id
stringlengths 9
16
| submitter
stringlengths 1
64
⌀ | authors
stringlengths 3
62.8k
| title
stringlengths 1
382
| comments
stringlengths 1
1.15k
⌀ | journal-ref
stringlengths 1
557
⌀ | doi
stringlengths 7
153
⌀ | report-no
stringlengths 1
509
⌀ | categories
stringlengths 5
125
| license
stringclasses 9
values | abstract
stringlengths 6
6.09k
| versions
listlengths 1
187
| update_date
timestamp[s]date 2007-05-23 00:00:00
2025-04-04 00:00:00
| authors_parsed
sequencelengths 1
2.83k
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9703030 | Jose Acacio de Barros | J. Acacio de Barros (UFJF-Brazil), Gary Oas (Stanford Univ.), and P.
Suppes (Stanford Univ.) | Comment on ``Nonlocality of a Single Photon Revisited'' | This paper has been withdrawn. A crucial mistake was found in one of
the equations | null | null | null | quant-ph | null | This paper has been withdrawn. A significantly revised version will be posted
in the near future.
| [
{
"version": "v1",
"created": "Tue, 18 Mar 1997 01:11:50 GMT"
},
{
"version": "v2",
"created": "Sun, 23 Mar 1997 19:53:34 GMT"
},
{
"version": "v3",
"created": "Fri, 3 Aug 2012 22:58:47 GMT"
}
] | 2012-08-07T00:00:00 | [
[
"de Barros",
"J. Acacio",
"",
"UFJF-Brazil"
],
[
"Oas",
"Gary",
"",
"Stanford Univ."
],
[
"Suppes",
"P.",
"",
"Stanford Univ."
]
] |
quant-ph/9703031 | Simone Warzel | B. Bodmann, H. Leschke, S. Warzel | Wiener Integration for Quantum Systems: A Unified Approach to the
Feynman-Kac formula | 12 pages, LATEX | Path integrals: Dubna '96, eds. V. S. Yarunin and M. A. Smondyrev,
Dubna 1996, JINR E96-321, ISBN: 5-85165-451-1, pp. 95-106 (with minor
improvements) | null | null | quant-ph | null | A generalized Feynman-Kac formula based on the Wiener measure is presented.
Within the setting of a quantum particle in an electromagnetic field it yields
the standard Feynman-Kac formula for the corresponding Schr\"odinger semigroup.
In this case rigorous criteria for its validity are compiled. Finally,
phase-space path-integral representations for more general quantum Hamiltonians
are derived. These representations rely on a generalized Lie-Trotter formula
which takes care of the operator-ordering multiplicity, but in general is not
related to a path measure.
| [
{
"version": "v1",
"created": "Tue, 18 Mar 1997 16:27:14 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bodmann",
"B.",
""
],
[
"Leschke",
"H.",
""
],
[
"Warzel",
"S.",
""
]
] |
quant-ph/9703032 | Michael Nielsen | M. A. Nielsen and Isaac L. Chuang | Programmable quantum gate arrays | 3 pages, REVTEX. Submitted to Phys. Rev. Lett | null | 10.1103/PhysRevLett.79.321 | null | quant-ph | null | We show how to construct quantum gate arrays that can be programmed to
perform different unitary operations on a data register, depending on the input
to some program register. It is shown that a universal quantum gate array - a
gate array which can be programmed to perform any unitary operation - exists
only if one allows the gate array to operate in a probabilistic fashion. The
universal quantum gate array we construct requires an exponentially smaller
number of gates than a classical universal gate array.
| [
{
"version": "v1",
"created": "Tue, 18 Mar 1997 17:52:54 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Nielsen",
"M. A.",
""
],
[
"Chuang",
"Isaac L.",
""
]
] |
quant-ph/9703033 | Mike Steel | M. J. Steel and D. F. Walls | Pumping of twin-trap Bose-Einstein condensates | 19 pages, 10 Postscript figures | null | null | null | quant-ph | null | We consider extensions of the twin-trap Bose-Einstein condensate system of
Javaneinen and Yoo [Phys. Rev. Lett., 76, 161--164 (1996)] to include pumping
and output couplers. Such a system permits a continual outflow of two beams of
atoms with a relative phase coherence maintained by the detection process. We
study this system for two forms of thermal pumping, both with and without the
influence of inter-atomic collisions. We also examine the effects of pumping on
the phenomenon of collapses and revivals of the relative phase between the
condensates.
| [
{
"version": "v1",
"created": "Wed, 19 Mar 1997 05:45:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Steel",
"M. J.",
""
],
[
"Walls",
"D. F.",
""
]
] |
quant-ph/9703034 | Holger Hofmann | Holger F. Hofmann, Ortwin Hess | Quantum Noise and Polarization Fluctuations in Vertical Cavity Surface
Emitting Lasers | 16 pages and 3 Figures, RevTex, to be published in Phys. Rev. A | Phys.Rev. A56 (1997) 868 | 10.1103/PhysRevA.56.868 | null | quant-ph adap-org cond-mat nlin.AO physics.optics | null | We investigate the polarization fluctuations caused by quantum noise in
quantum well vertical cavity surface emitting lasers (VCSELs). Langevin
equations are derived on the basis of a generalized rate equation model in
which the influence of competing gain-loss and frequency anisotropies is
included. This reveals how the anisotropies and the quantum well confinement
effects shape the correlations and the magnitude of fluctuations in ellipticity
and in polarization direction. According to our results all parameters used in
the rate equations may be obtained experimentally from precise time resolved
measurements of the intensity and polarization fluctuations in the emitted
laser light. To clarify the effects of anisotropies and of quantum well
confinement on the laser process in VCSELs we therefore propose time resolved
measurements of the polarization fluctuations in the laser light. In
particular, such measurements allow to distinguish the effects of frequency
anisotropy and of gain-loss anisotropy and would provide data on the spin
relaxation rate in the quantum well structure during cw operation as well as
representing a new way of experimentally determinig the linewidth enhancement
factor alpha.
| [
{
"version": "v1",
"created": "Wed, 19 Mar 1997 11:17:24 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Hofmann",
"Holger F.",
""
],
[
"Hess",
"Ortwin",
""
]
] |
quant-ph/9703035 | Artur Ekert | Artur Ekert | From quantum-codemaking to quantum code-breaking | 21 pages, LaTeX2e, psfig, multi3.cls, 1 eps figure | null | null | null | quant-ph | null | This is a semi-popular overview of quantum entanglement as an important
physical resource in the field of data security and quantum computing. After a
brief outline of entanglement's key role in philosophical debates about the
meaning of quantum mechanics I describe its current impact on both cryptography
and cryptanalysis. The paper is based on the lecture given at the conference
"Geometric Issues in the Foundations of Science" (Oxford, June 1996) in honor
of Roger Penrose.
| [
{
"version": "v1",
"created": "Wed, 19 Mar 1997 21:12:03 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ekert",
"Artur",
""
]
] |
quant-ph/9703036 | Guo Guangcan | Lu-Ming Duan and Guang-Can Guo (University of Science and Technology
of China) | Decoherence of quantum registers | 12 pages, no figures, Latex | null | null | null | quant-ph | null | We consider decoherence of quantum registers, which consist of the qubits
sited approximately periodically in space. The sites of the qubits are
permitted to have a small random variance. We derive the explicit conditions
under which the qubits can be assumed decohering independently. In other
circumstances, the qubits are decohered cooperatively. We describe two kinds of
collective decoherence. In each case, a scheme is proposed for reducing the
collective decoherence. The schemes operate by encoding the input states of the
qubits into some ''subdecoherent'' states.
| [
{
"version": "v1",
"created": "Thu, 20 Mar 1997 02:07:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Duan",
"Lu-Ming",
"",
"University of Science and Technology\n of China"
],
[
"Guo",
"Guang-Can",
"",
"University of Science and Technology\n of China"
]
] |
quant-ph/9703037 | Quesne Christiane | B. Bagchi and C. Quesne | Zero-energy states for a class of quasi-exactly solvable rational
potentials | LaTeX, 13 pages, 2 figures on request, to appear in Phys. Lett. A | Phys.Lett. A230 (1997) 1-6 | 10.1016/S0375-9601(97)00213-2 | null | quant-ph | null | Quasi-exactly solvable rational potentials with known zero-energy solutions
of the Schro\" odinger equation are constructed by starting from exactly
solvable potentials for which the Schr\" odinger equation admits an so(2,1)
potential algebra. For some of them, the zero-energy wave function is shown to
be normalizable and to describe a bound state.
| [
{
"version": "v1",
"created": "Thu, 20 Mar 1997 07:20:04 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Bagchi",
"B.",
""
],
[
"Quesne",
"C.",
""
]
] |
quant-ph/9703038 | Tien Kieu | Michael Danos (University of Chicago) and Tien D Kieu (University of
Melbourne) | Measurement in Quantum Physics | 34 pages, in Latex, revised and expanded version with an extra
appendix on decoherence | Int.J.Mod.Phys. E8 (1999) 257-287 | 10.1142/S0218301399000197 | UM-P-96/87, CU-TP-789 | quant-ph | null | The conceptual problems in quantum mechanics -- related to the collapse of
the wave function, the particle-wave duality, the meaning of measurement --
arise from the need to ascribe particle character to the wave function. As will
be shown, all these problems dissolve when working instead with quantum fields,
which have both wave and particle character. Otherwise the predictions of
quantum physics, including Bell's inequalities, coincide with those of the
standard treatments. The transfer of the results of the quantum measurement to
the classical realm is also discussed.
| [
{
"version": "v1",
"created": "Thu, 20 Mar 1997 07:23:50 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Sep 1997 08:15:21 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Danos",
"Michael",
"",
"University of Chicago"
],
[
"Kieu",
"Tien D",
"",
"University of\n Melbourne"
]
] |
quant-ph/9703039 | M. Dakna | M. Dakna, L. Knoll, and D.-G. Welsch | Photon-added state preparation via conditional measurement on a beam
splitter | 9 figures(divided in subfigures) using a4.sty | null | 10.1016/S0030-4018(97)00463-X | null | quant-ph | null | We show that conditional output measurement on a beam splitter may be used to
produce photon-added states for a large class of signal-mode quantum states,
such as thermal states, coherent states, squeezed states, displaced
photon-number states, and coherent phase states. Combining a mode prepared in
such a state and a mode prepared in a photon-number state, the state of the
mode in one of the output channels of the beam splitter ``collapses'' to a
photon-added state, provided that no photons are detected in the other output
channel. We present analytical and numerical results, with special emphasis on
photon-added coherent and squeezed vacuum states. In particular, we show that
adding photons to a squeezed vacuum yields superpositions of quantum states
which show all the typical features of Schr\"{o}dinger-cat-like states.
| [
{
"version": "v1",
"created": "Fri, 21 Mar 1997 11:01:46 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Dakna",
"M.",
""
],
[
"Knoll",
"L.",
""
],
[
"Welsch",
"D. -G.",
""
]
] |
quant-ph/9703040 | Guo Guangcan | Lu-Ming Duan and Guang-Can Guo (University of Science and Technology
of China) | Preserving coherence in quantum computation by pairing quantum bits | 12 pages, Latex, some correction in the reference and introduction.
Jour-ref: Phys. Rev. Lett. 79, 1953, 1997 | Phys.Rev.Lett.79:1953-1956,1997 | 10.1103/PhysRevLett.79.1953 | null | quant-ph | null | A scheme is proposed for protecting quantum states from both independent
decoherence and cooperative decoherence. The scheme operates by pairing each
qubit (two-state quantum system) with an ancilla qubit and by encoding the
states of the qubits into the corresponding coherence-preserving states of the
qubit-pairs. In this scheme, the amplitude damping (loss of energy) is
prevented as well as the phase damping (dephasing) by a strategy called the
free-Hamiltonian-elimination We further extend the scheme to include quantum
gate operations and show that loss and decoherence during the gate operations
can also be prevented.
| [
{
"version": "v1",
"created": "Sat, 22 Mar 1997 04:47:16 GMT"
},
{
"version": "v2",
"created": "Fri, 3 Oct 1997 08:52:56 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Duan",
"Lu-Ming",
"",
"University of Science and Technology\n of China"
],
[
"Guo",
"Guang-Can",
"",
"University of Science and Technology\n of China"
]
] |
quant-ph/9703041 | null | Scott Hill and William K. Wootters (Williams College) | Entanglement of a Pair of Quantum Bits | 10 pages | Phys.Rev.Lett.78:5022-5025,1997 | 10.1103/PhysRevLett.78.5022 | null | quant-ph | null | The ``entanglement of formation'' of a mixed state of a bipartite quantum
system can be defined in terms of the number of pure singlets needed to create
the state with no further transfer of quantum information. We find an exact
formula for the entanglement of formation for all mixed states of two qubits
having no more than two non-zero eigenvalues, and we report evidence suggesting
that the formula is valid for all states of this system.
| [
{
"version": "v1",
"created": "Sat, 22 Mar 1997 17:16:41 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Mar 1997 01:10:32 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Hill",
"Scott",
"",
"Williams College"
],
[
"Wootters",
"William K.",
"",
"Williams College"
]
] |
quant-ph/9703042 | Seth Lloyd | Seth Lloyd (MIT) | Quantum controllers for quantum systems | 10 pages, TeX | null | null | null | quant-ph | null | This paper discusses fully coherent quantum feedback control, in which the
sensors, controller, and actuators are quantum systems and interact coherently
with the system to be controlled: as a result, the entire feedback loop is
coherent. Unlike conventional semiclassical feedback control of quantum
systems, feedback control by quantum controllers is not stochastic, preserves
the initial state of the controlled system, and can control quantum systems in
ways that are not possible using conventional, incoherent feedback control. In
particular, the target state to which the quantum controller drives the system
can be entangled with another quantum system. This paper investigates quantum
controllers and states necessary and sufficient conditions for a Hamiltonian
quantum system to be observable and controllable by a quantum controller.
| [
{
"version": "v1",
"created": "Sun, 23 Mar 1997 20:54:50 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lloyd",
"Seth",
"",
"MIT"
]
] |
quant-ph/9703043 | Christopher A. Fuchs | Chistopher A. Fuchs (Caltech) | Nonorthogonal Quantum States Maximize Classical Information Capacity | 5 pages, REVTeX, mild extension of results, much improved
presentation, to appear in Physical Review Letters | Phys.Rev.Lett.79:1162-1165,1997 | 10.1103/PhysRevLett.79.1162 | null | quant-ph | null | I demonstrate that, rather unexpectedly, there exist noisy quantum channels
for which the optimal classical information transmission rate is achieved only
by signaling alphabets consisting of nonorthogonal quantum states.
| [
{
"version": "v1",
"created": "Mon, 24 Mar 1997 02:29:34 GMT"
},
{
"version": "v2",
"created": "Fri, 1 Aug 1997 01:21:03 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Fuchs",
"Chistopher A.",
"",
"Caltech"
]
] |
quant-ph/9703044 | Elisha Atzmon | E. Atzmon | The Associated Metric for a Particle in a Quantum Energy Level | 14 pages, latex, epsf, 3 figures. Some clarifications were added | Mod.Phys.Lett. A12 (1997) 3017-3026 | 10.1142/S0217732397003149 | TAUP-2414-97 | quant-ph gr-qc hep-th | null | We show that the probabilistic distribution over the space in the spectator
world, can be associated via noncommutative geometry (with some modifications)
to a metric in which the particle lives. According to this geometrical view,
the metric in the particle world is ``contracted'' or ``stretched'' in an
inverse proportion to the probability distribution.
| [
{
"version": "v1",
"created": "Mon, 24 Mar 1997 08:27:54 GMT"
},
{
"version": "v2",
"created": "Fri, 4 Jul 1997 08:00:41 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Atzmon",
"E.",
""
]
] |
quant-ph/9703045 | Lin Zhang | Lin Zhang and Ian Fuss (Defence Science and Technology Organisation,
Australia) | Quantum Reed-Muller Codes | 10 pages, LaTeX, 2 figures | null | null | DSTO/CD/QIT/9701 | quant-ph | null | This paper presents a set of quantum Reed-Muller codes which are typically
100 times more effective than existing quantum Reed-Muller codes.
| [
{
"version": "v1",
"created": "Mon, 24 Mar 1997 09:12:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zhang",
"Lin",
"",
"Defence Science and Technology Organisation,\n Australia"
],
[
"Fuss",
"Ian",
"",
"Defence Science and Technology Organisation,\n Australia"
]
] |
quant-ph/9703046 | Vladimir Buzek | V. Buzek, S.L. Braunstein, M. Hillery, and D. Bruss | Quantum copying: A network | 10 pages LaTeX, with 1 figure, submitted to the Physical Review A | null | 10.1103/PhysRevA.56.3446 | null | quant-ph | null | We present a network consisting of quantum gates which produces two imperfect
copies of an arbitrary qubit. The quality of the copies does not depend on the
input qubit. We also show that for a restricted class of inputs it is possible
to use a very similar network to produce three copies instead of two. For
qubits in this class, the copy quality is again independent of the input and is
the same as the quality of the copies produced by the two-copy network.
| [
{
"version": "v1",
"created": "Mon, 24 Mar 1997 12:11:03 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Buzek",
"V.",
""
],
[
"Braunstein",
"S. L.",
""
],
[
"Hillery",
"M.",
""
],
[
"Bruss",
"D.",
""
]
] |
quant-ph/9703047 | Kotel'nikov Gennadii | G. A. Kotel'nikov (RRC "Kurchatov Institute", Moscow, Russia) | On the Nature of Charge Conjugation in Quantum Theory | 6 pages, LaTeX, Report on the Conference of Nuclear Physics Division
of Russian Academy of Science "Fundamental Interactions of Elementary
Particles", ITEP, Moscow, October 23-27, 1995 | null | null | IAE-5910/1 | quant-ph | null | On the basis of the invariance of Dirac equation Lu(x,c)=0 with respect to
the inversion of the speed of light Q:(x,c)=(x,-c), it is shown that the
relationship [C,PTQ]u(x,c)=0 between the transformations of the charge
conjugation C, the space inversion P, the time reversal T and the inversion of
the speed of light Q is true. The charge conjugation in quantum theory may be
interpreted as the consequence of the discrete symmetries reflecting the
fundamental properties of space, time and speed of light.
| [
{
"version": "v1",
"created": "Tue, 25 Mar 1997 15:38:50 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kotel'nikov",
"G. A.",
"",
"RRC \"Kurchatov Institute\", Moscow, Russia"
]
] |
quant-ph/9703048 | Eric Rains | Eric M. Rains (AT&T Research) | Nonbinary quantum codes | 11 pages, AMSTeX | null | null | null | quant-ph | null | We present several results on quantum codes over general alphabets (that is,
in which the fundamental units may have more than 2 states). In particular, we
consider codes derived from finite symplectic geometry assumed to have
additional global symmetries. From this standpoint, the analogues of
Calderbank-Shor-Steane codes and of GF(4)-linear codes turn out to be special
cases of the same construction. This allows us to construct families of quantum
codes from certain codes over number fields; in particular, we get analogues of
quadratic residue codes, including a single-error correcting code encoding one
letter in five, for any alphabet size. We also consider the problem of
fault-tolerant computation through such codes, generalizing ideas of Gottesman.
| [
{
"version": "v1",
"created": "Tue, 25 Mar 1997 18:56:01 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Rains",
"Eric M.",
"",
"AT&T Research"
]
] |
quant-ph/9703049 | Mensky Michael B. | J\"urgen Audretsch, Michael Mensky | Continuous Fuzzy Measurement of Energy for a Two-Level System | 29 pages in LATEX, 1 figure in EPS, to be published in Physical
Review A | Phys.Rev. A56 (1997) 44 | 10.1103/PhysRevA.56.44 | null | quant-ph | null | A continuous measurement of energy which is sharp (perfect) leads to the
quantum Zeno effect (freezing of the state). Only if the quantum measurement is
fuzzy, continuous monitoring gives a readout E(t) from which information about
the dynamical development of the state vector of the system may be obtained in
certain cases. This is studied in detail. Fuzziness is thereby introduced with
the help of restricted path integrals equivalent to non-Hermitian Hamiltonians.
For an otherwise undisturbed multilevel system it is shown that this
measurement represents a model of decoherence. If it lasts long enough, the
measurement readout discriminates between the energy levels and the von Neumann
state reduction is obtained. For a two-level system under resonance influence
(which undergoes in absence of measurement Rabi oscillations between the
levels) different regimes of measurement are specified depending on its
duration and fuzziness: 1) the Zeno regime where the measurement results in a
freezing of the transitions between the levels and 2) the Rabi regime when the
transitions maintain. It is shown that in the Rabi regime at the border to the
Zeno regime a correlation exists between the time dependent measurement readout
and the modified Rabi oscillations of the state of the measured system.
Possible realizations of continuous fuzzy measurements of energy are sketched.
| [
{
"version": "v1",
"created": "Wed, 26 Mar 1997 19:46:37 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Audretsch",
"Jürgen",
""
],
[
"Mensky",
"Michael",
""
]
] |
quant-ph/9703050 | Nicolas Cerf | N. J. Cerf, S. E. Koonin (California Institute of Technology) | Monte Carlo Simulation of Quantum Computation | 12 pages Latex, 2 Postscript figures, to appear in Proceedings of the
IMACS (International Association for Mathematics and Computers in Simulation)
Conference on Monte Carlo Methods, Brussels, April 97 | Math. and Comp. in Simulation 47 (1998), 143-152 | null | KRL MAP-212 | quant-ph | null | The many-body dynamics of a quantum computer can be reduced to the time
evolution of non-interacting quantum bits in auxiliary fields by use of the
Hubbard-Stratonovich representation of two-bit quantum gates in terms of
one-bit gates. This makes it possible to perform the stochastic simulation of a
quantum algorithm, based on the Monte Carlo evaluation of an integral of
dimension polynomial in the number of quantum bits. As an example, the
simulation of the quantum circuit for the Fast Fourier Transform is discussed.
| [
{
"version": "v1",
"created": "Wed, 26 Mar 1997 19:55:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cerf",
"N. J.",
"",
"California Institute of Technology"
],
[
"Koonin",
"S. E.",
"",
"California Institute of Technology"
]
] |
quant-ph/9703051 | Scutaru Horia | Gh.- S. Paraoanu, Horia Scutaru | Bures distance between two displaced thermal states | 3 pages, RevTeX, no figures | Phys.Rev. A, 58, 869 (1998) | 10.1103/PhysRevA.58.869 | null | quant-ph | null | The Bures distance between two displaced thermal states and the corresponding
geometric quantities (statistical metric, volume element, scalar curvature) are
computed. Under nonunitary (dissipative) dynamics, the statistical distance
shows the same general features previously reported in the literature by
Braunstein and Milburn for two--state systems. The scalar curvature turns out
to have new interesting properties when compared to the curvature associated
with squeezed thermal states.
| [
{
"version": "v1",
"created": "Thu, 27 Mar 1997 09:22:39 GMT"
},
{
"version": "v2",
"created": "Mon, 9 Feb 1998 10:10:35 GMT"
},
{
"version": "v3",
"created": "Wed, 11 Feb 1998 06:56:03 GMT"
},
{
"version": "v4",
"created": "Thu, 12 Aug 1999 06:04:02 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Paraoanu",
"Gh. - S.",
""
],
[
"Scutaru",
"Horia",
""
]
] |
quant-ph/9703052 | null | Lorenza Viola, Roberto Onofrio and Tommaso Calarco | Macroscopic quantum damping in SQUID rings | 7 Pages; Plain REVTeX; 3 Figures available upon request; to be
published in Phys. Lett. A 229, 23 (1997) | Phys.Lett. A229 (1997) 23 | 10.1016/S0375-9601(97)00154-0 | null | quant-ph | null | The measurement process is introduced in the dynamics of Josephson devices
exhibiting quantum behaviour in a macroscopic degree of freedom. The
measurement is shown to give rise to a dynamical damping mechanism whose
experimental observability could be relevant to understand decoherence in
macroscopic quantum systems.
| [
{
"version": "v1",
"created": "Thu, 27 Mar 1997 11:16:30 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Viola",
"Lorenza",
""
],
[
"Onofrio",
"Roberto",
""
],
[
"Calarco",
"Tommaso",
""
]
] |
quant-ph/9703053 | J. Acacio de Barros | J. Acacio de Barros (UFJF), Gary Oas (Stanford University), Patrick
Suppes (Stanford University) | Can single-photon states violate causality? | This paper has been withdrawn | null | null | null | quant-ph | null | This paper has been withdrawn.
| [
{
"version": "v1",
"created": "Sat, 29 Mar 1997 22:14:40 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"de Barros",
"J. Acacio",
"",
"UFJF"
],
[
"Oas",
"Gary",
"",
"Stanford University"
],
[
"Suppes",
"Patrick",
"",
"Stanford University"
]
] |
quant-ph/9703054 | Daniel S. Abrams | Daniel S. Abrams (1), Seth Lloyd (2) ((1) Department of Physics,
Massachusetts Institute of Technology (2) Department of Mechanical
Engineering, Massachusetts Institute of Technology) | Simulation of Many-Body Fermi Systems on a Universal Quantum Computer | Submitted 11/7/96 to Phys. Rev. Lett. 10 pages, 0 figures | Phys.Rev.Lett. 79 (1997) 2586-2589 | 10.1103/PhysRevLett.79.2586 | null | quant-ph | null | We provide fast algorithms for simulating many body Fermi systems on a
universal quantum computer. Both first and second quantized descriptions are
considered, and the relative computational complexities are determined in each
case. In order to accommodate fermions using a first quantized Hamiltonian, an
efficient quantum algorithm for anti-symmetrization is given. Finally, a
simulation of the Hubbard model is discussed in detail.
| [
{
"version": "v1",
"created": "Fri, 28 Mar 1997 20:03:47 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Abrams",
"Daniel S.",
""
],
[
"Lloyd",
"Seth",
""
]
] |
quant-ph/9703055 | Tri Sulistiono | Tri Sulistiono | Notes on free fall of a particle and bouncing on a reflecting surface | 3 pages, no figures, uses LaTeX, typing in equation (1), (2), (6) and
(21) have been corrected, some references have been added | null | null | null | quant-ph | null | Considerable progress has recently been made in controling the motion of free
atomic particles by means of light pressure exerted by laser radiation. The
free fall of atoms and bouncing on a reflecting surface made from evanescent
wave formed by internal reflection of a quasiresonant laser beam at a curved
glass surface in the presence of homogeneous gravitational field has been
observed. In this paper we present the energy quantization of this system by
making use the asymptotic expansion method. It is shown that for large $n$ the
levels go like $n^{2/3}$ which may be compared with $n^2$ for the infinite
square well.
| [
{
"version": "v1",
"created": "Tue, 1 Apr 1997 00:38:31 GMT"
},
{
"version": "v2",
"created": "Tue, 1 Apr 1997 14:09:44 GMT"
},
{
"version": "v3",
"created": "Sun, 6 Apr 1997 10:43:54 GMT"
},
{
"version": "v4",
"created": "Fri, 18 Apr 1997 10:15:13 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Sulistiono",
"Tri",
""
]
] |
quant-ph/9704001 | Benni Reznik | Y. Aharonov and B. Reznik | Measurability in Linear and Non-Linear Quantum Mechanical Systems | 16 pages, Revtex | null | null | LAUR-97-186 | quant-ph gr-qc | null | The measurability by means of continuous measurements, of an observable
$\A(t_0)$, at an instant, and of a time averaged observable, $\bar \A=1/T\int
\A(t')dt'$, is examined for linear and in particular for non-linear quantum
mechanical systems. We argue that only when the exact (non-perturbative)
solution is known, an exact measurement may be possible. A perturbative
approach is shown to fail in the non-linear case for measurements with accuracy
$\Delta \bar \A < \Delta \bar \A_{min}(T)$, giving rise to a restriction on the
accuracy. Thus, in order to prepare an initial pure state of a non-linear
system, by means of a continuous measurement, the exact non-perturbative
solution must be known.
| [
{
"version": "v1",
"created": "Tue, 1 Apr 1997 19:30:25 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Aharonov",
"Y.",
""
],
[
"Reznik",
"B.",
""
]
] |
quant-ph/9704002 | Debbie Leung | D. W. Leung, M. A. Nielsen, I. L. Chuang, Y. Yamamoto | Approximate quantum error correction can lead to better codes | 7 pages, 2 figures, submitted to Phys. Rev. A | Phys.Rev.A56:2567-2573,1997 | 10.1103/PhysRevA.56.2567 | null | quant-ph | null | We present relaxed criteria for quantum error correction which are useful
when the specific dominant noise process is known. These criteria have no
classical analogue. As an example, we provide a four-bit code which corrects
for a single amplitude damping error. This code violates the usual Hamming
bound calculated for a Pauli description of the error process, and does not fit
into the GF(4) classification.
| [
{
"version": "v1",
"created": "Wed, 2 Apr 1997 06:38:07 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Leung",
"D. W.",
""
],
[
"Nielsen",
"M. A.",
""
],
[
"Chuang",
"I. L.",
""
],
[
"Yamamoto",
"Y.",
""
]
] |
quant-ph/9704003 | Cesar Miquel | Cesar Miquel, Juan Pablo Paz, Wojciech Hubert Zurek | Quantum computation with phase drift errors | 5 pages, RevTex, 2 figures | null | 10.1103/PhysRevLett.78.3971 | null | quant-ph | null | We present results of numerical simulations of the evolution of an ion trap
quantum computer made out of 18 ions which are subject to a sequence of nearly
15000 laser pulses in order to find the prime factors of N=15. We analyze the
effect of random and systematic phase drift errors arising from inaccuracies in
the laser pulses which induce over (under) rotation of the quantum state.
Simple analytic estimates of the tolerance for the quality of driving pulses
are presented. We examine the use of watchdog stabilization to partially
correct phase drift errors concluding that, in the regime investigated, it is
rather inefficient.
| [
{
"version": "v1",
"created": "Wed, 2 Apr 1997 13:02:17 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Miquel",
"Cesar",
""
],
[
"Paz",
"Juan Pablo",
""
],
[
"Zurek",
"Wojciech Hubert",
""
]
] |
quant-ph/9704004 | Olavo Leopoldino Da Silva Filho | L.S.F. Olavo | Quantum Mechanics as a Classical Theory XVI: Positive-Definite Densities | Plain Latex, 3 figures | null | null | UnB-016 | quant-ph | null | In this paper we will turn our attention to the problem of obtaining
phase-space probability density functions. We will show that it is possible to
obtain functions which assume only positive values over all its domain of
definition.
| [
{
"version": "v1",
"created": "Wed, 2 Apr 1997 18:50:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Olavo",
"L. S. F.",
""
]
] |
quant-ph/9704005 | null | D. Han, Y. S. Kim, and Marilyn E. Noz | O(3,3)-like Symmetries of Coupled Harmonic Oscillators | RevTeX, 24 pages, no figures, preliminary version in J. Math. Phys.
{\bf 36}, 3940 (1995) | null | null | null | quant-ph hep-th | null | In classical mechanics, the system of two coupled harmonic oscillators is
shown to possess the symmetry of the Lorentz group O(3,3) applicable to a
six-dimensional space consisting of three space-like and three time-like
coordinates, or SL(4,r) in the four-dimensional phase space consisting of two
position and two momentum variables. In quantum mechanics, the symmetry is
reduced to that of O(3,2) or Sp(4), which is a subgroup of O(3,3) or SL(4,r)
respectively. It is shown that among the six Sp(4)-like subgroups, only one
possesses the symmetry which can be translated into the group of unitary
transformations in quantum mechanics. In quantum mechanics, there is the lower
bound in the size of phase space for each mode determined by the uncertainty
principle while there are no restriction on the phase-space size in classical
mechanics. This is the reason why the symmetry is smaller in quantum mechanics.
| [
{
"version": "v1",
"created": "Thu, 3 Apr 1997 05:45:26 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Han",
"D.",
""
],
[
"Kim",
"Y. S.",
""
],
[
"Noz",
"Marilyn E.",
""
]
] |
quant-ph/9704006 | Werner Hofer | W. A. Hofer (TU Wien) | Measurement processes in quantum physics: a new theory of measurements
in terms of statistical ensembles | 24 pages (ReVTeX, twocolumn) and 9 figures (eps), corrected an
omission in eq.(5.4) and some typographical errors in section V-D (Quantum
erasers) | null | null | MW-97-02 | quant-ph | null | Considering the recently established arbitrariness the Schroedinger equation
has to be interpreted as an equation of motion for a statistical ensemble of
particles. The statistical qualities of individual particles derive from the
unknown intrinsic energy components, they depend on the physical environment by
way of external potentials. Due to these statistical qualities and wave
function normalization, non-locality is inherent to the fundamental relations
of Planck, de Broglie and Schroedinger. A local formulation of these statements
is introduced and briefly assessed, the modified and local Schroedinger
equation is non-linear. Quantum measurements are analyzed in detail, the exact
interplay between causal and statistical reasons in a measurement process can
be accounted for. Examples of individual measurement effects in quantum theory
are given, the treatment of diffraction experiments, neutron interferences,
quantum erasers, the quantum Zeno effect, and interaction-free measurements can
be described consistent with the suggested framework. The paper additionally
provides a strictly local and deterministic calculation of interactions in a
magnetic field. The results suggest that quantum theory is a statistical
formalism which derives its validity in measurements from considering every
possible measurement of a given system. It can equally be established, that the
framework of quantum physics is theoretically incomplete, because a
justification of ensemble qualities is not provided.
| [
{
"version": "v1",
"created": "Thu, 3 Apr 1997 09:26:39 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jun 1997 09:27:29 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Hofer",
"W. A.",
"",
"TU Wien"
]
] |
quant-ph/9704007 | null | Hideyasu Yamashita (Nagoya University) | Hyperfinite-operational Approach to the Problem of Time Reversibility of
Quantum Mechanics | 16 pages, LaTeX | null | null | null | quant-ph | null | This paper outlines a mathematical framework of quantum probability in which
the time asymmetry in describing measuring processes is avoided. The main
objects of the framework are hyperfinite operations, which are constructed by
using nonstandard analysis and the operational approach by Davies and Lewis.
Then the notions of Bayesian conditional probability are defined, and
Bayes-type theorems in terms of the probability are showed.
| [
{
"version": "v1",
"created": "Thu, 3 Apr 1997 16:03:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Yamashita",
"Hideyasu",
"",
"Nagoya University"
]
] |
quant-ph/9704008 | Tetsuya Shiromizu | Fumiaki Shibata, Masahiro Morikawa, Tetsuya Shiromizu and Masahide
Yamaguchi | Dissipative Quantum Tunneling from Quantum Potential Approach -- Back
Reaction of Particle Creation -- | 7 pages, 4 figures, LaTex | null | null | OCHA-PP-92 | quant-ph gr-qc hep-ph | null | Back reaction of the particle creation on the quantum tunneling process is
analyzed in real time formalism. We use quantum potential method in which whole
quantum dynamics is exactly projected to a classical Hamilton-Jacobi equation
with quantum corrections. We derive the reduction of the tunneling rate due to
this particle creation effect.
| [
{
"version": "v1",
"created": "Fri, 4 Apr 1997 06:30:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Shibata",
"Fumiaki",
""
],
[
"Morikawa",
"Masahiro",
""
],
[
"Shiromizu",
"Tetsuya",
""
],
[
"Yamaguchi",
"Masahide",
""
]
] |
quant-ph/9704009 | S. Karshenboim | Savely G. Karshenboim (D. I. Mendeleev Institute for Metrology) | Comments to On the Accuracy of Lamb Shift Measurements in Hydrogen
(Physica Scripta, 55 (1997) 33-40) by V. G. Pal'chikov, Yu. L. Sokolov, and
V. P. Yakovlev | 4 pages; [email protected] | Phys.Scripta 57 (1998) 213 | 10.1088/0031-8949/57/2/009 | null | quant-ph | null | The work is a comments on the article of V. G. Pal'chikov, Yu. L. Sokolov,
and V. P. Yakovlev, devoted to the measurement of the Lamb shift in the
hydrogen atom and published in Physica Scripta, 55 (1997) 33-40.
| [
{
"version": "v1",
"created": "Fri, 4 Apr 1997 17:46:21 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Karshenboim",
"Savely G.",
"",
"D. I. Mendeleev Institute for Metrology"
]
] |
quant-ph/9704010 | Vicente Delgado Borges | V. Delgado and J. G. Muga (Universidad de La Laguna) | Arrival time in quantum mechanics | 25 pages, LaTeX, no figures. A very minor correction to text | Phys. Rev. A 56, 3425 (1997) | 10.1103/PhysRevA.56.3425 | null | quant-ph | null | A self-adjoint operator with dimensions of time is explicitly constructed,
and it is shown that its complete and orthonormal set of eigenstates can be
used to define consistently a probability distribution of the time of arrival
at a spatial point.
| [
{
"version": "v1",
"created": "Fri, 4 Apr 1997 22:00:35 GMT"
},
{
"version": "v2",
"created": "Tue, 8 Apr 1997 20:39:36 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Delgado",
"V.",
"",
"Universidad de La Laguna"
],
[
"Muga",
"J. G.",
"",
"Universidad de La Laguna"
]
] |
quant-ph/9704011 | null | Kazuyuki Fujii and Kunio Funahasi | Extension of the Barut-Girardello Coherent State and Path Integral | 17 pages, LaTeX2e | J.Math.Phys. 38 (1997) 4422-4434 | 10.1063/1.532134 | null | quant-ph | null | We extend the Barut-Girardello coherent state for the representation of
$SU(1,1)$ to the coherent state for a representation of $U(N,1)$ and construct
the measure. We also construct a path integral formula for some Hamiltonian.
| [
{
"version": "v1",
"created": "Mon, 7 Apr 1997 07:51:37 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Fujii",
"Kazuyuki",
""
],
[
"Funahasi",
"Kunio",
""
]
] |
quant-ph/9704012 | Lov K. Grover | Lov K. Grover (Bell Labs, Murray Hill, NJ) | Quantum Telecomputation | Several minor improvements to the original paper; 11 pages, single
postscript file | null | null | null | quant-ph | null | Quantum mechanics permits certain kinds of non-local effects. This paper
demonstrates how these can be used for distributed computation with minimal
communication between various processors. The problem considered is that of
estimating the mean of N items to a certain precision. First a serial quantum
mechanical algorithm for this is presented that is faster than any classical
algorithm. Next it is shown how this can be efficiently parallelized with
quantum mechanical processors that are remotely located. These processors
consist of coupled EPR particles. Each processor has just to communicate one
bit of classical information to a central location at the end of its local
computation.
| [
{
"version": "v1",
"created": "Mon, 7 Apr 1997 18:38:52 GMT"
},
{
"version": "v2",
"created": "Mon, 21 Apr 1997 15:50:19 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Grover",
"Lov K.",
"",
"Bell Labs, Murray Hill, NJ"
]
] |
quant-ph/9704013 | Seth Lloyd | Seth Lloyd (MIT Mechanical Engineering) | A Greenberger-Horne-Zeilinger experiment for mixed states | 8 pages, TeX | null | null | null | quant-ph | null | This paper shows how the Greenberger-Horne-Zeilinger experiment, which
demonstrates the nonlocal nature of quantum mechanics, can be performed using
nuclear magnetic resonance on spins in molecules at finite temperature. The use
of nuclear magnetic resonance techniques allows the experiment to uncover the
nonlocality not just of special GHZ states, but of arbitrary three particle
states.
| [
{
"version": "v1",
"created": "Mon, 7 Apr 1997 22:54:15 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lloyd",
"Seth",
"",
"MIT Mechanical Engineering"
]
] |
quant-ph/9704014 | Feng Pan | Feng Pan and J. P. Draayer (Department of Physics & Astronomy,
Louisiana State University, Baton Rouge) | A complementary group technique for a resolution of the outer
multiplicity problem of SU(n): (I) Littlewood rule and a complementary group
of SU(n) | 15 pages, LaTeX | J.Math.Phys. 39 (1998) 5631-5641 | 10.1063/1.532555 | null | quant-ph | null | A complementary group to SU(n) is found that realizes all features of the
Littlewood rule for Kronecker products of SU(n) representations. This is
accomplished by considering a state of SU(n) to be a special Gel'fand state of
the complementary group {\cal U}(2n-2). The labels of {\cal U}(2n-2) can be
used as the outer multiplicity labels needed to distinguish multiple
occurrences of irreducible representations (irreps) in the SU(n)\times
SU(n)\downarrow SU(n) decomposition that is obtained from the Littlewood rule.
Furthermore, this realization can be used to determine SU(n)\supset
SU(n-1)\times U(1) Reduced Wigner Coefficients (RWCs) and Clebsch-Gordan
Coefficients (CGCs) of SU(n), using algebraic or numeric methods, in either the
canonical or a noncanonical basis. The method is recursive in that it uses
simpler RWCs or CGCs with one symmetric irrep in conjunction with standard
recoupling procedures. New explicit formulae for the multiplicity for SU(3) and
SU(4) are used to illustrate the theory.
| [
{
"version": "v1",
"created": "Tue, 8 Apr 1997 01:29:32 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Pan",
"Feng",
"",
"Department of Physics & Astronomy,\n Louisiana State University, Baton Rouge"
],
[
"Draayer",
"J. P.",
"",
"Department of Physics & Astronomy,\n Louisiana State University, Baton Rouge"
]
] |
quant-ph/9704015 | Feng Pan | Feng Pan and J. P. Draayer (Department of Physics & Astronomy,
Louisiana State University, Baton Rouge) | A complementary group technique for the resolution of the outer
multiplicity problem of SU(n): (II) A recoupling approach to the solution of
SU(3)\supset U(2) reduced Wigner coefficients | 30 pages, LaTeX | J.Math.Phys.39:5642-5662,1998 | 10.1063/1.532556 | null | quant-ph | null | A general procedure for the derivation of SU(3)\supset U(2) reduced Wigner
coefficients for the coupling (\lambda_{1}\mu_{1})\times
(\lambda_{2}\mu_{2})\downarrow (\lambda\mu)^{\eta}, where \eta is the outer
multiplicity label needed in the decomposition, is proposed based on a
recoupling approach according to the complementary group technique given in
(I). It is proved that the non-multiplicity-free reduced Wigner coefficients of
SU(n) are not unique with respect to canonical outer multiplicity labels, and
can be transformed from one set of outer multiplicity labels to another. The
transformation matrices are elements of SO(m), where m is the number of
occurrence of the corresponding irrep (\lambda\mu) in the decomposition
(\lambda_{1}\mu_{1})\times (\lambda_{2}\mu_{2})\downarrow (\lambda\mu). Thus, a
kind of the reduced Wigner coefficients with multiplicity is obtained after a
special SO(m) transformation. New features of this kind of reduced Wigner
coefficients and the differences from the reduced Wigner coefficients with
other choice of the multiplicity label given previously are discussed. The
method can also be applied to the derivation of general SU(n) Wigner or reduced
Wigner coefficients with multiplicity. Algebraic expression of another kind of
reduced Wigner coefficients, the so-called reduced auxiliary Wigner
coefficients for SU(3)\supset U(2), are also obtained.
| [
{
"version": "v1",
"created": "Tue, 8 Apr 1997 01:46:17 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Pan",
"Feng",
"",
"Department of Physics & Astronomy,\n Louisiana State University, Baton Rouge"
],
[
"Draayer",
"J. P.",
"",
"Department of Physics & Astronomy,\n Louisiana State University, Baton Rouge"
]
] |
quant-ph/9704016 | null | Lorenza Viola and Roberto Onofrio | Measured Quantum Dynamics of a Trapped Ion | 5 Pages, no figures; Plain REVTeX; to be published in the 1st May
issue of Phys. Rev. A, Rap. Commun. (1997) | null | 10.1103/PhysRevA.55.R3291 | null | quant-ph | null | The measurement process is taken into account in the dynamics of trapped ions
prepared in nonclassical motional states. The induced decoherence is shown to
manifest itself both in the inhibition of the internal population dynamics and
in a damping of the vibrational motion without classical counterpart.
Quantitative comparison with present experimental capabilities is discussed,
leading to a proposal for the verification of the predicted effects.
| [
{
"version": "v1",
"created": "Tue, 8 Apr 1997 13:40:59 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Viola",
"Lorenza",
""
],
[
"Onofrio",
"Roberto",
""
]
] |
quant-ph/9704017 | Armin Uhlmann | Armin Uhlmann | Entropy and optimal decompositions of states relative to a maximal
commutative subalgebra | 20 pages, latex, no figures. Some calculations and reasonings are
done in more detail. I have to thank an unknown referee for asking me to do
so. Misprints, if detected, are corrected. To be published in: Open Systems &
Information Dynamics | null | null | NTZ 9/97 (preprint, ZHS Leipzig) | quant-ph | null | To calculate the entropy of a subalgebra or of a channel with respect to a
state, one has to solve an intriguing optimalization problem. The latter is
also the key part in the entanglement of formation concept, in which case the
subalgebra is a subfactor. I consider some general properties, valid for these
definitions in finite dimensions, and apply them to a maximal commutative
subalgebra of a full matrix algebra. The main method is an interplay between
convexity and symmetry. A collection of helpful tools from convex analysis for
the problems in question is collected in an appendix.
| [
{
"version": "v1",
"created": "Tue, 8 Apr 1997 14:16:55 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Mar 1998 15:40:57 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Uhlmann",
"Armin",
""
]
] |
quant-ph/9704018 | V. P. Karasev | Valery P. Karassiov (P.N. Lebedev Physical Institute, Moscow) | Polynomial Lie Algebras and Associated Pseudogroup Structures in
Composite Quantum Models | 8 pages, LATEX | null | 10.1016/S0034-4877(97)85920-4 | LPI-97-03 | quant-ph | null | Polynomial Lie (super)algebras $g_{pd}$ are introduced via $G_{i}$-invariant
polynomial Jordan maps in quantum composite models with Hamiltonians $H$ having
invariance groups $G_{i}$. Algebras $g_{pd}$ have polynomial structure
functions in commutation relations, are related to pseudogroup structures $\exp
V, V\in g_{pd}$ and describe dynamic symmetry of models under study. Physical
applications of algebras $g_{pd}$ in quantum optics and in composite field
theories are briefly discussed.
| [
{
"version": "v1",
"created": "Wed, 9 Apr 1997 10:36:00 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Karassiov",
"Valery P.",
"",
"P.N. Lebedev Physical Institute, Moscow"
]
] |
quant-ph/9704019 | Farrokh Vatan | F. Vatan, V. P. Roychowdhury, M. P. Anantram | Spatially Correlated Qubit Errors and Burst-Correcting Quantum Codes | 15 pages, no figures, LaTeX. Updated version includes one more
example, also some minor errors are corrected | null | null | null | quant-ph | null | We explore the design of quantum error-correcting codes for cases where the
decoherence events of qubits are correlated. In particular, we consider the
case where only spatially contiguous qubits decohere, which is analogous to the
case of burst errors in classical coding theory. We present several different
efficient schemes for constructing families of such codes. For example, one can
find one-dimensional quantum codes of length n=13 and 15 that correct burst
errors of width b < 4; as a comparison, a random-error correcting quantum code
that corrects t=3 errors must have length n > 18. In general, we show that it
is possible to build quantum burst-correcting codes that have near optimal
dimension. For example, we show that for any constant b, there exist
b-burst-correcting quantum codes with length n, and dimension k=n-log n -O(b);
as a comparison, the Hamming bound for the case with t (constant) random errors
yields k < n - t log n - O(1) .
| [
{
"version": "v1",
"created": "Wed, 9 Apr 1997 22:22:48 GMT"
},
{
"version": "v2",
"created": "Fri, 16 May 1997 20:14:37 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Vatan",
"F.",
""
],
[
"Roychowdhury",
"V. P.",
""
],
[
"Anantram",
"M. P.",
""
]
] |
quant-ph/9704020 | Guo Guangcan | Lu-Ming Duan and Guang-Can Guo (University of Science and Technology
of China) | Two non-orthogonal states can be cloned by a unitary-reduction process | 9 pages, no figures, Latex | null | null | null | quant-ph | null | We show that, there are physical means for cloning two non-orthogonal pure
states which are secretly chosen from a certain set $% \$={ | \Psi_0 > , |
\Psi_1 > }$. The states are cloned through a unitary evolution together with a
measurement. The cloning efficiency can not attain 100%. With some negative
measurement results, the cloning fails.
| [
{
"version": "v1",
"created": "Thu, 10 Apr 1997 02:35:04 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Duan",
"Lu-Ming",
"",
"University of Science and Technology\n of China"
],
[
"Guo",
"Guang-Can",
"",
"University of Science and Technology\n of China"
]
] |
quant-ph/9704021 | Gian Carlo Ghirardi | E. Deotto and G.C. Ghirardi | Bohmian Mechanics Revisited | Latex, 34 pages, few typos corrected | Found.Phys. 28 (1998) 1-30 | 10.1023/A:1018752202576 | null | quant-ph | null | We consider the problem of whether there are deterministic theories
describing the evolution of an individual physical system in terms of the
definite trajectories of its constituent particles and which stay in the same
relation to Quantum Mechanics as Bohmian Mechanics but which differ from the
latter for what concerns the trajectories followed by the particles. Obviously,
one has to impose on the hypothetical alternative theory precise physical
requirements. We analyse various such constraints and we show step by step how
to meet them. This way of attacking the problem allows to recall and focus on
some relevant features of Bohm's theory. One of the central requirements we
impose on the models we are going to analyse has to do with their
transformation properties under the transformations of the extended Galilei
group. In a context like the one we are interested in one can put forward
various requests that we refer to as physical and genuine covariance and
invariance. Other fundamental requests are that the theory allows the
description of isolated physical systems as well as that it leads to a solution
(in the same sense as Bohmian Mechanics) of the measurement problem. We show
that there are infinitely many inequivalent (from the point of view of the
trajectories) bohmian-like theories reproducing the predictions of Quantum
Mechanics.
| [
{
"version": "v1",
"created": "Thu, 10 Apr 1997 15:55:57 GMT"
},
{
"version": "v2",
"created": "Thu, 24 Apr 1997 11:31:31 GMT"
},
{
"version": "v3",
"created": "Wed, 3 Sep 1997 14:14:52 GMT"
},
{
"version": "v4",
"created": "Thu, 25 Sep 1997 09:31:36 GMT"
},
{
"version": "v5",
"created": "Wed, 3 Apr 2002 18:42:31 GMT"
}
] | 2022-10-12T00:00:00 | [
[
"Deotto",
"E.",
""
],
[
"Ghirardi",
"G. C.",
""
]
] |
quant-ph/9704022 | Dr. Luca Salasnich, . D. | Luca Salasnich | On the Torus Quantization of Two Anyons with Coulomb Interaction in a
Magnetic Field | latex, 10 pages, to be published in Modern Physics Letters B | Mod.Phys.Lett. B11 (1997) 269-273 | 10.1142/S0217984997000335 | DFPD/97/TH/15, Universita` di Padova | quant-ph chao-dyn cond-mat hep-th nlin.CD | null | We study two anyons with Coulomb interaction in a uniform magnetic field $B$.
By using the torus quantization we obtain the modified Landau and Zeeman
formulas for the two anyons. Then we derive a simple algebraic equation for the
full spectral problem up to the second order in $B$.
| [
{
"version": "v1",
"created": "Thu, 10 Apr 1997 20:29:32 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Salasnich",
"Luca",
""
]
] |
quant-ph/9704023 | Ricardo Moritz Cavalcanti | R. M. Cavalcanti (PUC-Rio) | Comment on ``Resonant Spectra and the Time Evolution of the Survival and
Nonescape Probabilities'' | 1 page, REVTEX, submitted to Phys. Rev. Lett | Phys.Rev.Lett. 80 (1998) 4353 | 10.1103/PhysRevLett.80.4353 | null | quant-ph | null | In [G. Garcia-Calderon, J. L. Mateos, and M. Moshinsky, Phys. Rev. Lett. 74,
337 (1995)], the time evolution of the quantum decay of a state initially
located within an interaction region of finite range was investigated. In
particular, it was shown that the survival and nonescape probabilities behave
differently at very large times. The purpose of this Comment is to show that
they have the same asymptotic behavior.
| [
{
"version": "v1",
"created": "Fri, 11 Apr 1997 03:11:55 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Cavalcanti",
"R. M.",
"",
"PUC-Rio"
]
] |
quant-ph/9704024 | null | V.A. Skrebnev, R.N. Zaripov ( Kazan State University, Russian
Fedaration, Kazan) | Demonstration of the quantum mechanics applicability limits in time
reversion experiments in spin macrosystems | 23 pages, 5 figures | null | null | null | quant-ph | null | An experimental study of the applicability of mechanics equations to
describing the process of equilibrium establishing in an isolated spin system
was performed. The time-reversion effects were used at the experiments. It was
demonstrated, that the equations of mechanics do not describe the spin
macrosystem transition to the equilibrium. The experimental results correspond
to the theory which is based on the non-equilibrium thermodynamics methods and
takes into account the quick decay of cross-correlations in the systems.
| [
{
"version": "v1",
"created": "Mon, 14 Apr 1997 15:37:26 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Skrebnev",
"V. A.",
"",
"Kazan State University, Russian\n Fedaration, Kazan"
],
[
"Zaripov",
"R. N.",
"",
"Kazan State University, Russian\n Fedaration, Kazan"
]
] |
quant-ph/9704025 | Diosi Lajos | Lajos Diosi | Lorentz-covariant stochastic wave function dynamics? | withdrawal | null | null | null | quant-ph | null | The e-print is completely withdrawn for it was based on a report which was
not public. The author seriously apologizes because he was unaware.
| [
{
"version": "v1",
"created": "Mon, 14 Apr 1997 15:17:01 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Apr 1997 13:05:10 GMT"
},
{
"version": "v3",
"created": "Wed, 16 Apr 1997 16:55:42 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Diosi",
"Lajos",
""
]
] |
quant-ph/9704026 | null | Richard Cleve and Harry Buhrman | Substituting Quantum Entanglement for Communication | 4 pages REVTeX, no figures. Minor corrections | null | 10.1103/PhysRevA.56.1201 | null | quant-ph | null | We show that quantum entanglement can be used as a substitute for
communication when the goal is to compute a function whose input data is
distributed among remote parties. Specifically, we show that, for a particular
function among three parties (each of which possesses part of the function's
input), a prior quantum entanglement enables one of them to learn the value of
the function with only two bits of communication occurring among the parties,
whereas, without quantum entanglement, three bits of communication are
necessary. This result contrasts the well-known fact that quantum entanglement
cannot be used to simulate communication among remote parties.
| [
{
"version": "v1",
"created": "Mon, 14 Apr 1997 17:18:01 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Apr 1997 21:24:35 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Cleve",
"Richard",
""
],
[
"Buhrman",
"Harry",
""
]
] |
quant-ph/9704027 | Peter Hoyer | Gilles Brassard (Universite de Montreal), Peter Hoyer (Odense
University) | An Exact Quantum Polynomial-Time Algorithm for Simon's Problem | 12 pages, LaTeX2e, no figures. To appear in Proceedings of the Fifth
Israeli Symposium on Theory of Computing and Systems (ISTCS'97) | Fifth Israeli Symposium on Theory of Computing and Systems
(ISTCS'97), pp. 12-23, June 1997 | 10.1109/ISTCS.1997.595153 | null | quant-ph | null | We investigate the power of quantum computers when they are required to
return an answer that is guaranteed to be correct after a time that is
upper-bounded by a polynomial in the worst case. We show that a natural
generalization of Simon's problem can be solved in this way, whereas previous
algorithms required quantum polynomial time in the expected sense only, without
upper bounds on the worst-case running time. This is achieved by generalizing
both Simon's and Grover's algorithms and combining them in a novel way. It
follows that there is a decision problem that can be solved in exact quantum
polynomial time, which would require expected exponential time on any classical
bounded-error probabilistic computer if the data is supplied as a black box.
| [
{
"version": "v1",
"created": "Mon, 14 Apr 1997 23:15:05 GMT"
}
] | 2017-01-04T00:00:00 | [
[
"Brassard",
"Gilles",
"",
"Universite de Montreal"
],
[
"Hoyer",
"Peter",
"",
"Odense\n University"
]
] |
quant-ph/9704028 | Masanao Ozawa | Masanao Ozawa (Nagoya University) | Quantum Nondemolition Monitoring of Universal Quantum Computers | 5 pages, RevTeX, no figures, revised, to appear in Phys. Rev. Lett | Phys.Rev.Lett.80:631,1998 | 10.1103/PhysRevLett.80.631 | null | quant-ph | null | The halt scheme for quantum Turing machines, originally proposed by Deutsch,
is reformulated precisely and is proved to work without spoiling the
computation. The ``conflict'' pointed out recently by Myers in the definition
of a universal quantum computer is shown to be only apparent. In the context of
quantum nondemolition (QND) measurement, it is also shown that the output
observable, an observable representing the output of the computation, is a QND
observable and that the halt scheme is equivalent to the QND monitoring of the
output observable.
| [
{
"version": "v1",
"created": "Tue, 15 Apr 1997 10:15:02 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Nov 1997 11:31:52 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Ozawa",
"Masanao",
"",
"Nagoya University"
]
] |
quant-ph/9704029 | Igor V. Volovich | L.Accardi and I.V.Volovich | Quantum white noise with singular non-linear interaction | 8 pages, Latex | null | null | N.278, Roma University Tor Vergata | quant-ph hep-th | null | A model of a system driven by quantum white noise with singular quadratic
self--interaction is considered and an exact solution for the evolution
operator is found. It is shown that the renormalized square of the squeezed
classical white noise is equivalent to the quantum Poisson process. We describe
how equations driven by nonlinear functionals of white noise can be derived in
nonlinear quantum optics by using the stochastic approximation.
| [
{
"version": "v1",
"created": "Wed, 16 Apr 1997 09:08:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Accardi",
"L.",
""
],
[
"Volovich",
"I. V.",
""
]
] |
quant-ph/9704030 | Holger Hofmann | Holger F. Hofmann and Guenter Mahler | Measurement models for time-resolved spectroscopy: a comment | 14 pages RevTex, 4 figures | Quant.Semiclass.Opt. 7 (1995) 489-497 | 10.1088/1355-5111/7/4/006 | null | quant-ph physics.atom-ph physics.optics | null | We present an exactly solvable model for photon emission, which allows us to
examine the evolution of the photon wavefunction in space and time. We apply
this model to coherent phenomena in three-level systems with a special emphasis
on the photon detection process.
| [
{
"version": "v1",
"created": "Wed, 16 Apr 1997 12:26:19 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Hofmann",
"Holger F.",
""
],
[
"Mahler",
"Guenter",
""
]
] |
quant-ph/9704031 | David Craig | David Craig (University of Alberta) | The Geometry of Consistency: Decohering Histories in Generalized Quantum
Theory | 68 pages, RevTeX, 3 figures. PSNUP -2 strongly recommended | null | null | ALBERTA-THY-04-97, UCSB-TH-95-10 | quant-ph gr-qc | null | The geometry of decoherence in generalized "consistent histories" quantum
theory is explored, revealing properties of the theory that are independent of
any particular application of it. It is shown how the decoherence functional of
a closed quantum system may be regarded as an Hermitian form on the space of
linear operators on the Hilbert space of the system. This identification makes
manifest a number of structural properties of decoherence functionals. For
example, a bound on the maximum number of histories in a consistent set is
determined. When the decoherence functional is positive -- as in conventional
quantum mechanics -- it defines a semi-inner product on the space of history
operators. This shows that consistent sets of histories are just orthogonal
sets in this inner product. It further implies the existence in general of
Cauchy-Schwarz and triangle inequalities for positive decoherence functionals.
The geometrical significance of the ILS theorem classifying all possible
decoherence functionals is illuminated, and a version of the ILS theorem for
decoherence functionals on class operators is given. The class of history
operators consistent according to a given decoherence functional is found, and,
conversely, it is shown how to construct the decoherence functionals according
to which a given set of histories is consistent. More generally, the
"geometric" point of view here developed supplies a powerful unified language
with which to solve problems in generalized quantum theory.
| [
{
"version": "v1",
"created": "Thu, 17 Apr 1997 01:01:11 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Craig",
"David",
"",
"University of Alberta"
]
] |
quant-ph/9704032 | Lars M. Johansen | Lars M. Johansen | Equivalence between Bell's inequality and a constraint on stochastic
field theories for EPR states | 10 pages, 5 figures, accepted to Phys. Rev. A | Phys.Rev.A56:100-107,1997 | 10.1103/PhysRevA.56.100 | null | quant-ph | null | A generalized form of EPR state is defined, embracing both classical and
nonclassical states. It is shown that for such states, Bell's inequality is
equivalent to a constraint on stochastic field theories. Thus, violation of
Bell's inequality can be observed also for weak violation of stochastic field
theories. The Schrodinger cat state is shown to be an example of this.
| [
{
"version": "v1",
"created": "Thu, 17 Apr 1997 10:37:10 GMT"
}
] | 2011-08-17T00:00:00 | [
[
"Johansen",
"Lars M.",
""
]
] |
quant-ph/9704033 | Giacomo Mauro D'Ariano | Giacomo Mauro D'Ariano and Massimiliano Sacchi (Dipartimento di Fisica
'Alessandro Volta', Pavia, Italy) | Equivalence between squeezed-state and twin-beam communication channels | 15 pages. Two latex figures included. To appear on Modern Phys. Lett.
B | Modern Phys. Lett. B11, 1263 (1997). | 10.1142/S0217984997001511 | null | quant-ph | null | We show the equivalence between two different communication schemes that
employ a couple of modes of the electromagnetic field. One scheme uses
unconventional heterodyne detection, with correlated signal and image-band
modes in a twin-beam state from parametric downconversion. The other scheme is
realized through a complex-number coding over quadrature-squeezed states of two
uncorrelated modes, each detected by ordinary homodyning. This equivalence
concerns all the stages of the communication channel: the encoded state, the
optimal amplifier for the channel, the master equation modeling the loss, and
the output measurement scheme. The unitary transformation that connects the two
communication schemes is realized by a frequency conversion device.
| [
{
"version": "v1",
"created": "Thu, 17 Apr 1997 17:14:30 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Jan 1998 18:19:33 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"D'Ariano",
"Giacomo Mauro",
"",
"Dipartimento di Fisica\n 'Alessandro Volta', Pavia, Italy"
],
[
"Sacchi",
"Massimiliano",
"",
"Dipartimento di Fisica\n 'Alessandro Volta', Pavia, Italy"
]
] |
quant-ph/9704034 | Giacomo Mauro D'Ariano | Giacomo M. D'Ariano and Matteo G. A. Paris (Dipartimento di Fisica
'Alessandro Volta', Pavia, Italy) | Added noise in homodyne measurement of field-observables | Two figures. Submitted to Phys. Lett. A | Phys.Lett. A233 (1997) 49 | 10.1016/S0375-9601(97)00424-6 | null | quant-ph | null | Homodyne tomography provides a way for measuring generic field-operators.
Here we analyze the determination of the most relevant quantities: intensity,
field, amplitude and phase. We show that tomographic measurements are affected
by additional noise in comparison with the direct detection of each observable
by itself. The case of of coherent states has been analyzed in details and
earlier estimations of tomographic precision are critically discussed.
| [
{
"version": "v1",
"created": "Thu, 17 Apr 1997 17:14:29 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"D'Ariano",
"Giacomo M.",
"",
"Dipartimento di Fisica\n 'Alessandro Volta', Pavia, Italy"
],
[
"Paris",
"Matteo G. A.",
"",
"Dipartimento di Fisica\n 'Alessandro Volta', Pavia, Italy"
]
] |
quant-ph/9704035 | Larry Ford | L.H. Ford | Electromagnetic Vacuum Fluctuations and Electron Coherence II: Effects
of Wavepacket Size | 16 pages, Latex, 3 figures, uses epsf | Phys.Rev. A56 (1997) 1812-1818 | 10.1103/PhysRevA.56.1812 | TUTP-97-5 | quant-ph hep-th | null | If one analyzes the effects of electromagnetic vacuum fluctuations upon an
electron interference pattern in an approximation in which the electrons follow
classical trajectories, an ultraviolet divergence results. It is shown that
this divergence is an artifact of the classical trajectory approximation, and
is absent when the finite sizes of electron wavepackets are accounted for. It
is shown that the vacuum fluctuation effect has a logarithmic dependence upon
the wavepacket size. However, at least in one model geometry, this dependence
cancels when one includes both vacuum fluctuation and photon emission effects.
| [
{
"version": "v1",
"created": "Thu, 17 Apr 1997 17:05:23 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Ford",
"L. H.",
""
]
] |
quant-ph/9704036 | Tony Wong | R. Graham, T. Wong, M. J. Collett, S. M. Tan, and D. F. Walls | Phase preparation by atom counting of Bose-Einstein condensates in mixed
states | 9 pages, 6 PostScript figure, submitted to PRA | null | 10.1103/PhysRevA.57.493 | null | quant-ph | null | We study the build up of quantum coherence between two Bose-Einstein
condensates which are initially in mixed states. We consider in detail the two
cases where each condensate is initially in a thermal or a Poisson distribution
of atom number. Although initially there is no relative phase between the
condensates, a sequence of spatial atom detections produces an interference
pattern with arbitrary but fixed relative phase. The visibility of this
interference pattern is close to one for the Poisson distribution of two
condensates with equal counting rates but it becomes a stochastic variable in
the thermal case, where the visibility will vary from run to run around an
average visibility of $\pi /4.$ In both cases, the variance of the phase
distribution is inversely proportional to the number of atom detections in the
regime where this number is large compared to one but small compared with the
total number of atoms in the condensates.
| [
{
"version": "v1",
"created": "Fri, 18 Apr 1997 00:02:13 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Graham",
"R.",
""
],
[
"Wong",
"T.",
""
],
[
"Collett",
"M. J.",
""
],
[
"Tan",
"S. M.",
""
],
[
"Walls",
"D. F.",
""
]
] |
quant-ph/9704037 | M. Dakna | T. Opatrny, M. Dakna, and D.-G. Welsch | Number phase uncertainty relations: verification by homodyning | 1 Ps figure (divided in 3 subfigures) using REVTEX | null | 10.1103/PhysRevA.57.2129 | null | quant-ph | null | It is shown that fundamental uncertainty relations between photon number and
canonical phase of a single-mode optical field can be verified by means of
balanced homodyne measurement. All the relevant quantities can be sampled
directly from the measured phase-dependent quadrature distribution.
| [
{
"version": "v1",
"created": "Fri, 18 Apr 1997 08:59:37 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Opatrny",
"T.",
""
],
[
"Dakna",
"M.",
""
],
[
"Welsch",
"D. -G.",
""
]
] |
quant-ph/9704038 | Antoine Suarez | Antoine Suarez (Center for Quantum Philosophy, Zurich) and Valerio
Scarani (EPFL, Swiss Federal Institute of Technology, Lausanne) | Does entanglement depend on the timing of the impacts at the
beam-splitters? | 5 pages of Latex and 2 eps figures. Submitted to Phys. Lett. A | Phys.Lett. A232 (1997) 9-14 | 10.1016/S0375-9601(97)00346-0 | CQP-960924 | quant-ph | null | A new nonlocality experiment with moving beam-splitters is proposed. The
experiment is analysed according to conventional quantum mechanics, and to an
alternative nonlocal description in which superposition depends not only on
indistinguishability but also on the timing of the impacts at the
beam-splitters.
| [
{
"version": "v1",
"created": "Sat, 19 Apr 1997 12:05:35 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Suarez",
"Antoine",
"",
"Center for Quantum Philosophy, Zurich"
],
[
"Scarani",
"Valerio",
"",
"EPFL, Swiss Federal Institute of Technology, Lausanne"
]
] |
quant-ph/9704039 | Lech Jakobczyk | R. Gielerak, L. Jakobczyk, R.Olkiewicz | Stochastically positive structures on Weyl algebras. The case of
quasi-free states | 46 pages, amstex | J.Math.Phys. 39 (1998) 6291-6328 | 10.1063/1.532639 | null | quant-ph | null | We consider quasi-free stochastically positive ground and thermal states on
Weyl algebras in Euclidean time formulation. In particular, we obtain a new
derivation of a general form of thermal quasi-free state and give conditions
when such state is stochastically positive i.e. when it defines periodic
stochastic process with respect to Euclidean time, so called thermal process.
Then we show that thermal process completely determines modular structure
canonically associated with quasi-free state on Weyl algebra. We discuss a
variety of examples connected with free field theories on globally hyperbolic
stationary space-times and models of quantum statistical mechanics.
| [
{
"version": "v1",
"created": "Wed, 23 Apr 1997 13:00:29 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Gielerak",
"R.",
""
],
[
"Jakobczyk",
"L.",
""
],
[
"Olkiewicz",
"R.",
""
]
] |
quant-ph/9704040 | Hayashi Masahito | Masahito Hayashi (Kyoto University) | Asymptotics of Quantum Relative Entropy From Representation Theoretical
Viewpoint | LaTeX2e. 8 pages. The title was changed from "Asymptotic Attainment
for Quantum Relative Entropy" | J.Phys.A34:3413-3419,2001 | 10.1088/0305-4470/34/16/309 | null | quant-ph | null | In this paper it was proved that the quantum relative entropy $D(\sigma \|
\rho)$ can be asymptotically attained by Kullback Leibler divergences of
probabilities given by a certain sequence of POVMs. The sequence of POVMs
depends on $\rho$, but is independent of the choice of $\sigma$.
| [
{
"version": "v1",
"created": "Thu, 24 Apr 1997 08:29:36 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jun 1997 07:57:42 GMT"
},
{
"version": "v3",
"created": "Mon, 18 Aug 1997 06:16:57 GMT"
},
{
"version": "v4",
"created": "Thu, 11 Sep 1997 08:21:50 GMT"
},
{
"version": "v5",
"created": "Wed, 7 Apr 1999 02:42:46 GMT"
},
{
"version": "v6",
"created": "Wed, 22 Dec 1999 07:00:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hayashi",
"Masahito",
"",
"Kyoto University"
]
] |
quant-ph/9704041 | Hayashi Masahito | Masahito Hayashi | Asymptotic estimation theory for a finite dimensional pure state model | LaTeX, 23 pages, Doctoral Thesis | J.Phys.A31:4633-4655,1998 | 10.1088/0305-4470/31/20/006 | null | quant-ph | null | The optimization of measurement for n samples of pure sates are studied. The
error of the optimal measurement for n samples is asymptotically compared with
the one of the maximum likelihood estimators from n data given by the optimal
measurement for one sample.
| [
{
"version": "v1",
"created": "Thu, 24 Apr 1997 10:01:13 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Sep 1997 09:19:42 GMT"
},
{
"version": "v3",
"created": "Wed, 7 Apr 1999 03:03:24 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hayashi",
"Masahito",
""
]
] |
quant-ph/9704042 | Eric Rains | Eric M. Rains | Polynomial invariants of quantum codes | 10 pages, AMSTeX | null | null | null | quant-ph | null | The weight enumerators (quant-ph/9610040) of a quantum code are quite
powerful tools for exploring its structure. As the weight enumerators are
quadratic invariants of the code, this suggests the consideration of
higher-degree polynomial invariants. We show that the space of degree k
invariants of a code of length n is spanned by a set of basic invariants in
one-to-one correspondence with S_k^n. We then present a number of equations and
inequalities in these invariants; in particular, we give a higher-order
generalization of the shadow enumerator of a code, and prove that its
coefficients are nonnegative. We also prove that the quartic invariants of a
((4,4,2)) are uniquely determined, an important step in a proof that any
((4,4,2)) is additive ([2]).
| [
{
"version": "v1",
"created": "Thu, 24 Apr 1997 21:16:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Rains",
"Eric M.",
""
]
] |
quant-ph/9704043 | Eric Rains | Eric M. Rains | Quantum codes of minimum distance two | 13 pages, AMSTeX | null | null | null | quant-ph | null | It is reasonable to expect the theory of quantum codes to be simplified in
the case of codes of minimum distance 2; thus, it makes sense to examine such
codes in the hopes that techniques that prove effective there will generalize.
With this in mind, we present a number of results on codes of minimum distance
2. We first compute the linear programming bound on the dimension of such a
code, then show that this bound can only be attained when the code either is of
even length, or is of length 3 or 5. We next consider questions of uniqueness,
showing that the optimal code of length 2 or 4 is unique (implying that the
well-known one-qubit-in-five single-error correcting code is unique), and
presenting nonadditive optimal codes of all greater even lengths. Finally, we
compute the full automorphism group of the more important distance 2 codes,
allowing us to determine the full automorphism group of any GF(4)-linear code.
| [
{
"version": "v1",
"created": "Thu, 24 Apr 1997 20:57:28 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Rains",
"Eric M.",
""
]
] |
quant-ph/9704044 | Hayashi Masahito | Masahito Hayashi | A Linear Programming Approach to Attainable Cramer-Rao type Bounds and
Randomness Condition | LaTeX, 27 pages, submitted to Journal Mathematical Physics | null | null | null | quant-ph | null | The author studies the Cramer-Rao type bound by a linear programming
approach. By this approach, he found a necessary and sufficient condition that
the Cramer-Rao type bound is attained by a random measurement. In a spin 1/2
system, this condition is satisfied.
| [
{
"version": "v1",
"created": "Sun, 27 Apr 1997 11:53:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hayashi",
"Masahito",
""
]
] |
quant-ph/9704045 | Caroline Thompson | Caroline H. Thompson (Department of Computer Science, University of
Wales Aberystwyth) | Timing and Other Artifacts in EPR Experiments | 5 pages, LaTeX, 3 Encapsulated PostScript figures. Submitted 24:4:97
to Physical Review Letters. See also quant-ph/9611037 and other documents at
http://www.aber.ac.uk/~cat | null | null | null | quant-ph | null | Re-evaluation of the evidence (some of it unpublished) shows that
experimenters conducting Einstein-Podolsky-Bohm (EPR) experiments may have been
deceived by various pre-conceptions and artifacts. False or unproven
assumptions were made regarding, in some cases, fair sampling, in others
timing, accidental coincidences and enhancement. Realist possibilities,
assuming a purely wave model of light, are presented heuristically, and
suggestions given for fruitful lines of research. Quantum Mechanics can be
proved false, but Bell tests have turned out to be unsuitable for the task.
| [
{
"version": "v1",
"created": "Tue, 29 Apr 1997 13:05:25 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Thompson",
"Caroline H.",
"",
"Department of Computer Science, University of\n Wales Aberystwyth"
]
] |
quant-ph/9704046 | Werner Fischer | Werner Fischer, Thomas Hupfer, Hajo Leschke and Peter Mueller | Rigorous results on Schroedinger operators with certain Gaussian random
potentials in multi-dimensional continuous space | 9 pages | Updated version of a contribution to the conference proceedings
"Differential equations, asymptotic analysis, and mathematical physics,"
Eds.: M. Demuth and B.-W. Schulze, Akademie Verlag, Berlin (1997) pp. 105-112 | null | null | quant-ph | null | Schroedinger operators with certain Gaussian random potentials in
multi-dimensional Euclidean space possess almost surely an absolutely
continuous integrated density of states and no absolutely continuous spectrum
at sufficiently low energies.
| [
{
"version": "v1",
"created": "Wed, 30 Apr 1997 15:23:25 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fischer",
"Werner",
""
],
[
"Hupfer",
"Thomas",
""
],
[
"Leschke",
"Hajo",
""
],
[
"Mueller",
"Peter",
""
]
] |
quant-ph/9705001 | D. Trifonov | D.A. Trifonov (Institute for Nuclear Research, Sofia) | On the squeezed states for n observables | 25 pages, LaTex, 4 .pic and .ps figures. Improvements in text,
discussion on generation scheme added. To appear in Phys. Scripta | Phys.Scripta 58 (1998) 246-255 | 10.1088/0031-8949/58/3/009 | INRNE-TH-97/2 | quant-ph | null | Three basic properties (eigenstate, orbit and intelligence) of the canonical
squeezed states (SS) are extended to the case of arbitrary n observables. The
SS for n observables X_i can be constructed as eigenstates of their linear
complex combinations or as states which minimize the Robertson uncertainty
relation. When X_i close a Lie algebra L the generalized SS could also be
introduced as orbit of Aut(L^C). It is shown that for the nilpotent algebra h_N
the three generalizations are equivalent. For the simple su(1,1) the family of
eigenstates of uK_- + vK_+ (K_\pm being lowering and raising operators) is a
family of ideal K_1-K_2 SS, but it cannot be represented as an Aut(su^C(1,1))
orbit although the SU(1,1) group related coherent states (CS) with symmetry are
contained in it.
Eigenstates |z,u,v,w;k> of general combination uK_- + vK_+ + wK_3 of the
three generators K_j of SU(1,1) in the representations with Bargman index k =
1/2,1, ..., and k = 1/4,3/4 are constructed and discussed in greater detail.
These are ideal SS for K_{1,2,3}. In the case of the one mode realization of
su(1,1) the nonclassical properties (sub-Poissonian statistics, quadrature
squeezing) of the generalized even CS |z,u,v;+> are demonstrated. The states
|z,u,v,w;k=1/4,3/4> can exhibit strong both linear and quadratic squeezing.
| [
{
"version": "v1",
"created": "Thu, 1 May 1997 16:08:31 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Nov 1997 09:27:45 GMT"
},
{
"version": "v3",
"created": "Fri, 5 Jun 1998 15:18:27 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Trifonov",
"D. A.",
"",
"Institute for Nuclear Research, Sofia"
]
] |
quant-ph/9705002 | Alain Tapp | Gilles Brassard (1), Peter Hoyer (2), Alain Tapp (1) ((1) Universite
de Montreal, (2) Odense University) | Quantum Algorithm for the Collision Problem | 8 pages, LaTeX2e | Third Latin American Symp. on Theoretical Informatics (LATIN'98),
pp. 163-169, 1998. LNCS 1380 | 10.1007/BFb0054319 | null | quant-ph | null | In this note, we give a quantum algorithm that finds collisions in arbitrary
r-to-one functions after only O((N/r)^(1/3)) expected evaluations of the
function. Assuming the function is given by a black box, this is more efficient
than the best possible classical algorithm, even allowing probabilism. We also
give a similar algorithm for finding claws in pairs of functions. Furthermore,
we exhibit a space-time tradeoff for our technique. Our approach uses Grover's
quantum searching algorithm in a novel way.
| [
{
"version": "v1",
"created": "Thu, 1 May 1997 21:59:56 GMT"
}
] | 2017-01-10T00:00:00 | [
[
"Brassard",
"Gilles",
""
],
[
"Hoyer",
"Peter",
""
],
[
"Tapp",
"Alain",
""
]
] |
quant-ph/9705003 | Michal Horodecki | Michal Horodecki and Ryszard Horodecki | Are there basic laws of quantum information processing? | RevTeX, 16 pages, the proof of the theorem has been written
mathematically; the possible interpretation of the result (basing on the
analogy with thermodynamics) has been added; the previous discussion has been
removed | Phys.Lett. A244 (1998) 473-481 | 10.1016/S0375-9601(98)00408-3 | null | quant-ph | null | We prove within the standard quantum formalism without reduction postulate
that the no-cloning theorem and the principle of no-increasing of entanglement
under local actions and one-way classical communication are equivalent. We
argue that the result is a manifestation of more general principles governing
quantum information processing analogous to the thermodynamical laws.
| [
{
"version": "v1",
"created": "Tue, 6 May 1997 08:22:46 GMT"
},
{
"version": "v2",
"created": "Mon, 7 Jul 1997 14:00:42 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Horodecki",
"Michal",
""
],
[
"Horodecki",
"Ryszard",
""
]
] |
quant-ph/9705004 | Vladimir Manko | O. V. Man'ko and N. V. Tcherniega | Photon Distribution Function for Stocks Wave for Stimulatted Raman
Scattering | LATEX, 17 pages, accepted for publication in Journal of Russian Laser
Research (Plenum Press, New York), Volume 18, Number 4, 1997 | null | null | null | quant-ph | null | New time-dependent integrals of motion are found for stimulated Raman
scattering. Explicit formula for the photon-number probability distribution as
a function of the laser-field intensity and the medium parameters is obtained
in terms of Hermite polynomials of two variables.
| [
{
"version": "v1",
"created": "Tue, 6 May 1997 17:18:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Man'ko",
"O. V.",
""
],
[
"Tcherniega",
"N. V.",
""
]
] |
quant-ph/9705005 | Jonathan Halliwell | J. J. Halliwell (Imperial College, London) | Effective Theories of Coupled Classical and Quantum Variables from
Decoherent Histories: A New Approach to the Backreaction Problem | 27 pages, plain Tex | Phys. Rev. D 57, 2337 (1998) | 10.1103/PhysRevD.57.2337 | Imperial College preprint 96-97/45 (with revised settings for \vsize
and \voffset to accommodate US paper size) | quant-ph gr-qc | null | We use the decoherent histories approach to quantum theory to derive the form
of an effective theory describing the coupling of classical and quantum
variables. The derivation is carried out for a system consisting of a large
particle coupled to a small particle with the important additional feature that
the large particle is also coupled to a thermal environment producing the
decoherence necessary for classicality. The effective theory is obtained by
tracing out both the environment and the small particle variables. It consists
of a formula for the probabilities of a set of histories of the large particle,
and depends on the dynamics and initial quantum state of the small particle. It
has the form of an almost classical particle coupled to a stochastic variable
whose probabilities are determined by a formula very similar to that given by
quantum measurement theory for continuous measurements of the small particle's
position. The effective theory gives intuitively sensible answers when the
small particle is in a superposition of localized states.
| [
{
"version": "v1",
"created": "Tue, 6 May 1997 19:03:02 GMT"
},
{
"version": "v2",
"created": "Thu, 8 May 1997 15:26:04 GMT"
}
] | 2016-08-25T00:00:00 | [
[
"Halliwell",
"J. J.",
"",
"Imperial College, London"
]
] |
quant-ph/9705006 | Anders Karlsson | Anders Karlsson, Gunnar Bjork and Erik Forsberg (Laboratory of
Photonics and Microwave Engineering, Department of Electronics, Royal
Institute of Technology (KTH), Kista, Sweden) | Interaction-Free Measurements, Atom Localisation and Complementarity | 4 pages REVTEX, one eps file with 4 figures | null | null | null | quant-ph | null | We analyse interaction-free measurements on classical and quantum objects. We
show the transition from a classical interaction free measurement to a quantum
non-demolition measurement of atom number, and discuss the mechanism of the
enforcement of complementarity in atom interferometric interaction-free
measurements.
| [
{
"version": "v1",
"created": "Wed, 7 May 1997 10:29:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Karlsson",
"Anders",
"",
"Laboratory of\n Photonics and Microwave Engineering, Department of Electronics, Royal\n Institute of Technology"
],
[
"Bjork",
"Gunnar",
"",
"Laboratory of\n Photonics and Microwave Engineering, Department of Electronics, Royal\n Institute of Technology"
],
[
"Forsberg",
"Erik",
"",
"Laboratory of\n Photonics and Microwave Engineering, Department of Electronics, Royal\n Institute of Technology"
]
] |
quant-ph/9705007 | Park daegil | D.K.Park, Sahng-Kyoon Yoo, Soo-Young Lee, Jae-Rok Kahng, Chang Soo
Park, Eui-Soon Yim, and C.H.Lee | Propagator for an Aharonov-Bohm-Coulomb system | 10 pages, some statements are corrected | J.KoreanPhys.Soc.33:745-749,1998 | null | null | quant-ph | null | The propagator of three-dimensional Aharonov-Bohm-Coulomb system is
calculated by following the Duru-Kleinert method. It is shown that the system
is reduced to two independent two dimensional Aharonov-Bohm plus harmonic
oscillator systems through dimensional extension and Kustaanheimo-Stiefel
transformation. The energy spectrum is deduced.
| [
{
"version": "v1",
"created": "Wed, 7 May 1997 10:15:35 GMT"
},
{
"version": "v2",
"created": "Wed, 2 Jul 1997 04:37:15 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Park",
"D. K.",
""
],
[
"Yoo",
"Sahng-Kyoon",
""
],
[
"Lee",
"Soo-Young",
""
],
[
"Kahng",
"Jae-Rok",
""
],
[
"Park",
"Chang Soo",
""
],
[
"Yim",
"Eui-Soon",
""
],
[
"Lee",
"C. H.",
""
]
] |
quant-ph/9705008 | Jonathan Halliwell | L. Diosi and J. J. Halliwell | Coupling Classical and Quantum Variables using Continuous Quantum
Measurement Theory | 11 pages, plain Tex (with revised settings for \vsize and \voffset to
accommodate US paper sizes) | Phys.Rev.Lett. 81 (1998) 2846-2849 | 10.1103/PhysRevLett.81.2846 | Imperial College preprint 96-97/46 | quant-ph gr-qc | null | We propose a system of equations to describe the interaction of a
quasiclassical variable $X$ with a set of quantum variables $x$ that goes
beyond the usual mean field approximation. The idea is to regard the quantum
system as continuously and imprecisely measured by the classical system. The
effective equations of motion for the classical system therefore consist of
treating the quantum variable $x$ as a stochastic c-number $\x (t) $ the
probability distibution for which is given by the theory of continuous quantum
measurements. The resulting theory is similar to the usual mean field equations
(in which $x$ is replaced by its quantum expectation value) but with two
differences: a noise term, and more importantly, the state of the quantum
subsystem evolves according to the stochastic non-linear Schrodinger equation
of a continuously measured system. In the case in which the quantum system
starts out in a superposition of well-separated localized states, the classical
system goes into a statistical mixture of trajectories, one trajectory for each
individual localized state.
| [
{
"version": "v1",
"created": "Wed, 7 May 1997 13:08:57 GMT"
},
{
"version": "v2",
"created": "Thu, 8 May 1997 15:22:17 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Diosi",
"L.",
""
],
[
"Halliwell",
"J. J.",
""
]
] |
quant-ph/9705009 | David DiVincenzo | David P. DiVincenzo | Quantum Gates and Circuits | Latex, 18 pages, 12 figures. For the Proceedings of the ITP
Conference on Quantum Coherence and Decoherence, December, 1996, Proc. R.
Soc. London A | null | 10.1098/rspa.1998.0159 | null | quant-ph | null | A historical review is given of the emergence of the idea of the quantum
logic gate from the theory of reversible Boolean gates. I highlight the quantum
XOR or controlled NOT as the fundamental two-bit gate for quantum computation.
This gate plays a central role in networks for quantum error correction.
| [
{
"version": "v1",
"created": "Wed, 7 May 1997 15:51:34 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"DiVincenzo",
"David P.",
""
]
] |
quant-ph/9705010 | Arno Bohm | A. Bohm, M. Loewe, P. Patuleanu and C. Puntmann (Department of
Physics, University of Texas at Austin) | Jordan Blocks and Exponentially Decaying Higher Order Gamow States | Dedicated to L. P. Horwitz on the occasion of his 65th birthday; 11
pages, no figures, uses subeqnarray.sty; to appear in Found. of Phys. May 97 | null | 10.1007/BF02550171 | UTEXAS-HEP-96-26 Bohm-141 | quant-ph | null | In the framework of the rigged Hilbert space, unstable quantum systems
associated with first order poles of the analytically continued S-matrix can be
described by Gamow vectors which are generalized vectors with exponential decay
and a Breit-Wigner energy distribution. This mathematical formalism can be
generalized to quasistationary systems associated with higher order poles of
the S-matrix, which leads to a set of Gamow vectors of higher order with a
non-exponential time evolution. One can define a state operator from the set of
higher order Gamow vectors which obeys the exponential decay law. We shall
discuss to what extend the requirement of an exponential time evolution
determines the form of the state operator for a quasistationary microphysical
system associated with a higher order pole of the S-matrix.
| [
{
"version": "v1",
"created": "Wed, 7 May 1997 20:32:40 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Bohm",
"A.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Loewe",
"M.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Patuleanu",
"P.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Puntmann",
"C.",
"",
"Department of\n Physics, University of Texas at Austin"
]
] |
quant-ph/9705011 | Arno Bohm | A. Bohm, M. Loewe, S. Maxson, P. Patuleanu, C. Puntmann (Department of
Physics, University of Texas at Austin), and M. Gadella (Faculdad de
Ciensias, Universidad de Valladolid) | Gamow-Jordan Vectors and Non-Reducible Density Operators from Higher
Order S-Matrix Poles | 39 pages, 3 PostScript figures; sub2.eps may stall some printers and
should then be printed out separately; ghostview is o.k | J.Math.Phys. 38 (1997) 6072-6100 | 10.1063/1.532203 | UTEXAS-HEP-96-24 Bohm-139 | quant-ph | null | In analogy to Gamow vectors that are obtained from first order resonance
poles of the S-matrix, one can also define higher order Gamow vectors which are
derived from higher order poles of the S-matrix. An S-matrix pole of r-th order
at z_R=E_R-i\Gamma/2 leads to r generalized eigenvectors of order k= 0, 1, ...
, r-1, which are also Jordan vectors of degree (k+1) with generalized
eigenvalue (E_R-i\Gamma/2). The Gamow-Jordan vectors are elements of a
generalized complex eigenvector expansion, whose form suggests the definition
of a state operator (density matrix) for the microphysical decaying state of
this higher order pole. This microphysical state is a mixture of non-reducible
components. In spite of the fact that the k-th order Gamow-Jordan vectors has
the polynomial time-dependence which one always associates with higher order
poles, the microphysical state obeys a purely exponential decay law.
| [
{
"version": "v1",
"created": "Wed, 7 May 1997 22:10:43 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Bohm",
"A.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Loewe",
"M.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Maxson",
"S.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Patuleanu",
"P.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Puntmann",
"C.",
"",
"Department of\n Physics, University of Texas at Austin"
],
[
"Gadella",
"M.",
"",
"Faculdad de\n Ciensias, Universidad de Valladolid"
]
] |
quant-ph/9705012 | Christoph Puntmann | C. Puntmann and P. Patuleanu (Dept. of Physics, Univ. of Texas,
Austin) | Resonances from Higher Order S-Matrix Poles with Exponential Decay | 4 pages, no figures, uses group21.sty (included); to appear in
GROUP21 proceedings vol. 1, H.-D. Doebner et al., eds., World Scientific,
Singapore | null | null | UTEXAS-HEP-97-8 | quant-ph | null | In analogy to Gamow vectors describing resonance states from first order
S-matrix poles, one can define Gamow vectors from higher order poles of the
S-matrix. With these vectors we are going to discuss a density operator that
describes exponentially decaying resonances from higher order poles.
| [
{
"version": "v1",
"created": "Thu, 8 May 1997 00:16:42 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Puntmann",
"C.",
"",
"Dept. of Physics, Univ. of Texas,\n Austin"
],
[
"Patuleanu",
"P.",
"",
"Dept. of Physics, Univ. of Texas,\n Austin"
]
] |
quant-ph/9705013 | Christoph Puntmann | Christoph Puntmann | Higher Order Gamow States with Exponential Decay | 19 pages, no figures; proceedings of Peyresq/France, Summer 96 | Int.J.Theor.Phys. 36 (1997) 2295-2314 | 10.1007/BF02768926 | UTEXAS-HEP-97-9 | quant-ph | null | We derive Gamow vectors from S-matrix poles of higher multiplicity in analogy
to the Gamow vectors describing resonances from first-order poles. With these
vectors we construct a density operator that describes resonances associated
with higher order poles that obey an exponential decay law. It turns out that
this operator formed by these higher order Gamow vectors has a unique
structure.
| [
{
"version": "v1",
"created": "Thu, 8 May 1997 01:12:45 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Puntmann",
"Christoph",
""
]
] |
quant-ph/9705014 | Cassius D'Helon | C. D'Helon and G.J.Milburn | Quantum measurements with a quantum computer | 9 pages, 3 figures; RevTex | null | null | null | quant-ph | null | We present a scheme in which an ion trap quantum computer can be used to make
arbitrarily accurate measurements of the quadrature phase variables for the
collective vibrational motion of the ion. The electronic states of the ion
become the `apparatus', and the method is based on regarding the `apparatus' as
a quantum computer register which can be prepared in appropriate states by
running a Fourier transform algorithm on the data stored within it. The
resolution of the measurement rises exponentially with the number of ions used.
| [
{
"version": "v1",
"created": "Thu, 8 May 1997 03:05:21 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"D'Helon",
"C.",
""
],
[
"Milburn",
"G. J.",
""
]
] |
quant-ph/9705015 | null | Roberto Onofrio and Lorenza Viola | Lindblad Approach to Nonlinear Jaynes-Cummings Dynamics of a Trapped Ion | 5 Pages, 3 figures available upon request; Plain REVTeX; to be
published in Physical Review A | null | 10.1103/PhysRevA.56.39 | null | quant-ph | null | The Lindblad approach to open quantum systems is introduced for studying the
dynamics of a single trapped ion prepared in nonclassical motional states and
subjected to continuous measurement of its internal population. This results in
an inhibition of the dynamics similar to the one occurring in the quantum Zeno
effect. In particular, modifications to the Jaynes-Cummings collapses and
revivals arising from an initial coherent state of motion in various regimes of
interaction with the driving laser are dealt in detail.
| [
{
"version": "v1",
"created": "Fri, 9 May 1997 21:37:48 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Onofrio",
"Roberto",
""
],
[
"Viola",
"Lorenza",
""
]
] |
quant-ph/9705016 | Ruediger Schack | Ruediger Schack (Royal Holloway, University of London) | Using a quantum computer to investigate quantum chaos | 4 pages, REVTEX, no figures | Phys.Rev.A57:1634-1635,1998 | 10.1103/PhysRevA.57.1634 | null | quant-ph chao-dyn nlin.CD | null | We show that the quantum baker's map, a prototypical map invented for
theoretical studies of quantum chaos, has a very simple realization in terms of
quantum gates. Chaos in the quantum baker's map could be investigated
experimentally on a quantum computer based on only 3 qubits.
| [
{
"version": "v1",
"created": "Sat, 10 May 1997 16:35:02 GMT"
}
] | 2008-12-30T00:00:00 | [
[
"Schack",
"Ruediger",
"",
"Royal Holloway, University of London"
]
] |
quant-ph/9705017 | Yu Shi | Yu Shi | Synchronizing Quantum Paths of a Universal Quantum Computer | This paper has been withdrawn, and will be superseded by another
submission | null | null | null | quant-ph | null | This paper has been withdrawn, and will be superseded by another submission.
| [
{
"version": "v1",
"created": "Sat, 10 May 1997 18:54:42 GMT"
},
{
"version": "v2",
"created": "Tue, 13 May 1997 10:08:17 GMT"
},
{
"version": "v3",
"created": "Tue, 19 May 1998 10:56:15 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Shi",
"Yu",
""
]
] |
quant-ph/9705018 | Guo Guangcan | Lu-Ming Duan and Guang-Can Guo (University of Science and Technology
of China) | Linearly-independent quantum states can be cloned | 9 pages, no figures, Latex | null | null | null | quant-ph | null | A fundamental question in quantum mechanics is, whether it is possible to
replicate an arbitrary unknown quantum state. Then famous quantum no-cloning
theorem [Nature 299, 802 (1982)] says no to the question. But it leaves open
the following question: If the state is not arbitrary, but secretly chosen from
a certain set $\$={ | \Psi _1> ,| \Psi_2> ,... ,| \Psi _n> } $, whether is the
cloning possible? This question is of great practical significance because of
its applications in quantum information theory. If the states $| \Psi_1>, |
\Psi_2>,...$ and $| \Psi_n> $ are linearly-dependent, similar to the proof of
the no-cloning theorem, the linearity of quantum mechanics forbids such
replication. In this paper, we show that, if the states $| \Psi_1>, | \Psi _2>,
...$ and $| \Psi_n> $ are linearly-independent, they do can be cloned by a
unitary-reduction process.
| [
{
"version": "v1",
"created": "Mon, 12 May 1997 03:18:55 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Duan",
"Lu-Ming",
"",
"University of Science and Technology\n of China"
],
[
"Guo",
"Guang-Can",
"",
"University of Science and Technology\n of China"
]
] |
quant-ph/9705019 | Samuel Joseph | Joseph Samuel | The Geometric Phase and Ray Space Isometries | 17 pages, Latex file, no figures, To appear in Pramana J. Phys | null | 10.1007/BF02847455 | null | quant-ph | null | We study the behaviour of the geometric phase under isometries of the ray
space. This leads to a better understanding of a theorem first proved by
Wigner: isometries of the ray space can always be realised as projections of
unitary or anti-unitary transformations on the Hilbert space. We suggest that
the construction involved in Wigner's proof is best viewed as an use of the
Pancharatnam connection to ``lift'' a ray space isometry to the Hilbert space.
| [
{
"version": "v1",
"created": "Mon, 12 May 1997 06:50:09 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Samuel",
"Joseph",
""
]
] |
quant-ph/9705020 | Giacomo Mauro D'Ariano | G. M. D'Ariano and M. F. Sacchi (Dipartimento di Fisica 'Alessandro
Volta', Pavia, Italy) | Trace forms for the generalized Wigner functions | Accepted on Nuovo Cimento B | Nuovo Cim. B112 (1997) 881-888 | null | null | quant-ph | null | We derive simple formulas connecting the generalized Wigner functions for
$s$-ordering with the density matrix, and vice-versa. These formulas proved
very useful for quantum mechanical applications, as, for example, for
connecting master equations with Fokker-Planck equations, or for evaluating the
quantum state from Monte Carlo simulations of Fokker-Planck equations, and
finally for studying positivity of the generalized Wigner functions in the
complex plane.
| [
{
"version": "v1",
"created": "Mon, 12 May 1997 14:10:43 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"D'Ariano",
"G. M.",
"",
"Dipartimento di Fisica 'Alessandro\n Volta', Pavia, Italy"
],
[
"Sacchi",
"M. F.",
"",
"Dipartimento di Fisica 'Alessandro\n Volta', Pavia, Italy"
]
] |
quant-ph/9705021 | Giacomo Mauro D'Ariano | G. M. D'Ariano and M. F. Sacchi (Dipartimento di Fisica 'Alessandro
Volta', Pavia, Italy) | Optical von Neumann measurement | One latex figure. Accepted on Phys. Lett. A | Phys.Lett. A231 (1997) 325-330 | 10.1016/S0375-9601(97)00314-9 | null | quant-ph | null | We present an optical scheme that realizes the standard von Neumann
measurement model, providing an indirect measurement of a quadrature of the
field with controllable Gaussian state-reduction. The scheme is made of simple
optical elements, as laser sources, beam splitters, and phase sensitive
amplifiers, along with a feedback mechanism that uses a Pockels cell. We show
that the von Neumann measurement is achieved without the need of working in a
ultra-short pulsed regime.
| [
{
"version": "v1",
"created": "Mon, 12 May 1997 14:10:44 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"D'Ariano",
"G. M.",
"",
"Dipartimento di Fisica 'Alessandro\n Volta', Pavia, Italy"
],
[
"Sacchi",
"M. F.",
"",
"Dipartimento di Fisica 'Alessandro\n Volta', Pavia, Italy"
]
] |
quant-ph/9705022 | Wayne M. Itano | D. J. Wineland, C. Monroe, D. M. Meekhof, B. E. King, D. Leibfried, W.
M. Itano, J. C. Bergquist, D. Berkeland, J. J. Bollinger, J. Miller | Quantum state manipulation of trapped atomic ions | Postscript only. 21 pages text, 5 figures., Proc. Workshop on Quantum
Computing, Santa Barbara, CA, Dec. 1996, Submitted to Proc. Roy. Soc. A | null | 10.1098/rspa.1998.0168 | null | quant-ph | null | A single laser-cooled and trapped 9Be+ ion is used to investigate methods of
coherent quantum-state synthesis and quantum logic. We create and characterize
nonclassical states of motion including "Schroedinger-cat" states. A
fundamental quantum logic gate is realized which uses two states of the
quantized ion motion and two ion internal states as qubits. We explore some of
the applications for, and problems in realizing, quantum computation based on
multiple trapped ions.
| [
{
"version": "v1",
"created": "Mon, 12 May 1997 23:03:19 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Wineland",
"D. J.",
""
],
[
"Monroe",
"C.",
""
],
[
"Meekhof",
"D. M.",
""
],
[
"King",
"B. E.",
""
],
[
"Leibfried",
"D.",
""
],
[
"Itano",
"W. M.",
""
],
[
"Bergquist",
"J. C.",
""
],
[
"Berkeland",
"D.",
""
],
[
"Bollinger",
"J. J.",
""
],
[
"Miller",
"J.",
""
]
] |
quant-ph/9705023 | Samuel Joseph | Joseph Samuel and Supurna Sinha | Thomas Rotation and Polarised Light: A non-Abelian Geometric Phase in
Optics | 14 pages, Latex file, one figure, to appear in Pramana J. Phys | null | null | null | quant-ph | null | We describe a non-Abelian Berry phase in polarisation optics, suggested by an
analogy due to Nityananda between boosts in special relativity and the effect
of elliptic dichroism on polarised light. The analogy permits a simple optical
realization of the non-Abelian gauge field describing Thomas rotation. We also
show how Thomas rotation can be understood geometrically on the Poincar\'{e}
sphere in terms of the Pancharatnam phase.
| [
{
"version": "v1",
"created": "Tue, 13 May 1997 08:05:44 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Samuel",
"Joseph",
""
],
[
"Sinha",
"Supurna",
""
]
] |
quant-ph/9705024 | Yuri Shtanov | Yuri Shtanov (IUCAA, Pune, India, and Bogoliubov Institute, Kiev,
Ukraine) | Origin of quantum randomness in the pilot wave quantum mechanics | 18 pages, revtex, epsfig, 1 figure | null | null | IUCAA-38/97 | quant-ph | null | We account for the origin of the laws of quantum probabilities in the de
Broglie-Bohm (pilot wave) formulation of quantum theory by considering the
property of ergodicity likely to characterise the dynamics of microscopic
quantum systems.
| [
{
"version": "v1",
"created": "Wed, 14 May 1997 06:49:20 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Shtanov",
"Yuri",
"",
"IUCAA, Pune, India, and Bogoliubov Institute, Kiev,\n Ukraine"
]
] |
quant-ph/9705025 | Giacomo Mauro D'Ariano | G. M. D'Ariano and M. G. A. Paris (Dipartimento di Fisica 'Alessandro
Volta', Pavia, Italy) | The Quantum Tomographic Roulette Wheel | 1 ps figure. art10.sty and adacta.sty included. Submitted to Acta
Physica Slovaca | Acta Phys.Slov. 47 (1997) 1-10 | null | null | quant-ph | null | Random-phase homodyne tomography of the field intensity is a concrete example
of the Quantum Roulette of Helstrom. In this paper we give the explicit POM of
such measurement and compare it with direct photodetection and heterodyne
detection. Effects of nonunit quantum efficiency are also considered. Naimark
extensions for the roulette POM are analyzed and its experimental realization
is discussed.
| [
{
"version": "v1",
"created": "Tue, 13 May 1997 14:48:41 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"D'Ariano",
"G. M.",
"",
"Dipartimento di Fisica 'Alessandro\n Volta', Pavia, Italy"
],
[
"Paris",
"M. G. A.",
"",
"Dipartimento di Fisica 'Alessandro\n Volta', Pavia, Italy"
]
] |
quant-ph/9705026 | Vladimir Privman | Vladimir Privman, Dima Mozyrsky, Steven P. Hotaling | Hamiltonians for Quantum Computing | 13 pages in LaTeX | Proc.SPIE Int.Soc.Opt.Eng.3076:84-96,1997 | 10.1117/12.277664 | null | quant-ph | null | We argue that the analog nature of quantum computing makes the usual design
approach of constructing complicated logical operations from many simple gates
inappropriate. Instead, we propose to design multi-spin quantum gates in which
the input and output two-state systems (spins) are not necessarily identical.
We outline the design criteria for such devices and then review recent results
for single-unit Hamiltonians that accomplish the NOT and XOR functions.
| [
{
"version": "v1",
"created": "Tue, 13 May 1997 15:03:44 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Privman",
"Vladimir",
""
],
[
"Mozyrsky",
"Dima",
""
],
[
"Hotaling",
"Steven P.",
""
]
] |
quant-ph/9705027 | S. Wallentowitz | S. Wallentowitz and W. Vogel | Quantum mechanical counterpart of nonlinear optics | 6 pages, 4 figures, to be published in Phys. Rev. A 55 (June) | null | 10.1103/PhysRevA.55.4438 | null | quant-ph | null | Raman-type laser excitation of a trapped atom allows one to realize the
quantum mechanical counterpart of phenomena of nonlinear optics, such as
Kerr-type nonlinearities, parametric amplification, and multi-mode mixing.
Additionally, huge nonlinearities emerge from the interference of the atomic
wave function with the laser waves. They lead to a partitioning of the phase
space accompanied by a significantly different action of the time evolution in
neighboring phase-space zones. For example, a nonlinearly modified coherent
"displacement" of the motional quantum state may induce strong amplitude
squeezing and quantum interferences.
| [
{
"version": "v1",
"created": "Thu, 15 May 1997 13:18:22 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Wallentowitz",
"S.",
""
],
[
"Vogel",
"W.",
""
]
] |
quant-ph/9705028 | S. Wallentowitz | S. Wallentowitz, R.L. de Matos Filho, and W. Vogel | Determination of entangled quantum states of a trapped atom | 7 pages, 3 figures, to be published in Phys. Rev. A 56 (Aug) | null | 10.1103/PhysRevA.56.1205 | null | quant-ph | null | We propose a method for measuring entangled vibronic quantum states of a
trapped atom. It is based on the nonlinear dynamics of the system that appears
by resonantly driving a weak electronic transition. The proposed technique
allows the direct sampling of a Wigner-function matrix, displaying all knowable
information on the quantum correlations of the motional and electronic degrees
of freedom of the atom. It opens novel possibilities for testing fundamental
predictions of the quantum theory concerning interaction phenomena.
| [
{
"version": "v1",
"created": "Thu, 15 May 1997 15:20:09 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Wallentowitz",
"S.",
""
],
[
"Filho",
"R. L. de Matos",
""
],
[
"Vogel",
"W.",
""
]
] |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.