor polarization control and features 99.8% fringe visibility. A
secret key of 20kbit length with a error rate of 1.35% for 0.1 photon per pulse
was produced.
| [
{
"version": "v1",
"created": "Fri, 14 Mar 1997 16:14:29 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Zbinden",
"H.",
""
],
[
"Gautier",
"J. D.",
""
],
[
"Gisin",
"N.",
""
],
[
"Huttner",
"B.",
""
],
[
"Muller",
"A.",
""
],
[
"Tittel",
"W.",
""
]
] |
quant-ph/9703025 | Martin Plenio | V. Vedral, M.B. Plenio, K. Jacobs and P. L. Knight (Imperial College
London) | Statistical Inference, Distinguishability of Quantum States, And Quantum
Entanglement | 11 pages no figures, to appear in Phys. Rev. A | Phys.Rev. A56 (1997) 4452 | 10.1103/PhysRevA.56.4452 | null | quant-ph | null | We argue from the point of view of statistical inference that the quantum
relative entropy is a good measure for distinguishing between two quantum
states (or two classes of quantum states) described by density matrices. We
extend this notion to describe the amount of entanglement between two quantum
systems from a statistical point of view. Our measure is independent of the
number of entangled systems and their dimensionality.
| [
{
"version": "v1",
"created": "Sat, 15 Mar 1997 14:42:12 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Aug 1997 12:16:41 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Vedral",
"V.",
"",
"Imperial College\n London"
],
[
"Plenio",
"M. B.",
"",
"Imperial College\n London"
],
[
"Jacobs",
"K.",
"",
"Imperial College\n London"
],
[
"Knight",
"P. L.",
"",
"Imperial College\n London"
]
] |
quant-ph/9703026 | T. Opatrny | T. Opatrny (Jena, Olomouc), D.-G. Welsch (Jena), and W. Vogel
(Rostock) | Least-squares inversion for density-matrix reconstruction | 16 pages, REVTeX, 6 PS figures included | null | 10.1103/PhysRevA.56.1788 | null | quant-ph | null | We propose a method for reconstruction of the density matrix from measurable
time-dependent (probability) distributions of physical quantities. The
applicability of the method based on least-squares inversion is - compared with
other methods - very universal. It can be used to reconstruct quantum states of
various systems, such as harmonic and and anharmonic oscillators including
molecular vibrations in vibronic transitions and damped motion. It also enables
one to take into account various specific features of experiments, such as
limited sets of data and data smearing owing to limited resolution. To
illustrate the method, we consider a Morse oscillator and give a comparison
with other state-reconstruction methods suggested recently.
| [
{
"version": "v1",
"created": "Sun, 16 Mar 1997 14:02:17 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Opatrny",
"T.",
"",
"Jena, Olomouc"
],
[
"Welsch",
"D. -G.",
"",
"Jena"
],
[
"Vogel",
"W.",
"",
"Rostock"
]
] |
quant-ph/9703027 | David Meyer | David A. Meyer | Quantum lattice gases and their invariants | 19 pages, plain TeX, 11 PostScript figures included with epsf.tex
(ignore the under/overfull \vbox error messages) | null | 10.1142/S0129183197000618 | null | quant-ph comp-gas cond-mat.stat-mech nlin.CG | null | The one particle sector of the simplest one dimensional quantum lattice gas
automaton has been observed to simulate both the (relativistic) Dirac and
(nonrelativistic) Schroedinger equations, in different continuum limits. By
analyzing the discrete analogues of plane waves in this sector we find
conserved quantities corresponding to energy and momentum. We show that the
Klein paradox obtains so that in some regimes the model must be considered to
be relativistic and the negative energy modes interpreted as positive energy
modes of antiparticles. With a formally similar approach--the Bethe ansatz--we
find the evolution eigenfunctions in the two particle sector of the quantum
lattice gas automaton and conclude by discussing consequences of these
calculations and their extension to more particles, additional velocities, and
higher dimensions.
| [
{
"version": "v1",
"created": "Sun, 16 Mar 1997 23:22:50 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Meyer",
"David A.",
""
]
] |
quant-ph/9703028 | Holger Lyre | Holger Lyre | Quantum Space-Time and Tetrads | 6 pages, submitted to International Journal of Theoretical Physics | null | null | null | quant-ph | null | The description of space-time in a quantum theoretical framework must be
considered as a fundamental problem in physics. Most attempts start with an
already given classical space-time - then the quantization is done. In contrast
to this the central assumption in this paper is not to start with space-time,
but to derive it from some more abstract presuppositions like this is done in
von Weizsaecker's "quantum theory of ur-alternatives". Mathematically the
transition from a manifold with spin structure to a manifold with four real
space-time coordinates has to be considered. The suggestion is made that this
transition can be well described by using a tetradial formalism which appears
to be the most natural connection between ur-spinors and real four-vectors.
| [
{
"version": "v1",
"created": "Mon, 17 Mar 1997 23:33:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lyre",
"Holger",
""
]
] |
quant-ph/9703029 | Mike Ashworth | M. C. Ashworth | Coherent State Approach to Quantum Clocks | 13 pages, Latex | Phys.Rev. D58 (1998) 104008 | 10.1103/PhysRevD.58.104008 | null | quant-ph gr-qc | null | The ``problem of time'' has been a pressing issue in quantum gravity for some
time. To help understand this problem, Rovelli proposed a model of a two
harmonic oscillators system where one of the oscillators can be thought of as a
``clock'' for the other oscillator thus giving a natural time reference frame
for the system. Recently, the author has constructed an explicit form for the
coherent states on the reduced phase space of this system in terms of Klauder's
projection operator approach. In this paper, by using coherent state
representations and other tools from coherent state quantization, I investigate
the construction of gauge invariant operators on this reduced phase space, and
the ability to use a quantum oscillator as a ``clock.''
| [
{
"version": "v1",
"created": "Mon, 17 Mar 1997 23:35:10 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Ashworth",
"M. C.",
""
]
] |
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