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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9903048 | Yoon-Ho Kim | Yoon-Ho Kim, Maria V. Chekhova, Sergei P. Kulik, Yanhua Shih, Timothy
E. Keller and Morton H. Rubin | Quantum interference by two temporally distinguishable pulses | two-column, 4pages, submitted to PRA, minor changes | Phys.Rev. A60 (1999) 37 | 10.1103/PhysRevA.60.R37 | null | quant-ph | null | We report a two-photon interference effect, in which the entangled photon
pairs are generated from two laser pulses well-separated in time. In a single
pump pulse case, interference effects did not occur in our experimental scheme.
However, by introducing a second pump pulse delayed in time, quantum
interference was then observed. The visibility of the interference fringes
shows dependence on the delay time between two laser pulses. The results are
explained in terms of indistinguishability of biphoton amplitudes which
originated from two temporally separated laser pulses.
| [
{
"version": "v1",
"created": "Sat, 13 Mar 1999 04:56:04 GMT"
},
{
"version": "v2",
"created": "Tue, 6 Apr 1999 18:30:05 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Kim",
"Yoon-Ho",
""
],
[
"Chekhova",
"Maria V.",
""
],
[
"Kulik",
"Sergei P.",
""
],
[
"Shih",
"Yanhua",
""
],
[
"Keller",
"Timothy E.",
""
],
[
"Rubin",
"Morton H.",
""
]
] |
quant-ph/9903049 | Vlatko Vedral | V. Vedral | Landauer's erasure, error correction and entanglement | 11 pages, 1 figure, to appear in The Proceedings of The Royal Society | null | 10.1098/rspa.2000.0545 | null | quant-ph | null | Classical and quantum error correction are presented in the form of Maxwell's
demon and their efficiency analyzed from the thermodynamic point of view. We
explain how Landauer's principle of information erasure applies to both cases.
By then extending this principle to entanglement manipulations we rederive
upper bounds on purification procedures thereby linking the ''no local increase
of entanglement'' principle to the Second Law of thermodynamics.
| [
{
"version": "v1",
"created": "Sun, 14 Mar 1999 15:35:07 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Dec 1999 16:04:51 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Vedral",
"V.",
""
]
] |
quant-ph/9903050 | Tamas Csorgo | T. Csorgo | Coherent states of the creation operator from fully developed
Bose-Einstein condensates | LaTeX, 9 pages, uses hip-artc.sty, no figures | Heavy Ion Phys. 9 (1999) 161 | null | null | quant-ph | null | A fully developed Bose-Einstein condensate, containing macroscopically large
number of bosons can under certain conditions be considered as a generalized
vacuum state. Applying the annihilation operator to the condensate, hole states
can be defined. Infinite ladders of such hole states can be considered as
generalized coherent states of the creation operator. Dedicated to the memory
of V. N. Gribov.
| [
{
"version": "v1",
"created": "Sun, 14 Mar 1999 22:14:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Csorgo",
"T.",
""
]
] |
quant-ph/9903051 | Ulrich Mohrhoff | Ulrich Mohrhoff (Sri Aurobindo Ashram, Pondicherry) | The Pondicherry interpretation of quantum mechanics | TeX, 38 pages, forthcoming in American Journal of Physics under the
title ``What quantum mechanics is trying to tell us'', v2: revised
submission, v3: changes in proof | Am.J.Phys. 68 (2000) 728-745 | 10.1119/1.19535 | SAAPS-990313 | quant-ph | null | This article presents a novel interpretation of quantum mechanics. It extends
the meaning of ``measurement'' to include all property-indicating facts.
Intrinsically space is undifferentiated: there are no points on which a world
of locally instantiated physical properties could be built. Instead, reality is
built on facts, in the sense that the properties of things are extrinsic, or
supervenient on property-indicating facts. The actual extent to which the world
is spatially and temporally differentiated (that is, the extent to which
spatiotemporal relations and distinctions are warranted by the facts) is
necessarily limited. Notwithstanding that the state vector does nothing but
assign probabilities, quantum mechanics affords a complete understanding of the
actual world. If there is anything that is incomplete, it is the actual world,
but its incompleteness exists only in relation to a conceptual framework that
is more detailed than the actual world. Two deep-seated misconceptions are
responsible for the interpretational difficulties associated with quantum
mechanics: the notion that the spatial and temporal aspects of the world are
adequately represented by sets with the cardinality of the real numbers, and
the notion of an instantaneous state that evolves in time. The latter is an
unwarranted (in fact, incoherent) projection of our apparent ``motion in time''
into the world of physics. Equally unwarranted, at bottom, is the use of causal
concepts. There nevertheless exists a ``classical'' domain in which language
suggestive of nomological necessity may be used. Quantum mechanics not only is
strictly consistent with the existence of this domain but also presupposes it
in several ways.
| [
{
"version": "v1",
"created": "Mon, 15 Mar 1999 03:06:42 GMT"
},
{
"version": "v2",
"created": "Thu, 26 Aug 1999 08:58:34 GMT"
},
{
"version": "v3",
"created": "Sat, 4 Mar 2000 05:09:37 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Mohrhoff",
"Ulrich",
"",
"Sri Aurobindo Ashram, Pondicherry"
]
] |
quant-ph/9903052 | Klaus Colanero | K. Colanero and M.-C. Chu | The Schrodinger particle in an oscillating spherical cavity | 9 pages, 6 figures, corrected typos | Physical Review A 60, 1845 (1999) | 10.1103/PhysRevA.60.1845 | null | quant-ph | null | We study a Schrodinger particle in an infinite spherical well with an
oscillating wall. Parametric resonances emerge when the oscillation frequency
is equal to the energy difference between two eigenstates of the static cavity.
Whereas an analytic calculation based on a two-level system approximation
reproduces the numerical results at low driving amplitudes, epsilon, we observe
a drastic change of behaviour when epsilon > 0.1, when new resonance states
appear bearing no apparent relation to the eigenstates of the static system.
| [
{
"version": "v1",
"created": "Mon, 15 Mar 1999 08:21:48 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Sep 1999 04:21:14 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Colanero",
"K.",
""
],
[
"Chu",
"M. -C.",
""
]
] |
quant-ph/9903053 | T. K. Rai Dastidar | T K Rai Dastidar (Indian Association for the Cultivation of Science,
Calcutta, India) | Father Time. I. Does the Cosmic Microwave Background Radiation Provide a
Universal Arrow of Time ? | To appear in Mod.Phys.Lett. A. This is a slightly revised version
which has been communicated to the EPS-HEP99 Conference at Tampere, Finland
(15-21 July 1999) [Abs 12_204] | Mod.Phys.Lett. A14 (1999) 2499-2505 | 10.1142/S0217732399002601 | null | quant-ph astro-ph hep-th | null | The existence of a non-thermodynamic arrow of time was demonstrated in a
recent paper (Mod.Phys.Lett. A13, 1265 (1998)), in which a model of non-local
Quantum Electrodynamics was formulated through the principle of gauge
invariance. In this paper we show that the Cosmic Microwave Background
Radiation is capable of making every particle of the universe (except those
which are not acted upon by an electromagnetic field) follow this arrow of
time.
| [
{
"version": "v1",
"created": "Mon, 15 Mar 1999 10:29:38 GMT"
},
{
"version": "v2",
"created": "Thu, 3 Jun 1999 11:46:35 GMT"
},
{
"version": "v3",
"created": "Thu, 21 Oct 1999 07:42:35 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Dastidar",
"T K Rai",
"",
"Indian Association for the Cultivation of Science,\n Calcutta, India"
]
] |
quant-ph/9903054 | Martin Plenio | Daniel Jonathan and Martin B. Plenio | Minimal conditions for local pure-state entanglement manipulation | 5 pages revtex, no figures; minor changes, revised endnote | Phys.Rev.Lett.83:1455,1999 | 10.1103/PhysRevLett.83.1455 | null | quant-ph | null | We find a minimal set of necessary and sufficient conditions for the
existence of a local procedure that converts a finite pure state into one of a
set of possible final states. This result provides a powerful method for
obtaining optimal local entanglement manipulation protocols for pure initial
states. As an example, we determine analytically the optimal distillable
entanglement for arbitrary finite pure states. We also construct an explicit
protocol achieving this bound.
| [
{
"version": "v1",
"created": "Mon, 15 Mar 1999 20:37:15 GMT"
},
{
"version": "v2",
"created": "Wed, 17 Mar 1999 19:16:49 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Jonathan",
"Daniel",
""
],
[
"Plenio",
"Martin B.",
""
]
] |
quant-ph/9903055 | Andrew T. Sornborger | A. T. Sornborger (Fermilab), E. D. Stewart (Fermilab) | Higher Order Methods for Simulations on Quantum Computers | 21 pages, Latex, one figure | Phys.Rev. A60 (1999) 1956 | 10.1103/PhysRevA.60.1956 | Fermilab Preprint: Pub-99/044-A | quant-ph | null | To efficiently implement many-qubit gates for use in quantum simulations on
quantum computers we develop and present methods reexpressing exp[-i (H_1 + H_2
+ ...) \Delta t] as a product of factors exp[-i H_1 \Delta t], exp[-i H_2
\Delta t], ... which is accurate to 3rd or 4th order in \Delta t. The methods
we derive are an extended form of symplectic method and can also be used for
the integration of classical Hamiltonians on classical computers. We derive
both integral and irrational methods, and find the most efficient methods in
both cases.
| [
{
"version": "v1",
"created": "Mon, 15 Mar 1999 23:59:38 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Sornborger",
"A. T.",
"",
"Fermilab"
],
[
"Stewart",
"E. D.",
"",
"Fermilab"
]
] |
quant-ph/9903056 | Igor Bargatin | I.V. Bargatin, B.A. Grishanin, and V.N. Zadkov | Generation of entanglement in a system of two dipole-interacting atoms
by means of laser pulses | 4 pages, 3 figures; submitted to the proceedings of the III Adriatico
Research Conference on Quantum Interferometry, ICTP, March 1-5,1999; replaced
with the final submitted version | null | 10.1002/(SICI)1521-3978(200005)48:5/7<637::AID-PROP637>3.0.CO;2-8 | null | quant-ph | null | Effectiveness of using laser field to produce entanglement between two
dipole-interacting identical two-level atoms is considered in detail. The
entanglement is achieved by driving the system with a carefully designed laser
pulse transferring the system's population to one of the maximally entangled
Dicke states in a way analogous to population inversion by a resonant
$\pi$-pulse in a two-level atom. It is shown that for the optimally chosen
pulse frequency, power and duration, the fidelity of generating a maximally
entangled state approaches unity as the distance between the atoms goes to
zero.
| [
{
"version": "v1",
"created": "Tue, 16 Mar 1999 12:46:27 GMT"
},
{
"version": "v2",
"created": "Fri, 5 Nov 1999 14:28:32 GMT"
},
{
"version": "v3",
"created": "Sat, 6 Nov 1999 12:24:49 GMT"
}
] | 2017-04-26T00:00:00 | [
[
"Bargatin",
"I. V.",
""
],
[
"Grishanin",
"B. A.",
""
],
[
"Zadkov",
"V. N.",
""
]
] |
quant-ph/9903057 | Seth Lloyd | Seth Lloyd | Quantum search without entanglement | 9 pages, TeX, submitted to Physical Review Letters | null | 10.1103/PhysRevA.61.010301 | null | quant-ph | null | Entanglement of quantum variables is usually thought to be a prerequisite for
obtaining quantum speed-ups of information processing tasks such as searching
databases. This paper presents methods for quantum search that give a speed-up
over classical methods, but that do not require entanglement. These methods
rely instead on interference to provide a speed-up. Search without entanglement
comes at a cost: although they outperform analogous classical devices, the
quantum devices that perform the search are not universal quantum computers and
require exponentially greater overhead than a quantum computer that operates
using entanglement. Quantum search without entanglement is compared to
classical search using waves.
| [
{
"version": "v1",
"created": "Tue, 16 Mar 1999 14:16:17 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Lloyd",
"Seth",
""
]
] |
quant-ph/9903058 | Xiao-Guang Wang | Xiao-Guang Wang and Hong-Chen Fu | Excited Binomial States and Excited Negative Binomial States of the
Radiation Field and Some of their Statistical Properties | 7 pages, 4 figures | Int.J.Theor.Phys.39:1437-1444,2000 | 10.1023/A:1003619724681 | null | quant-ph | null | We introduce excited binomial states and excited negative binomial states of
the radiation field by repeated application of the photon creation operator on
binomial states and negative binomial states. They reduce to Fock states and
excited coherent states in certain limits and can be viewed as intermediate
states between Fock states and coherent states. We find that both the excited
binomial states and excited negative binomial states can be exactly normalized
in terms of hypergeometric functions. Base on this interesting character, some
of the statistical properties are discussed.
| [
{
"version": "v1",
"created": "Tue, 16 Mar 1999 15:05:58 GMT"
},
{
"version": "v2",
"created": "Fri, 9 Apr 1999 07:59:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Wang",
"Xiao-Guang",
""
],
[
"Fu",
"Hong-Chen",
""
]
] |
quant-ph/9903059 | Martin Plenio | A.Beige, S.F.Huelga, P.L.Knight, M.B.Plenio, and R.C.Thompson | Coherent manipulation of two dipole-dipole interacting ions | 12 pages including 9 figures | J.Mod.Opt. 47 (2000) 401-414 | 10.1080/09500340008244051 | null | quant-ph | null | We investigate to what extent two trapped ions can be manipulated coherently
when their coupling is mediated by a dipole-dipole interaction. We will show
how the resulting level shift induced by this interaction can be used to create
entanglement, while the decay of the states remains nearly negligible. This
will allow us to implement conditional dynamics (a CNOT gate) and single qubit
operations. We propose two different experimental realisations where a large
level shift can be achieved and discuss both the strengths and weaknesses of
this scheme from the point of view of a practical realization.
| [
{
"version": "v1",
"created": "Wed, 17 Mar 1999 09:50:59 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Beige",
"A.",
""
],
[
"Huelga",
"S. F.",
""
],
[
"Knight",
"P. L.",
""
],
[
"Plenio",
"M. B.",
""
],
[
"Thompson",
"R. C.",
""
]
] |
quant-ph/9903060 | Juan Leon | J. Leon, J. Julve, P. Pitanga and F. J. de Urries | Time of arrival through a quantum barrier | 23 pages with 3 figures | Phys.Rev. D61 (2000) 062101 | null | IMAFF-PCC/99-17 | quant-ph | null | We introduce a formalism for the calculation of the time of arrival t at a
detector of particles traveling through interacting environments. We develop a
general formulation that employs quantum canonical transformations from the
free to the interacting cases to compute t. We interpret our results in terms
of a Positive Operator Valued Measure. We then compute the probability
distribution in times of arrival at a detector of those particles that, after
their initial preparation, have undergone quantum tunneling or reflection due
to the presence of potential barriers. We obtain the expected retardation or
advancement for transmitted wave packets, and non-foreseen double bump
structures for some cases of reflection.
| [
{
"version": "v1",
"created": "Wed, 17 Mar 1999 20:31:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Leon",
"J.",
""
],
[
"Julve",
"J.",
""
],
[
"Pitanga",
"P.",
""
],
[
"de Urries",
"F. J.",
""
]
] |
quant-ph/9903061 | Leah Henderson | R.Cleve, A. Ekert, L. Henderson, C. Macchiavello and M. Mosca | On Quantum Algorithms | 15 pages, 8 figures | Complexity 4 (1998) 33 | null | null | quant-ph | null | Quantum computers use the quantum interference of different computational
paths to enhance correct outcomes and suppress erroneous outcomes of
computations. In effect, they follow the same logical paradigm as
(multi-particle) interferometers. We show how most known quantum algorithms,
including quantum algorithms for factorising and counting, may be cast in this
manner. Quantum searching is described as inducing a desired relative phase
between two eigenvectors to yield constructive interference on the sought
elements and destructive interference on the remaining terms.
| [
{
"version": "v1",
"created": "Wed, 17 Mar 1999 19:34:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cleve",
"R.",
""
],
[
"Ekert",
"A.",
""
],
[
"Henderson",
"L.",
""
],
[
"Macchiavello",
"C.",
""
],
[
"Mosca",
"M.",
""
]
] |
quant-ph/9903062 | Julian Ting | Julian Juhi-Lian Ting | Stochastic resonance for quantum channels | 3 pages, 4 figures, RevTeX | Phys.Rev.E59:2801-2803,1999 | 10.1103/PhysRevE.59.2801 | null | quant-ph chao-dyn cond-mat.stat-mech nlin.CD nlin.SI solv-int | null | The concept of stochastic resonance in nonlinear dynamics is applied to
interpret the capacity of noisy quantum channels. The two-Pauli channel is used
to illustrate the idea. The fidelity of the channel is also considered. Noise
enhancement is found for the fidelity but not for the capacity.
| [
{
"version": "v1",
"created": "Wed, 17 Mar 1999 21:04:59 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Ting",
"Julian Juhi-Lian",
""
]
] |
quant-ph/9903063 | Daniel F. V. James | G.P. Berman, D.F.V. James, R.J. Hughes, M.S. Gulley, M.H. Holzscheiter
and G.V. Lopez | Dynamical Stability and Quantum Chaos of Ions in a Linear Trap | 24 pages, 17 figures, submitted to Phys. Rev A | null | 10.1103/PhysRevA.61.023403 | LAUR-99-1217 | quant-ph | null | The realization of a paradigm chaotic system, namely the harmonically driven
oscillator, in the quantum domain using cold trapped ions driven by lasers is
theoretically investigated. The simplest characteristics of regular and chaotic
dynamics are calculated. The possibilities of experimental realization are
discussed.
| [
{
"version": "v1",
"created": "Thu, 18 Mar 1999 23:43:58 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Berman",
"G. P.",
""
],
[
"James",
"D. F. V.",
""
],
[
"Hughes",
"R. J.",
""
],
[
"Gulley",
"M. S.",
""
],
[
"Holzscheiter",
"M. H.",
""
],
[
"Lopez",
"G. V.",
""
]
] |
quant-ph/9903064 | Alexandre Tort | F. C. Santos, A. Tenorio and A. C. Tort | Zeta function method and repulsive Casimir forces for an unusual pair of
plates at finite temperature | latex file 9 pages, 3 figures | Phys.Rev. D60 (1999) 105022 | 10.1103/PhysRevD.60.105022 | fit/if/ufrj 001-99 | quant-ph | null | We apply the generalized zeta function method to compute the Casimir energy
and pressure between an unusual pair of parallel plates at finite temperature,
namely: a perfectly conducting plate and an infinitely permeable one. The high
and low temperature limits of these quantities are discussed; relationships
between high and low temperature limits are estabkished by means of a modified
version of the temperature inversion symmetry.
| [
{
"version": "v1",
"created": "Wed, 17 Mar 1999 22:27:56 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Santos",
"F. C.",
""
],
[
"Tenorio",
"A.",
""
],
[
"Tort",
"A. C.",
""
]
] |
quant-ph/9903065 | Tom Montroy | Mark S. Sherwin, Atac Imamoglu, Thomas Montroy (University of
California, Santa Barbara) | Quantum Computation with Quantum Dots and Terahertz Cavity Quantum
Electrodynamics | Revtex 6 pages, 3 postscript figures, minor typos corrected | null | 10.1103/PhysRevA.60.3508 | null | quant-ph | null | A quantum computer is proposed in which information is stored in the two
lowest electronic states of doped quantum dots (QDs). Many QDs are located in a
microcavity. A pair of gates controls the energy levels in each QD. A
Controlled Not (CNOT) operation involving any pair of QDs can be effected by a
sequence of gate-voltage pulses which tune the QD energy levels into resonance
with frequencies of the cavity or a laser. The duration of a CNOT operation is
estimated to be much shorter than the time for an electron to decohere by
emitting an acoustic phonon.
| [
{
"version": "v1",
"created": "Thu, 18 Mar 1999 00:32:40 GMT"
},
{
"version": "v2",
"created": "Thu, 18 Mar 1999 22:56:49 GMT"
}
] | 2019-08-17T00:00:00 | [
[
"Sherwin",
"Mark S.",
"",
"University of\n California, Santa Barbara"
],
[
"Imamoglu",
"Atac",
"",
"University of\n California, Santa Barbara"
],
[
"Montroy",
"Thomas",
"",
"University of\n California, Santa Barbara"
]
] |
quant-ph/9903066 | Caroline H. Thompson | Caroline H. Thompson (Department of Computer Science, University of
Wales Aberystwyth) | Subtraction of ``accidentals'' and the validity of Bell tests | Section on Clauser and Horne's 1974 Bell test derivations corrected
and extended. One ref added, and other minor improvements. Submitted to Phys
Rev A. See also quant-ph/9611037, quant-ph/9711044 and other documents at
<http://www.aber.ac.uk/~cat>. Material expands that of 9711044 and includes
derivation of Clauser and Horne's experimentally useful 1974 Bell test | null | null | null | quant-ph | null | In some key Bell experiments, including two of the well-known ones by Alain
Aspect, 1981-2, it is only after the subtraction of ``accidentals'' from the
coincidence counts that we get violations of Bell tests. The data adjustment,
producing increases of up to 60% in the test statistics, has never been
adequately justified. Few published experiments give sufficient information for
the reader to make a fair assessment. There is a straightforward and well known
realist model that fits the unadjusted data very well. In this paper, the logic
of this realist model and the reasoning used by experimenters in justification
of the data adjustment are discussed. It is concluded that the evidence from
all Bell experiments is in urgent need of re-assessment, in the light of all
the known ``loopholes''. Invalid Bell tests have frequently been used,
neglecting improved ones derived by Clauser and Horne in 1974. ``Local causal''
explanations for the observations have been wrongfully neglected.
| [
{
"version": "v1",
"created": "Thu, 18 Mar 1999 16:59:31 GMT"
},
{
"version": "v2",
"created": "Wed, 21 Apr 1999 17:43:15 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Thompson",
"Caroline H.",
"",
"Department of Computer Science, University of\n Wales Aberystwyth"
]
] |
quant-ph/9903067 | Stefan Weigert | Jean-Pierre Amiet and Stefan Weigert | Reconstructing the density matrix of a spin s through Stern-Gerlach
measurements (II) | Latex, 8 pages | J. Phys. A 32 (1999) L269 | 10.1088/0305-4470/32/25/101 | null | quant-ph | null | The density matrix of a spin s is fixed uniquely if the probabilities to
obtain the value s upon measuring n.S are known for 4s(s+1) appropriately
chosen directions n in space. These numbers are just the expectation values of
the density operator in coherent spin states, and they can be determined in an
experiment carried out with a Stern-Gerlach apparatus. Furthermore, the
experimental data can be inverted providing thus a parametrization of the
statistical operator by 4s(s+1) positive parameters.
| [
{
"version": "v1",
"created": "Fri, 19 Mar 1999 17:47:14 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Amiet",
"Jean-Pierre",
""
],
[
"Weigert",
"Stefan",
""
]
] |
quant-ph/9903068 | Santosh Shelly Sharma | S. Shelly Sharma(UEL,Brazil), N. K. Sharma(UEL, Brazil), and Larry
Zamick(Rutgers University) | Reply on `comment on our paper `Single two-level ion in an
anharmonic-oscillator trap: Time evolution of the Q function and population
inversion '' | Revtex, 4pages. To be Published in Physical Review A59, NO.4(April
99) | Phys.Rev.A59:3138-3140,1999 | 10.1103/PhysRevA.59.3138 | null | quant-ph nucl-th | null | We show here that the model Hamiltonian used in our paper for ion vibrating
in a q-analog harmonic oscillator trap and interacting with a classical
single-mode light field is indeed obtained by replacing the usual bosonic
creation and annihilation operators of the harmonic trap model by their
q-deformed counterparts. The approximations made in our paper amount to using
for the ion-laser interaction in a q-analog harmonic oscillator trap, the
operator $F_{q}=exp{-(|\epsilon|^2}/2)}exp{i\epsilon A^{\dagger}}exp{i\epsilon
A}$, which is analogous to the corresponding operator for ion in a harmonic
oscillator trap that is $F=exp{-(|\epsilon|^2 /2)}exp{i\epsilon a^{\dagger
}}exp{i\epsilon a}$. In our article we do not claim to have diagonalized the
operator, $F_q = exp{i \epsilon (A^{\dagger}+A)}$, for which the basis states
|g,m> and |e,m> are not analytic vectors.
| [
{
"version": "v1",
"created": "Fri, 19 Mar 1999 21:20:44 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Sharma",
"S. Shelly",
"",
"UEL,Brazil"
],
[
"Sharma",
"N. K.",
"",
"UEL, Brazil"
],
[
"Zamick",
"Larry",
"",
"Rutgers University"
]
] |
quant-ph/9903069 | Oscar Wallace Greenberg | O.W. Greenberg | Small Violations of Statistics | 22 pages, latex, no figures | null | null | University of Maryland Physics Paper 99-101 | quant-ph hep-ph hep-th nucl-th | null | There are two motivations to consider statistics that are neither Bose nor
Fermi: (1) to extend the framework of quantum theory and of quantum field
theory, and (2) to provide a quantitative measure of possible violations of
statistics. After reviewing tests of statistics for various particles, and
types of statistics that are neither Bose nor Fermi, I discuss quons, particles
characterized by the parameter $q$, which permit a smooth interpolation between
Bose and Fermi statistics; $q=1$ gives bosons, $q=-1$ gives fermions. The new
result of this talk is work by Robert C. Hilborn and myself that gives a
heuristic argument for an extension of conservation of statistics to quons with
trilinear couplings of the form $\bar{f}fb$, where $f$ is fermion-like and $b$
is boson-like. We showed that $q_f^2=q_b$. In particular, we related the bound
on $q_{\gamma}$ for photons to the bound on $q_e$ for electrons, allowing the
very precise bound for electrons to be carried over to photons. An extension of
our argument suggests that all particles are fermions or bosons to high
precision.
| [
{
"version": "v1",
"created": "Fri, 19 Mar 1999 22:10:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Greenberg",
"O. W.",
""
]
] |
quant-ph/9903070 | Benjamin Pablo-Norman | B. Pablo-Norman and M. Ruiz-Altaba | Noise in Grover's Quantum Search Algorithm | 17 pages, 2 eps figures. Revised version. To be published in PRA,
December 1999 | AIP Conf.Proc. 490 (1999) 405-408 | 10.1103/PhysRevA.61.012301 | PREPRINT IFUNAM-FT-99-01 | quant-ph | null | Grover's quantum algorithm improves any classical search algorithm. We show
how random Gaussian noise at each step of the algorithm can be modelled easily
because of the exact recursion formulas available for computing the quantum
amplitude in Grover's algorithm. We study the algorithm's intrinsic robustness
when no quantum correction codes are used, and evaluate how much noise the
algorithm can bear with, in terms of the size of the phone book and a desired
probability of finding the correct result. The algorithm loses efficiency when
noise is added, but does not slow down. We also study the maximal noise under
which the iterated quantum algorithm is just as slow as the classical
algorithm. In all cases, the width of the allowed noise scales with the size of
the phone book as N^-2/3.
| [
{
"version": "v1",
"created": "Sat, 20 Mar 1999 01:46:16 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Apr 1999 19:10:15 GMT"
},
{
"version": "v3",
"created": "Tue, 9 Nov 1999 02:30:50 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Pablo-Norman",
"B.",
""
],
[
"Ruiz-Altaba",
"M.",
""
]
] |
quant-ph/9903071 | Michele Mosca | Michele Mosca and Artur Ekert (Centre for Quantum Computation, Oxford) | The Hidden Subgroup Problem and Eigenvalue Estimation on a Quantum
Computer | 16 pages, 3 figures, LaTeX2e, to appear in Proceedings of the 1st
NASA International Conference on Quantum Computing and Quantum Communication
(Springer-Verlag) | null | null | null | quant-ph | null | A quantum computer can efficiently find the order of an element in a group,
factors of composite integers, discrete logarithms, stabilisers in Abelian
groups, and `hidden' or `unknown' subgroups of Abelian groups. It is already
known how to phrase the first four problems as the estimation of eigenvalues of
certain unitary operators. Here we show how the solution to the more general
Abelian `hidden subgroup problem' can also be described and analysed as such.
We then point out how certain instances of these problems can be solved with
only one control qubit, or `flying qubits', instead of entire registers of
control qubits.
| [
{
"version": "v1",
"created": "Sat, 20 Mar 1999 13:55:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mosca",
"Michele",
"",
"Centre for Quantum Computation, Oxford"
],
[
"Ekert",
"Artur",
"",
"Centre for Quantum Computation, Oxford"
]
] |
quant-ph/9903072 | Leo Stodolsky | L. Stodolsky | Decoherence - Fluctuation Relation and Measurement Noise | 6 pages, no figures, for Okun Festschrift, Physics Reports | Phys.Rept.320:51,1999 | 10.1016/S0370-1573(99)00065-4 | MPI-PTh/99-11 | quant-ph | null | We discuss fluctuations in the measurement process and how these fluctuations
are related to the dissipational parameter characterising quantum damping or
decoherence. On the example of the measuring current of the variable-barrier or
QPC problem we show there is an extra noise or fluctuation connected with the
possible different outcomes of a measurement. This noise has an enhanced short
time component which could be interpreted as due to ``telegraph noise'' or
``wavefunction collapses''. Furthermore the parameter giving the the strength
of this noise is related to the parameter giving the rate of damping or
decoherence.
| [
{
"version": "v1",
"created": "Mon, 22 Mar 1999 15:35:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Stodolsky",
"L.",
""
]
] |
quant-ph/9903073 | Rozmej | P. Rozmej (University MCS, Lublin, Poland) and R. Arvieu (ISN,
Grenoble, France) | The Dirac Oscillator. A relativistic version of the Jaynes--Cummings
model | LaTeX2e, uses IOP style files (included), 14 pages, 9 separate
postscript figures | J.Phys.A32:5367-5382,1999 | 10.1088/0305-4470/32/28/314 | null | quant-ph math-ph math.MP physics.atom-ph | null | The dynamics of wave packets in a relativistic Dirac oscillator is compared
to that of the Jaynes-Cummings model. The strong spin-orbit coupling of the
Dirac oscillator produces the entanglement of the spin with the orbital motion
similar to what is observed in the model of quantum optics. The collapses and
revivals of the spin which result extend to a relativistic theory our previous
findings on nonrelativistic oscillator where they were known under the name of
`spin-orbit pendulum'. There are important relativistic effects (lack of
periodicity, zitterbewegung, negative energy states). Many of them disappear
after a Foldy-Wouthuysen transformation.
| [
{
"version": "v1",
"created": "Mon, 22 Mar 1999 13:30:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Rozmej",
"P.",
"",
"University MCS, Lublin, Poland"
],
[
"Arvieu",
"R.",
"",
"ISN,\n Grenoble, France"
]
] |
quant-ph/9903074 | Pieter Kok | Pieter Kok, Samuel L. Braunstein | Postselected versus nonpostselected quantum teleportation using
parametric down-conversion | 11 pages, 4 figures (REVTeX) Phys Rev A, 61, 42304 (2000) | Phys.Rev.A61:42304,2000 | 10.1103/PhysRevA.61.042304 | null | quant-ph | null | We study the experimental realisation of quantum teleportation as performed
by Bouwmeester {\em et al}. [Nature {\bf 390}, 575 (1997)] and the adjustments
to it suggested by Braunstein and Kimble [Nature {\bf 394}, 841 (1998)]. These
suggestions include the employment of a detector cascade and a relative
slow-down of one of the two down-converters. We show that coincidences between
photon-pairs from parametric down-conversion automatically probe the
non-Poissonian structure of these sources. Furthermore, we find that detector
cascading is of limited use, and that modifying the relative strengths of the
down-conversion efficiencies will increase the time of the experiment to the
order of weeks. Our analysis therefore points to the benefits of single-photon
detectors in non-post-selected type experiments, a technology currently
requiring roughly $6^{\circ}$K operating conditions.
| [
{
"version": "v1",
"created": "Mon, 22 Mar 1999 15:21:17 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Mar 2000 12:08:16 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Kok",
"Pieter",
""
],
[
"Braunstein",
"Samuel L.",
""
]
] |
quant-ph/9903075 | Sixia Yu | Sixia Yu and Chang-Pu Sun | Quantum searching's underlying SU(2) structure and its quantum
decoherence effects | 11 Pages; RevTex | null | null | null | quant-ph | null | The search operation for a marked state by means of Grover's quantum
searching algorithm is shown to be an element of group SU(2) which acts on a
2-dimensional space spanned by the marked state and the unmarked collective
state. Based on this underlying structure, those exact bounds of the steps in
various quantum search algorithms are obtained in a quite concise way. This
reformulation of the quantum searching algorithm also enables a detailed
analysis of the decoherence effects caused by its coupling with an environment.
It turns out that the environment will not only make the quantum search invalid
in case of complete decoherence, where the probability of finding the marked
state is unchanged, but also it may make the quantum search algorithm worse
than expected: It will decrease this probability when the environment shows its
quantum feature.
| [
{
"version": "v1",
"created": "Tue, 23 Mar 1999 07:05:08 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Yu",
"Sixia",
""
],
[
"Sun",
"Chang-Pu",
""
]
] |
quant-ph/9903076 | Avi Marhavka | A. Marchewka and Z. Schuss | A Path Intergal Approach to Current | 17 pages, Latex | Phys.Rev.A61:052107,2000 | 10.1103/PhysRevA.61.052107 | TAUP-2570-99 | quant-ph | null | Discontinuous initial wave functions or wave functions with discontintuous
derivative and with bounded support arise in a natural way in various
situations in physics, in particular in measurement theory. The propagation of
such initial wave functions is not well described by the Schr\"odinger current
which vanishes on the boundary of the support of the wave function. This
propagation gives rise to a uni-directional current at the boundary of the
support. We use path integrals to define current and uni-directional current
and give a direct derivation of the expression for current from the path
integral formulation for both diffusion and quantum mechanics. Furthermore, we
give an explicit asymptotic expression for the short time propagation of
initial wave function with compact support for both the cases of discontinuous
derivative and discontinuous wave function. We show that in the former case the
probability propagated across the boundary of the support in time $\Delta t$ is
$O(\Delta t^{3/2})$ and the initial uni-directional current is $O(\Delta
t^{1/2})$. This recovers the Zeno effect for continuous detection of a particle
in a given domain. For the latter case the probability propagated across the
boundary of the support in time $\Delta t$ is $O(\Delta t^{1/2})$ and the
initial uni-directional current is $O(\Delta t^{-1/2})$. This is an anti-Zeno
effect. However, the probability propagated across a point located at a finite
distance from the boundary of the support is $O(\Delta t)$. This gives a decay
law.
| [
{
"version": "v1",
"created": "Tue, 23 Mar 1999 11:43:53 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Marchewka",
"A.",
""
],
[
"Schuss",
"Z.",
""
]
] |
quant-ph/9903077 | Volodymyr Krasnoholovets | Volodymyr Krasnoholovets | Motion of a Relativistic Particle and the Vacuum | 19 pages, LaTeX 2e, 2 figures (PostScript files) | Physics Essays, vol. 10, no. 3, pp. 407-416 (1997) | null | null | quant-ph math-ph math.MP | null | A vacuum medium model is advanced. The motion of a relativistic particle in
relation to its interaction with the medium is discussed. It is predicted that
elementary excitations of the vacuum, called "inertons," should exist. The
equations of the particle path in Euclidean space are derived. The motion is
marked by the relations basic for quantum mechanics: $E=h\nu$ and $Mv = h/
\lambda$ (here, $\lambda$ is the amplitude of spatial oscillations of the
particle along the trajectory, i.e., the interval at which the velocity of the
particle is periodically altered from $v$ to 0 and then from 0 to $v$; $\nu$ is
the frequency of these oscillations). Analysis is performed on the transition
to wave mechanics where $\lambda$ manifests itself as the de Broglie wavelength
and $\nu$ is the distinctive frequency of the "particle-wave". A prerequisite
for the wave solution to be Lorentz-invariant is treated. A hypothesis for a
plausible hydrodynamic description of the relativistic particle motion is
covered.
| [
{
"version": "v1",
"created": "Tue, 23 Mar 1999 13:51:29 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Oct 1999 11:37:05 GMT"
},
{
"version": "v3",
"created": "Fri, 5 Nov 1999 09:10:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Krasnoholovets",
"Volodymyr",
""
]
] |
quant-ph/9903078 | Jules Beckers | J. Beckers, N. Debergh, F.H. Szafraniec | On oscillatorlike developments and further improvements in squeezing | : LaTeX, 14 pages | null | 10.1103/PhysRevA.65.042112 | null | quant-ph | null | A recent proposal of new sets of squeezed states is seen as a particular case
of a general context admitting realistic physical Hamiltonians. Such
improvements reveal themselves helpful in the study of associated squeezing
effects. Coherence is also considered.
| [
{
"version": "v1",
"created": "Tue, 23 Mar 1999 14:20:21 GMT"
}
] | 2013-05-29T00:00:00 | [
[
"Beckers",
"J.",
""
],
[
"Debergh",
"N.",
""
],
[
"Szafraniec",
"F. H.",
""
]
] |
quant-ph/9903079 | Roberto Laura | Roberto Laura, Rodolfo M. Id Betan | Subdynamics theory in the functional approach to quantum mechanics | 11 pages | Int.J.Theor.Phys. 38 (1999) 165-181 | null | null | quant-ph | null | The formalism of subdynamics is extended to the functional approach of
quantum systems, and used for the Friedrichs model, in which diagonal
singularities in states and observables are included. We compute in this
approach the generalized eigenvectors and eigenvalues of the Liouvulle-Von
Newmann operator, using an iterative scheme. As complex generalized eigenvalues
are obtained, the decay rates of unstable modes are included in the spectral
decomposition.
| [
{
"version": "v1",
"created": "Tue, 23 Mar 1999 15:24:07 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Laura",
"Roberto",
""
],
[
"Betan",
"Rodolfo M. Id",
""
]
] |
quant-ph/9903080 | Roberto Laura | R. Laura | Scattering and intrinsic irreversibility | 14 pages | International Journal of Theoretical Physycs. Vol 36 N. 11,
2315-2334 (1997) | null | null | quant-ph | null | The formalism of quantum systems with diagonal singularities is applied to
describe scattering processes. Well defined states are obtained for infinite
time, which are related to a ''weak form'' of intrinsic irreversibility. Real
and complex generalized spectral decompositions of the Liouville-Von Neumann
superoperator are computed. The physical meaning of ''Gamov states'' is
discussed.
| [
{
"version": "v1",
"created": "Wed, 24 Mar 1999 12:39:13 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Laura",
"R.",
""
]
] |
quant-ph/9903081 | Robert Carroll | Robert Carroll (UIUC) | Some remarks on time, uncertainty, and spin | Latex, 9 pages | null | 10.1139/cjp-77-4-319 | null | quant-ph hep-th | null | Some observations are made about energy-time uncertainty and spin in the
context of trajectories as in Faraggi-Matone or Floyd.
| [
{
"version": "v1",
"created": "Wed, 24 Mar 1999 21:20:03 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Carroll",
"Robert",
"",
"UIUC"
]
] |
quant-ph/9903082 | Howard M. Wiseman | H.M. Wiseman | The ultimate quantum limit to the linewidth of lasers | 10 pages of text plus one figure | null | null | null | quant-ph | null | The standard quantum limit to the linewidth of a laser for which the gain
medium can be adiabatically eliminated is $\ell_{0}=\kappa/2\bar{n}$. Here
$\kappa$ is the intensity damping rate and $\bar{n}$ the mean photon number.
This contains equal contributions from the loss and gain processes, so that
simple arguments which attribute the linewidth wholly to phase noise from
spontaneous gain are wrong. I show that an {\em unstimulated} gain process
actually introduces no phase noise, so that the ultimate quantum limit to the
laser linewidth comes from the loss alone and is equal to $\ell_{ult}=
\kappa/4\bar{n}$. I investigate a number of physical gain mechanisms which
attempt to achieve gain without phase noise: a linear atom-field coupling with
finite interaction time; a nonlinear atom-field coupling; and adiabatic photon
transfer using a counterintuitive pulse sequence. The first at best reaches the
standard limit $\ell_{0}$, the second reaches $3/4 \ell_{0}$, while the third
reaches the ultimate limit of $\ell_{ult} = 1/2 \ell_{0}$.
| [
{
"version": "v1",
"created": "Thu, 25 Mar 1999 04:43:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Wiseman",
"H. M.",
""
]
] |
quant-ph/9903083 | A. K. Rajagopal | A. K. Rajagopal | Quantum Entanglement and the Maximum Entropy States from the Jaynes
Principle | 5 pages | Phys.Rev.A60:4338,1999 | 10.1103/PhysRevA.60.4338 | null | quant-ph cond-mat.stat-mech | null | We show that the Jaynes principle is indeed a proper inference scheme when
applied to compound systems and will correctly produce the entangled maximum
entropy states compatible with appropriate data. This is accomplished by
including the dispersion of the entanglement along with its mean value as
constraints and an application of the uncertainty principle. We also construct
a "thermodynamic-like" description of the entanglement arising out of the
maximum entropy principle.
| [
{
"version": "v1",
"created": "Fri, 26 Mar 1999 14:14:19 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Rajagopal",
"A. K.",
""
]
] |
quant-ph/9903084 | Wen-Fa Lu | Wen-Fa Lu (Shanghai Jiao Tong University) | A General Type of a Coherent States with Thermal Effects | Revtex, 5 pages, no figure | null | null | SJTU-DAP-LU-9901 | quant-ph | null | Within the framework of thermofield dynamics, we construct a thermalized
coherent thermal state, which is a general type of the coherent state with the
thermal effects and can be presumably produced experimentally. The wavefunction
and the density matrix element in the coordinate repersentation are calculated,
and furthermore we give the probability densities, average values and variances
of the position, momentum and particle number, which in special cases are
consistent with those in the literature. All calculations are performed in the
coordinate representation.
| [
{
"version": "v1",
"created": "Fri, 26 Mar 1999 17:09:45 GMT"
},
{
"version": "v2",
"created": "Sat, 20 Nov 1999 15:18:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lu",
"Wen-Fa",
"",
"Shanghai Jiao Tong University"
]
] |
quant-ph/9903085 | A. K. Rajagopal | A. K. Rajagopal, K. L Jensen, and F. W. Cummings | Quantum Entangled Supercorrelated States in the Jaynes-Cummings Model | 12 pages, 3 figures | Phys.Lett. A259 (1999) 285-290 | 10.1016/S0375-9601(99)00404-1 | null | quant-ph cond-mat.stat-mech | null | The regions of independent quantum states, maximally classically correlated
states, and purely quantum entangled (supercorrelated) states described in a
recent formulation of quantum information theory by Cerf and Adami are explored
here numerically in the parameter space of the well-known exactly soluable
Jaynes-Cummings model for equilibrium and nonequilibrium time-dependent
ensembles.
| [
{
"version": "v1",
"created": "Fri, 26 Mar 1999 18:47:32 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Rajagopal",
"A. K.",
""
],
[
"Jensen",
"K. L",
""
],
[
"Cummings",
"F. W.",
""
]
] |
quant-ph/9903086 | Iver H. Brevik | J. S. H{\o}ye and I. Brevik | The Casimir Problem of Spherical Dielectrics: A Solution in Terms of
Quantum Statistical Mechanics | 12 pages, LaTeX, no figures; a note on the recent literature added at
the end. Written for a festschrift issue of Journal of Statistical Physics,
dedicated to George Stell | null | null | null | quant-ph cond-mat hep-th | null | The Casimir energy for a compact dielectric sphere is considered in a novel
way, using the quantum statistical method introduced by H\oye - Stell and
others. Dilute media are assumed. It turns out that this method is a very
powerful one: we are actually able to derive an expression for the Casimir
energy that contains also the negative part resulting from the attractive van
der Waals forces between the molecules. It is precisely this part of the
Casimir energy that has turned out to be so difficult to extract from the
formalism when using the conventional field theoretical methods for a
continuous medium. Assuming a frequency cutoff, our results are in agreement
with those recently obtained by Barton [J. Phys. A: Math. Gen. 32(1999)525].
| [
{
"version": "v1",
"created": "Sat, 27 Mar 1999 13:10:07 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Apr 1999 13:25:05 GMT"
},
{
"version": "v3",
"created": "Wed, 14 Apr 1999 14:38:43 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Høye",
"J. S.",
""
],
[
"Brevik",
"I.",
""
]
] |
quant-ph/9903087 | Tony Bracken | A. J. Bracken, G. F. Melloy | Localizing the Relativistic Electron | 19 pages including 1 figure (1 LatTex2e file, 1 postscript file).
Uses package amssymb. Typos corrected | J.Phys.A32:6127-6139,1999 | 10.1088/0305-4470/32/34/302 | DIAS-STP-98-13 | quant-ph | null | A causally well-behaved solution of the localization problem for the free
electron is given, with natural space-time transformation properties, in terms
of Dirac's position operator. It is shown that, although this operator does not
represent an observable in the usual sense, and has no positive-energy
(generalized) eigenstates, the associated 4-vector density is observable, and
can be localized arbitrarily precisely about any point in space, at any instant
of time, using only positive-energy states. A suitable spin operator can be
diagonalized at the same time.
| [
{
"version": "v1",
"created": "Sun, 28 Mar 1999 06:47:38 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bracken",
"A. J.",
""
],
[
"Melloy",
"G. F.",
""
]
] |
quant-ph/9903088 | Diosi Lajos | Lajos Diosi | On hybrid dynamics of the Copenhagen dichotomic world | 8pp LateX (ws-p8-50x6-00.cls macro), to appear in New Insights in
Quantum Mechanics (World Scientific) | null | null | null | quant-ph | null | In the Copenhagen viewpoint, part of the world is quantized and the
complementary part remains classical. From a formal dynamic aspect, standard
theory is incomplete since it does never account for the so-called
'back-reaction' of quantized systems on classical systems except for the highly
idealized system-detector interaction. To resolve this formal issue, a certain
'hybrid dynamics' can be constructed to account for the generic interaction
between classical and quantized parts. Hybrid dynamics incorporates standard
quantum theory, including collapse of the wave function during system-detector
interaction. Measurable predictions are robust against shifting the
classical-quantum boundary (von Neumann-cut).
| [
{
"version": "v1",
"created": "Sun, 28 Mar 1999 15:30:40 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Diosi",
"Lajos",
""
]
] |
quant-ph/9903089 | Timo Felbinger | Timo Felbinger and Martin Wilkens | Stochastic Wave-function Simulation of Two-time Correlation Functions | 17 pages, 3 EPS figures | null | 10.1080/09500349908231343 | null | quant-ph | null | We propose an optimized algorithm for the numerical simulation of two-time
correlation functions by means of stochastic wave functions. As a first
application, we investigate the two-time correlation function of a nonlinear
optical parametric oscillator.
| [
{
"version": "v1",
"created": "Mon, 29 Mar 1999 15:31:22 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Felbinger",
"Timo",
""
],
[
"Wilkens",
"Martin",
""
]
] |
quant-ph/9903090 | Roberto Laura | Roberto Laura and Adolfo R. Ordoniez | Internal Time Superoperator for Quantum Systems with Diagonal
Singularity | 11 pages | Int. Jour. Theor. Phys., Vol. 36, No. 11, 1997 | null | null | quant-ph | null | We generalize the concepts of Internal Time Superoperator, its associated non
unitary similarity transformations and Liapounov variables, to quantum systems
with diagonal singularity, and we give a constructive proof of the existence of
these superoperators for systems with purely diagonal Hamiltonian having
uniform absolutely continuous spectrum on the interval from zero to infinity.
| [
{
"version": "v1",
"created": "Mon, 29 Mar 1999 18:18:49 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Laura",
"Roberto",
""
],
[
"Ordoniez",
"Adolfo R.",
""
]
] |
quant-ph/9903091 | Lorenza Viola | Kristi Pance, Lorenza Viola, and S. Sridhar | Tunneling Proximity Resonances: Interplay between Symmetry and
Dissipation | Five pages, plain RevTeX; five encapsulated PostScript figures.
Submitted to Physical review Letters | Phys.Lett. A268 (2000) 399-405 | 10.1016/S0375-9601(00)00121-3 | null | quant-ph physics.optics | null | We report the first observation of bound-state proximity resonances in
coupled dielectric resonators. The proximity resonances arise from the combined
action of symmetry and dissipation. We argue that the large ratio between the
widths is a distinctive signature of the multidimensional nature of the system.
Our experiments shed light on the properties of 2D tunneling in the presence of
a dissipative environment.
| [
{
"version": "v1",
"created": "Mon, 29 Mar 1999 23:25:00 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Pance",
"Kristi",
""
],
[
"Viola",
"Lorenza",
""
],
[
"Sridhar",
"S.",
""
]
] |
quant-ph/9903092 | Galina V. Shpatakovskaya | D.A.Kirzhnits and G.V.Shpatakovskaya (Institute for Mathematical
Modelling, Russia) | Anomalies in nonrelativistic quantum mechanics | 5 pages | Theor.Math.Phys. 109 (1996) 1342-1344; Teor.Mat.Fiz. 109N1 (1996)
124-127 | null | null | quant-ph | null | It is shown that if a potential in a nonrelativistic system of Fermi
particles has a sufficiently strong singularity, anomalies (nonzero values of
quantities formally equal to zero) will probably appear. For different types of
singularities (in paticular, for the Coulomb potential), anomalies associated
with the energy and total number of particles in the system are calculated.
These anomalies may be beneficial in deriving a semiclassical description of
electron- nuclear systems.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 04:08:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kirzhnits",
"D. A.",
"",
"Institute for Mathematical\n Modelling, Russia"
],
[
"Shpatakovskaya",
"G. V.",
"",
"Institute for Mathematical\n Modelling, Russia"
]
] |
quant-ph/9903093 | Richard Shurtleff | Richard Shurtleff | Rotation Eigenvectors and Spin 1/2 | 10 pages, 3 figures, Latex2e | null | null | null | quant-ph | null | It is an easily deduced fact that any four-component spin 1/2 state for a
massive particle is a linear combination of pairs of two-component simultaneous
rotation eigenstates, where `simultaneous' means the eigenspinors of a given
pair share the same eigenvalue. The new work here constructs the reverse: Given
pairs of simultaneous rotation eigenvectors, the properties of these pairs
contains relationships that are equivalent to spin 1/2 single particle
equations. Thus the needed aspects of space-time symmetry can be produced as
special cases of more general properties already present in the rotation group.
The exercise exploits the flexibility of the rotation group in three dimensions
to deduce relativistic quantities in four dimensions.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 04:13:48 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Shurtleff",
"Richard",
""
]
] |
quant-ph/9903094 | A. Heidmann | P.F. Cohadon, A. Heidmann, M. Pinard | Cooling of a mirror by radiation pressure | 4 pages, 6 figures, RevTeX | Phys.Rev.Lett. 83 (1999) 3174-3177 | 10.1103/PhysRevLett.83.3174 | null | quant-ph | null | We describe an experiment in which a mirror is cooled by the radiation
pressure of light. A high-finesse optical cavity with a mirror coated on a
mechanical resonator is used as an optomechanical sensor of the Brownian motion
of the mirror. A feedback mechanism controls this motion via the radiation
pressure of a laser beam reflected on the mirror. We have observed either a
cooling or a heating of the mirror, depending on the gain of the feedback loop.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 09:35:03 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Oct 1999 14:39:26 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cohadon",
"P. F.",
""
],
[
"Heidmann",
"A.",
""
],
[
"Pinard",
"M.",
""
]
] |
quant-ph/9903095 | Lev Vaidman | L. Vaidman | The Meaning of Elements of Reality and Quantum Counterfactuals -- Reply
to Kastner | 10 pages | Found.Phys. 29 (1999) 865-876 | null | null | quant-ph | null | This paper is the answer to the paper by Kastner [Found. Phys., to be
published, quant-ph/9807037] in which she continued the criticism of the
counterfactual usage of the Aharonov-Bergman-Lebowitz rule in the framework of
the time-symmetrized quantum theory, in particular, by analyzing the three-box
``paradox''. It is argued that the criticism is not sound. Paradoxical features
of the three-box example has been explained. It is explained that the elements
of reality in the framework of time-symmetrized quantum theory are
counterfactual statements and, therefore, even conflicting elements of reality
can be associated with a single particle. It is shown how such
``counterfactual'' elements of reality can be useful in the analysis of a
physical experiment (the three-box example). The validity of Kastner's
application of the consistent histories approach to the time-symmetrized
counterfactuals is questioned.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 12:25:08 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Vaidman",
"L.",
""
]
] |
quant-ph/9903096 | Nikolay Vitanov | N. V. Vitanov and S. Stenholm | Adiabatic population transfer via multiple intermediate states | 14 pages, two-column revtex style, 10 figures | null | 10.1103/PhysRevA.60.3820 | null | quant-ph | null | This paper discusses a generalization of stimulated Raman adiabatic passage
(STIRAP) in which the single intermediate state is replaced by $N$ intermediate
states. Each of these states is connected to the initial state $\state{i}$ with
a coupling proportional to the pump pulse and to the final state $\state{f}$
with a coupling proportional to the Stokes pulse, thus forming a parallel
multi-$\Lambda$ system. It is shown that the dark (trapped) state exists only
when the ratio between each pump coupling and the respective Stokes coupling is
the same for all intermediate states. We derive the conditions for existence of
a more general adiabatic-transfer state which includes transient contributions
from the intermediate states but still transfers the population from state
$\state{i}$ to state $\state{f}$ in the adiabatic limit. We present various
numerical examples for success and failure of multi-$\Lambda$ STIRAP which
illustrate the analytic predictions. Our results suggest that in the general
case of arbitrary couplings, it is most appropriate to tune the pump and Stokes
lasers either just below or just above all intermediate states.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 14:31:31 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Vitanov",
"N. V.",
""
],
[
"Stenholm",
"S.",
""
]
] |
quant-ph/9903097 | Stefan Giller | Stefan Giller (Theoretical Physics Department II, University of Lodz,
Poland) | Topological Expansion and Exponential Asymptotics in 1D Quantum
Mechanics | 46 pages, 22 EPS figures | J.Phys.A33:1543-1580,2000 | 10.1088/0305-4470/33/8/304 | null | quant-ph | null | Borel summable semiclassical expansions in 1D quantum mechanics are
considered. These are the Borel summable expansions of fundamental solutions
and of quantities constructed with their help. An expansion, called
topological,is constructed for the corresponding Borel functions. Its main
property is to order the singularity structure of the Borel plane in a
hierarchical way by an increasing complexity of this structure starting from
the analytic one. This allows us to study the Borel plane singularity structure
in a systematic way. Examples of such structures are considered for linear,
harmonic and anharmonic potentials. Together with the best approximation
provided by the semiclassical series the exponentially small contribution
completing the approximation are considered. A natural method of constructing
such an exponential asymptotics relied on the Borel plane singularity
structures provided by the topological expansion is developed. The method is
used to form the semiclassical series including exponential contributions for
the energy levels of the anharmonic oscillator.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 15:11:17 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Giller",
"Stefan",
"",
"Theoretical Physics Department II, University of Lodz,\n Poland"
]
] |
quant-ph/9903098 | Lauro Tomio | F A B Coutinho, Y Nogami and Lauro Tomio | Many-body system with a four-parameter family of point interactions in
one dimension | 8 pages, 4 figures | J.Phys.A32:4931-4942,1999 | 10.1088/0305-4470/32/26/311 | IFT-P.016/99 | quant-ph math-ph math.MP | null | We consider a four-parameter family of point interactions in one dimension.
This family is a generalization of the usual $\delta$-function potential. We
examine a system consisting of many particles of equal masses that are
interacting pairwise through such a generalized point interaction. We follow
McGuire who obtained exact solutions for the system when the interaction is the
$\delta$-function potential. We find exact bound states with the four-parameter
family. For the scattering problem, however, we have not been so successful.
This is because, as we point out, the condition of no diffraction that is
crucial in McGuire's method is not satisfied except when the four-parameter
family is essentially reduced to the $\delta$-function potential.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 17:15:12 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Coutinho",
"F A B",
""
],
[
"Nogami",
"Y",
""
],
[
"Tomio",
"Lauro",
""
]
] |
quant-ph/9903099 | Daniel Gottesman | Daniel Gottesman | Fault-Tolerant Quantum Computation with Local Gates | 14 pages, LaTeX | J.Mod.Opt. 47 (2000) 333-345 | 10.1080/09500340008244046 | null | quant-ph | null | I discuss how to perform fault-tolerant quantum computation with concatenated
codes using local gates in small numbers of dimensions. I show that a threshold
result still exists in three, two, or one dimensions when
next-to-nearest-neighbor gates are available, and present explicit
constructions. In two or three dimensions, I also show how nearest-neighbor
gates can give a threshold result. In all cases, I simply demonstrate that a
threshold exists, and do not attempt to optimize the error correction circuit
or determine the exact value of the threshold. The additional overhead due to
the fault-tolerance in both space and time is polylogarithmic in the error rate
per logical gate.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 20:21:30 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Gottesman",
"Daniel",
""
]
] |
quant-ph/9903100 | null | annotated by A. Angelow, M.-C. Batoni | About Heisenberg Uncertainty Relation (by E.Schrodinger) | LaTex, 10 pages, no figures; minor corrections | Bulg.J.Phys. 26 (1999) 193-203;
Sitzungsber.Preuss.Akad.Wiss.Berlin (Math.Phys.) 19 (1930) 296-303 | null | ISSP January 99, IFT March 99 | quant-ph | null | The original Schrodinger's paper is translated and annotated in honour of the
70-th anniversary of his Uncertainty Relation [published also in: Bulg. Journal
of Physics,vol.26,no.5/6 (1999) pp.193-203]. In the annotation it is shown that
the Uncertainty Relation can be written in a complete compact canonical form.
| [
{
"version": "v1",
"created": "Tue, 30 Mar 1999 20:38:03 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Jun 2000 10:33:37 GMT"
},
{
"version": "v3",
"created": "Fri, 23 May 2008 18:10:16 GMT"
}
] | 2008-05-23T00:00:00 | [
[
"Angelow",
"annotated by A.",
""
],
[
"Batoni",
"M. -C.",
""
]
] |
quant-ph/9903101 | Ruediger Schack | R. Schack (Royal Holloway, University of London) and C. M. Caves
(University of New Mexico) | Classical model for bulk-ensemble NMR quantum computation | 14 pages, no figures, revtex | Phys.Rev.A60:4354-4362,1999 | 10.1103/PhysRevA.60.4354 | null | quant-ph | null | We present a classical model for bulk-ensemble NMR quantum computation: the
quantum state of the NMR sample is described by a probability distribution over
the orientations of classical tops, and quantum gates are described by
classical transition probabilities. All NMR quantum computing experiments
performed so far with three quantum bits can be accounted for in this classical
model. After a few entangling gates, the classical model suffers an exponential
decrease of the measured signal, whereas there is no corresponding decrease in
the quantum description. We suggest that for small numbers of quantum bits, the
quantum nature of NMR quantum computation lies in the ability to avoid an
exponential signal decrease.
| [
{
"version": "v1",
"created": "Wed, 31 Mar 1999 07:35:38 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Apr 1999 14:19:32 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Schack",
"R.",
"",
"Royal Holloway, University of London"
],
[
"Caves",
"C. M.",
"",
"University of New Mexico"
]
] |
quant-ph/9903102 | Paolo Facchi | P. Facchi, A.G. Klein, S. Pascazio and L.S. Schulman | Berry phase from a quantum Zeno effect | 13 pages, 2 figures | Phys.Lett. A257 (1999) 232-240 | 10.1016/S0375-9601(99)00323-0 | null | quant-ph | null | We exhibit a specific implementation of the creation of geometrical phase
through the state-space evolution generated by the dynamic quantum Zeno effect.
That is, a system is guided through a closed loop in Hilbert space by means a
sequence of closely spaced projections leading to a phase difference with
respect to the original state. Our goal is the proposal of a specific
experimental setup in which this phase could be created and observed. To this
end we study the case of neutron spin, examine the practical aspects of
realizing the "projections," and estimate the difference between the idealized
projections and the experimental implementation.
| [
{
"version": "v1",
"created": "Wed, 31 Mar 1999 10:34:59 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Facchi",
"P.",
""
],
[
"Klein",
"A. G.",
""
],
[
"Pascazio",
"S.",
""
],
[
"Schulman",
"L. S.",
""
]
] |
quant-ph/9903103 | Stefan Weigert | Stefan Weigert | Quantum Time Evolution in Terms of Nonredundant Expectation Values | Latex, 8 pages | Phys.Rev.Lett.84:802,2000 | 10.1103/PhysRevLett.84.802 | null | quant-ph | null | Each scheme of state reconstruction comes down to parametrize the state of a
quantum system by expectation values or probabilities directly measurable in an
experiment. It is argued that the time evolution of these quantities provides
an unambiguous description of the quantal dynamics. This is shown explicitly
for a single spin s, using a quorum of expectation values which contains no
redundant information. The quantum mechanical time evolution of the system is
rephrased in terms of a closed set of linear first-order differential equations
coupling (2s+1)^2 expectation values. This `realization' of the dynamical law
refers neither to the wavefunction of the system nor to its statistical
operator.
| [
{
"version": "v1",
"created": "Wed, 31 Mar 1999 11:15:17 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Weigert",
"Stefan",
""
]
] |
quant-ph/9904001 | Dr Matthew J. Donald | Matthew J. Donald | Progress in a Many-Minds Interpretation of Quantum Theory | 63 pages. Plain TeX. No macros required. Other papers from
http://www.poco.phy.cam.ac.uk/~mjd1014 | null | null | null | quant-ph | null | In a series of papers, a many-minds interpretation of quantum theory has been
developed. The aim in these papers is to present an explicit mathematical
formalism which constitutes a complete theory compatible with relativistic
quantum field theory. In this paper, which could also serve as an introduction
to the earlier papers, three issues are discussed. First, a significant, but
fairly straightforward, revision in some of the technical details is proposed.
This is used as an opportunity to introduce the formalism. Then the
probabilistic structure of the theory is revised, and it is proposed that the
experience of an individual observer can be modelled as the experience of
observing a particular, identified, discrete stochastic process. Finally, it is
argued that the formalism can be modified to give a physics in which no
constants are required. Instead, `constants' have to be determined by
observation, and are fixed only to the extent to which they have been observed.
| [
{
"version": "v1",
"created": "Thu, 1 Apr 1999 11:07:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Donald",
"Matthew J.",
""
]
] |
quant-ph/9904002 | Samuel L. Braunstein | Samuel L. Braunstein | Squeezing as an irreducible resource | 4 pages, 3 figures, new title, removed the fat! | Phys.Rev.A71:055801,2005 | 10.1103/PhysRevA.71.055801 | null | quant-ph | null | We show that squeezing is an irreducible resource which remains invariant
under transformations by linear optical elements. In particular, we give a
decomposition of any optical circuit with linear input-output relations into a
linear multiport interferometer followed by a unique set of single mode
squeezers and then another multiport interferometer. Using this decomposition
we derive a no-go theorem for superpositions of macroscopically distinct states
from single-photon detection. Further, we demonstrate the equivalence between
several schemes for randomly creating polarization-entangled states. Finally,
we derive minimal quantum optical circuits for ideal quantum non-demolition
coupling of quadrature-phase amplitudes.
| [
{
"version": "v1",
"created": "Thu, 1 Apr 1999 12:34:35 GMT"
},
{
"version": "v2",
"created": "Mon, 31 May 1999 19:23:53 GMT"
}
] | 2009-12-10T00:00:00 | [
[
"Braunstein",
"Samuel L.",
""
]
] |
quant-ph/9904003 | Jos Uffink | Jos Uffink and Jan Hilgevoord | Interference and Distinguishability in Quantum Mechanics | In view of the recent debates in Nature and New Scientist on the
question whether Heisenberg's uncertainty relations are strong enough to
explain complementarity in a double-slit experiment, we have decided to make
this 11 year old paper available as e-print. A few misprints have been
corrected and 2 footnotes added | Physica B151 (1988) 309 | null | null | quant-ph | null | Quantitative measures are introduced for the indistinguishability $U$ of two
quantum states in a given measurement and the amount of interference $I$
observable in this measurement. It is shown that these measures obey an
inequality $U\geq I$ which can be seen as an exact formulation of Bohr's claim
that one cannot distinguish between two possible paths of a particle while
maintaining an interference phenomenon. This formulation is applied to a
neutron interferometer experiment of Badurek e.a. It is shown that the
formulation is stronger than an argument based on an uncertainty relation for
phase and photon number considered by these authors.
| [
{
"version": "v1",
"created": "Thu, 1 Apr 1999 17:53:55 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Uffink",
"Jos",
""
],
[
"Hilgevoord",
"Jan",
""
]
] |
quant-ph/9904004 | Don N. Page | Don N. Page (CIAR Cosmology Program, University of Alberta) | Observational Consequences of Many-Worlds Quantum Theory | 8 pages, no figures, LaTeX. Messages from Jerry Finkelstein and
Jacques Mallah have led me to realize that, although I stand by my prediction
that in a many-worlds theory you will be alive in the year 2100 in some
worlds, paradoxically the evidence you will have then will not support
many-worlds quantum theory over single-history quantum theory, since in
either theory it will be evidence of very low measure and likelihood for a
random observation. Therefore, I deleted this part of the paper (and
shortened other parts) | null | null | Alberta-Thy-04-99 | quant-ph gr-qc hep-th | null | Contrary to an oft-made claim, there can be observational distinctions (say
for the expansion of the universe or the cosmological constant) between
"single-history" quantum theories and "many-worlds" quantum theories. The
distinctions occur when the number of observers is not uniquely predicted by
the theory. In single-history theories, each history is weighted simply by its
quantum-mechanical probability, but in many-worlds theories in which random
observations are considered, there should also be the weighting by the numbers
or amounts of observations occurring in each history.
| [
{
"version": "v1",
"created": "Thu, 1 Apr 1999 17:17:55 GMT"
},
{
"version": "v2",
"created": "Mon, 3 May 1999 22:03:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Page",
"Don N.",
"",
"CIAR Cosmology Program, University of Alberta"
]
] |
quant-ph/9904005 | Ashish Thapliyal | David P. DiVincenzo, Barbara M. Terhal, and Ashish V. Thapliyal | Optimal Decompositions of Barely Separable States | 14 Pages (RevTeX), 1 figure (eps). Submitted to the special issue of
the J. Mod. Opt. V2: Change in terminology from "ensemble length" to
"ensemble cardinality" | null | 10.1080/09500340008244049 | null | quant-ph | null | Two families of bipartite mixed quantum states are studied for which it is
proved that the number of members in the optimal-decomposition ensemble --- the
ensemble realizing the entanglement of formation --- is greater than the rank
of the mixed state. We find examples for which the number of states in this
optimal ensemble can be larger than the rank by an arbitrarily large factor. In
one case the proof relies on the fact that the partial transpose of the mixed
state has zero eigenvalues; in the other case the result arises from the
properties of product bases that are completable only by embedding in a larger
Hilbert space.
| [
{
"version": "v1",
"created": "Thu, 1 Apr 1999 18:56:04 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Sep 1999 14:41:40 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"DiVincenzo",
"David P.",
""
],
[
"Terhal",
"Barbara M.",
""
],
[
"Thapliyal",
"Ashish V.",
""
]
] |
quant-ph/9904006 | Chris Adami | C. Adami and N.J. Cerf (Caltech) | Prolegomena to a non-equilibrium quantum statistical mechanics | 20 pages, LaTeX with elsart.cls, 8 postscript figures. Special issue
on quantum computation of Chaos, Solitons, and Fractals | Chaos Solitons Fractals 10 (1999) 1637-1650 | null | null | quant-ph gr-qc | null | We suggest that the framework of quantum information theory, which has been
developing rapidly in recent years due to intense activity in quantum
computation and quantum communication, is a reasonable starting point to study
non-equilibrium quantum statistical phenomena. As an application, we discuss
the non-equilibrium quantum thermodynamics of black hole formation and
evaporation.
| [
{
"version": "v1",
"created": "Thu, 1 Apr 1999 21:00:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Adami",
"C.",
"",
"Caltech"
],
[
"Cerf",
"N. J.",
"",
"Caltech"
]
] |
quant-ph/9904007 | Haret Rosu | H.C. Rosu | Multiple parameter structure of Mielnik's isospectrality in unbroken
SUSYQM | 12 pages, 5 figures | Int. J. Theor. Phys. 39 (January 2000) 105-114 | null | null | quant-ph math-ph math.MP | null | Within unbroken SUSYQM and for zero factorization energy, I present an
iterative generalization of Mielnik's isospectral method by employing a
Schroedinger true zero mode in the first-step general Riccati solution and
imposing the physical condition of normalization at each iterative step. This
procedure leads to a well-defined multiple-parameter structure within Mielnik's
construction for both zero modes and potentials
| [
{
"version": "v1",
"created": "Fri, 2 Apr 1999 00:16:20 GMT"
},
{
"version": "v2",
"created": "Tue, 6 Apr 1999 14:51:34 GMT"
},
{
"version": "v3",
"created": "Fri, 16 Apr 1999 21:09:16 GMT"
},
{
"version": "v4",
"created": "Sat, 17 Apr 1999 01:39:33 GMT"
},
{
"version": "v5",
"created": "Wed, 21 Apr 1999 03:50:32 GMT"
},
{
"version": "v6",
"created": "Mon, 10 May 1999 01:21:27 GMT"
},
{
"version": "v7",
"created": "Thu, 13 May 1999 22:28:24 GMT"
},
{
"version": "v8",
"created": "Thu, 27 Jan 2000 00:03:29 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Rosu",
"H. C.",
""
]
] |
quant-ph/9904008 | Stefano Liberati | S.Liberati, Matt Visser, F.Belgiorno, D.W.Sciama | Sonoluminescence and the QED vacuum | 15 pages, 1 figure, uses sprocl.sty. Talk at the 4th Workshop on
Quantum Field Theory Under the Influence of External Conditions, Leipzig,
14-18 September, 1998 | null | null | SISSA-ref 131/98/A | quant-ph hep-ph hep-th | null | In this talk I shall describe an extension of the quantum-vacuum approach to
sonoluminescence proposed several years ago by J.Schwinger. We shall first
consider a model calculation based on Bogolubov coefficients relating the QED
vacuum in the presence of an expanded bubble to that in the presence of a
collapsed bubble. In this way we shall derive an estimate for the spectrum and
total energy emitted. This latter will be shown to be proportional to the
volume of space over which the refractive index changes, as Schwinger
predicted. After this preliminary check we shall deal with the physical
constraints that any viable dynamical model for SL has to satisfy in order to
fit the experimental data. We shall emphasize the importance of the timescale
of the change in refractive index. This discussion will led us to propose a
somewhat different version of dynamical Casimir effect in which the change in
volume of the bubble is no longer the only source for the change in the
refractive index.
| [
{
"version": "v1",
"created": "Fri, 2 Apr 1999 02:48:38 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Liberati",
"S.",
""
],
[
"Visser",
"Matt",
""
],
[
"Belgiorno",
"F.",
""
],
[
"Sciama",
"D. W.",
""
]
] |
quant-ph/9904009 | Boris F. Samsonov | Boris F. Samsonov | New possibilities for supersymmetry breakdown in quantum mechanics and
second order irreducible Darboux transformations | null | Phys.Lett. A263 (1999) 274-280 | 10.1016/S0375-9601(99)00736-7 | null | quant-ph | null | New types of irreducible second order Darboux transformations for the one
dimensional Schroedinger equation are described. The main feature of such
transformations is that the transformation functions have the eigenvalues
grater then the ground state energy of the initial (or reference) Hamiltonian.
When such a transformation is presented as a chain of two first order
transformations, an intermediate potential is singular and therefore
intermediate Hamiltonian can not be Hermitian while the final potential is
regular and the final Hamiltonian is Hermitian. Second derivative
supersymmetric quantum mechanical model based on a transformation of this kind
exhibits properties inherent to models with exact and broken supersymmetry at
once.
| [
{
"version": "v1",
"created": "Fri, 2 Apr 1999 03:13:02 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Samsonov",
"Boris F.",
""
]
] |
quant-ph/9904010 | Hans J. Briegel | H.-J. Briegel, T. Calarco, D. Jaksch, J. I. Cirac, and P. Zoller | Quantum computing with neutral atoms | 21 pages, 19 figures | null | 10.1080/09500340008244052 | null | quant-ph | null | We develop a method to entangle neutral atoms using cold controlled
collisions. We analyze this method in two particular set-ups: optical lattices
and magnetic micro-traps. Both offer the possibility of performing certain
multi-particle operations in parallel. Using this fact, we show how to
implement efficient quantum error correction and schemes for fault-tolerant
computing.
| [
{
"version": "v1",
"created": "Fri, 2 Apr 1999 13:11:49 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Briegel",
"H. -J.",
""
],
[
"Calarco",
"T.",
""
],
[
"Jaksch",
"D.",
""
],
[
"Cirac",
"J. I.",
""
],
[
"Zoller",
"P.",
""
]
] |
quant-ph/9904011 | Zanardi Paolo | Paolo Zanardi (1) (2), Mario Rasetti (2) (3) ((1)Unit\`a INFM,
Politecnico di Torino, (2) ISI Foundation, Torino (3) Dipartimento di Fisica
Politecnico di Torino) | Holonomic Quantum Computation | Presentation improved, accepted by Phys. Lett. A, 5 pages LaTeX, no
figures | Phys.Lett. A264 (1999) 94-99 | 10.1016/S0375-9601(99)00803-8 | null | quant-ph hep-th | null | We show that the notion of generalized Berry phase i.e., non-abelian
holonomy, can be used for enabling quantum computation. The computational space
is realized by a $n$-fold degenerate eigenspace of a family of Hamiltonians
parametrized by a manifold $\cal M$. The point of $\cal M$ represents classical
configuration of control fields and, for multi-partite systems, couplings
between subsystem. Adiabatic loops in the control $\cal M$ induce non trivial
unitary transformations on the computational space. For a generic system it is
shown that this mechanism allows for universal quantum computation by composing
a generic pair of loops in $\cal M.$
| [
{
"version": "v1",
"created": "Fri, 2 Apr 1999 17:24:45 GMT"
},
{
"version": "v2",
"created": "Sat, 3 Apr 1999 13:29:19 GMT"
},
{
"version": "v3",
"created": "Mon, 15 Nov 1999 18:27:52 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Zanardi",
"Paolo",
""
],
[
"Rasetti",
"Mario",
""
]
] |
quant-ph/9904012 | Jung-Hoon Kim | Jung-Hoon Kim and Hai-Woong Lee | Canonical Transformations and the Hamilton-Jacobi Theory in Quantum
Mechanics | 12 pages, no figures, REVTeX; Notes added | Can.J.Phys. 77 (1999) 411-425 | 10.1139/cjp-77-6-411 | null | quant-ph | null | Canonical transformations using the idea of quantum generating functions are
applied to construct a quantum Hamilton-Jacobi theory, based on the analogy
with the classical case. An operator and a c-number forms of the time-dependent
quantum Hamilton-Jacobi equation are derived and used to find dynamical
solutions of quantum problems. The phase-space picture of quantum mechanics is
discussed in connection with the present theory.
| [
{
"version": "v1",
"created": "Sun, 4 Apr 1999 02:50:50 GMT"
},
{
"version": "v2",
"created": "Sun, 14 May 2000 05:48:15 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Kim",
"Jung-Hoon",
""
],
[
"Lee",
"Hai-Woong",
""
]
] |
quant-ph/9904013 | Matt Visser | Stefano Liberati (SISSA, Trieste), Matt Visser (Washington University,
St Louis), Francesco Belgiorno (Milano), Dennis Sciama (SISSA, ICTP, Trieste;
Oxford) | Sonoluminescence as a QED vacuum effect. I: The Physical Scenario | 25 pages, LaTeX 209, ReV-TeX 3.2, eight figures. Minor revisions:
Typos fixed, references updated, minor changes in numerical estimates, minor
changes in some figures | Phys.Rev. D61 (2000) 085023 | 10.1103/PhysRevD.61.085023 | null | quant-ph cond-mat hep-ph hep-th | null | Several years ago Schwinger proposed a physical mechanism for
sonoluminescence in terms of changes in the properties of the
quantum-electrodynamic (QED) vacuum state. This mechanism is most often phrased
in terms of changes in the Casimir Energy: changes in the distribution of
zero-point energies and has recently been the subject of considerable
controversy. The present paper further develops this quantum-vacuum approach to
sonoluminescence: We calculate Bogolubov coefficients relating the QED vacuum
states in the presence of a homogeneous medium of changing dielectric constant.
In this way we derive an estimate for the spectrum, number of photons, and
total energy emitted. We emphasize the importance of rapid spatio-temporal
changes in refractive indices, and the delicate sensitivity of the emitted
radiation to the precise dependence of the refractive index as a function of
wavenumber, pressure, temperature, and noble gas admixture. Although the
physics of the dynamical Casimir effect is a universal phenomenon of QED,
specific experimental features are encoded in the condensed matter physics
controlling the details of the refractive index. This calculation places rather
tight constraints on the possibility of using the dynamical Casimir effect as
an explanation for sonoluminescence, and we are hopeful that this scenario will
soon be amenable to direct experimental probes. In a companion paper we discuss
the technical complications due to finite-size effects, but for reasons of
clarity in this paper we confine attention to bulk effects.
| [
{
"version": "v1",
"created": "Mon, 5 Apr 1999 19:24:56 GMT"
},
{
"version": "v2",
"created": "Mon, 10 May 1999 16:51:17 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Liberati",
"Stefano",
"",
"SISSA, Trieste"
],
[
"Visser",
"Matt",
"",
"Washington University,\n St Louis"
],
[
"Belgiorno",
"Francesco",
"",
"Milano"
],
[
"Sciama",
"Dennis",
"",
"SISSA, ICTP, Trieste;\n Oxford"
]
] |
quant-ph/9904014 | Paul Slater | Paul B. Slater (University of California) | Monotonicity Properties of Certain Measures over the Two-Level Quantum
Systems | 4 pages, LaTeX. minor changes | Lett. Math. Phys. 52: 343-348, 2000. | null | null | quant-ph | null | We demonstrate --- using the case of the two-dimensional quantum systems ---
that the "natural measure on the space of density matrices describing
N-dimensional quantum systems" proposed by Zyczkowski et al (quant-ph/9804024)
does not belong to the class of normalized volume elements of monotone metrics
on the quantum systems. Such metrics possess the statistically important
property of being decreasing under stochastic mappings (coarse-grainings). We
do note that the proposed natural measure (and certain evident variations upon
it) exhibit quite specific monotonicity properties, but not of the form
required for membership in the class.
| [
{
"version": "v1",
"created": "Mon, 5 Apr 1999 22:45:58 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Apr 1999 19:46:53 GMT"
},
{
"version": "v3",
"created": "Thu, 10 Jun 1999 22:03:15 GMT"
},
{
"version": "v4",
"created": "Tue, 25 Apr 2000 16:19:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Slater",
"Paul B.",
"",
"University of California"
]
] |
quant-ph/9904015 | Stefan Scheel | S.Scheel, L.Knoll, D.G.Welsch | Spontaneous decay of an excited atom in an absorbing dielectric | 28 pages, 6 figures, typeset using RevTeX | null | 10.1103/PhysRevA.60.4094 | null | quant-ph | null | Starting from the quantized version of Maxwell's equations for the
electromagnetic field in an arbitrary linear Kramers-Kronig dielectric,
spontaneous decay of the excited state of a two-level atom embedded in a
dispersive and absorbing medium is studied and the decay rate is calculated.
The calculations are performed for both the (Clausius-Mosotti) virtual cavity
model and the (Glauber-Lewenstein) real cavity model. It is shown that owing to
nonradiative decay associated with absorption the rate of spontaneous decay
sensitively depends on the cavity radius when the atomic transition frequency
approaches an absorption band of the medium. Only when the effect of absorption
is fully disregarded, then the familiar local-field correction factors are
recovered.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 13:54:42 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Scheel",
"S.",
""
],
[
"Knoll",
"L.",
""
],
[
"Welsch",
"D. G.",
""
]
] |
quant-ph/9904016 | Wolfgang Luecke | W. Luecke | Nonlocality in Nonlinear Quantum Mechanics | 10 pages, LaTeX2e file, 1 figure in PicTeX, misprints corrected | null | null | ASI-TPA/1/99 | quant-ph | null | A general method for testing essential nonlocality of nonlinear modifications
of quantum mechanics is presented and applied to show the inconsistency of I.
Bialynicki-Birula's and J. Mycielski's nonlinear quantum theory.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 14:35:36 GMT"
},
{
"version": "v2",
"created": "Sat, 11 Sep 1999 11:06:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Luecke",
"W.",
""
]
] |
quant-ph/9904017 | Eduard Schmidt | Eduard Schmidt, Ludwig Knoll, and Dirk-Gunnar Welsch | Nonclassical correlations in damped quantum solitons | 15 pages, 11 PS figures (color) | null | 10.1088/1464-4266/2/4/301 | QO-03/99 | quant-ph | null | Using cumulant expansion in Gaussian approximation, the internal quantum
statistics of damped soliton-like pulses in Kerr media are studied numerically,
considering both narrow and finite bandwidth spectral pulse components. It is
shown that the sub-Poissonian statistics can be enhanced, under certain
circumstances, by absorption, which damps out some destructive interferences.
Further, it is shown that both the photon-number correlation and the
correlation of the photon-number variance between different pulse components
can be highly nonclassical even for an absorbing fiber. Optimum frequency
windows are determined in order to realize strong nonclassical behavior, which
offers novel possibilities of using solitons in optical fibers as a source of
nonclassically correlated light beams.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 15:40:09 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Apr 1999 19:48:14 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Schmidt",
"Eduard",
""
],
[
"Knoll",
"Ludwig",
""
],
[
"Welsch",
"Dirk-Gunnar",
""
]
] |
quant-ph/9904018 | Matt Visser | Francesco Belgiorno (Milano), Stefano Liberati (SISSA, Trieste), Matt
Visser (Washington University, St Louis), Dennis Sciama (SISSA, ICTP,
Trieste; Oxford) | Sonoluminescence: Two-photon correlations as a test of thermality | 6 pages, revtex 3; revised to include more discussion of finite
volume effects; physics conclusions unchanged; to appear in Physics Letters A | Phys.Lett. A271 (2000) 308-313 | 10.1016/S0375-9601(00)00394-7 | null | quant-ph cond-mat hep-ph hep-th | null | In this Letter we propose a fundamental test for probing the thermal nature
of the spectrum emitted by sonoluminescence. We show that two-photon
correlations can in principle discriminate between real thermal light and the
quasi-thermal squeezed-state photons typical of models based on the dynamic
Casimir effect. Two-photon correlations provide a powerful experimental test
for various classes of sonoluminescence models.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 16:42:01 GMT"
},
{
"version": "v2",
"created": "Fri, 2 Jun 2000 23:22:40 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Belgiorno",
"Francesco",
"",
"Milano"
],
[
"Liberati",
"Stefano",
"",
"SISSA, Trieste"
],
[
"Visser",
"Matt",
"",
"Washington University, St Louis"
],
[
"Sciama",
"Dennis",
"",
"SISSA, ICTP,\n Trieste; Oxford"
]
] |
quant-ph/9904019 | Juan F. Poyatos | Juan F. Poyatos and Gonzalo Garcia de Polavieja | Quantum-Classical Correspondence: Controlling Quantum Transport by State
Synthesis in Ion Traps | 4 pages, 3 eps figures | null | null | null | quant-ph | null | A procedure to enhance the quantum--classical correspondence even in
situations far from the classical limit is proposed. It is based on controlling
the quantum transport between classical regions using the capability to
synthesize arbitrary motional states in ion traps. Quantum barriers and
passages to transport can be created selecting the relevant frequencies. This
technique is then applied to stabilize the quantum motion onto classical
structures or alter the dynamical tunneling in nonintegrable systems.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 16:52:03 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Poyatos",
"Juan F.",
""
],
[
"de Polavieja",
"Gonzalo Garcia",
""
]
] |
quant-ph/9904020 | Paolo Facchi | P. Facchi and S. Pascazio | Deviations from exponential law and Van Hove's "\lambda^2 t" limit | 18 pages, 3 figures | Physica A271 (1999) 133-146 | 10.1016/S0378-4371(99)00209-5 | null | quant-ph | null | The deviations from a purely exponential behavior in a decay process are
analyzed in relation to Van Hove's "\lambda^2 t" limiting procedure. Our
attention is focused on the effects that arise when the coupling constant is
small but nonvanishing. We first consider a simple model (two-level atom in
interaction with the electromagnetic field), then gradually extend our analysis
to a more general framework. We estimate all deviations from exponential
behavior at leading orders in the coupling constant.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 16:53:47 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Facchi",
"P.",
""
],
[
"Pascazio",
"S.",
""
]
] |
quant-ph/9904021 | John Preskill | Andrew M. Childs, John Preskill, and Joseph Renes (Caltech) | Quantum information and precision measurement | 13 pages, 1 figure, proof of conjecture added | J.Mod.Opt. 47 (2000) 155-176 | 10.1080/09500340008244034 | CALT-68-2217 | quant-ph | null | We describe some applications of quantum information theory to the analysis
of quantum limits on measurement sensitivity. A measurement of a weak force
acting on a quantum system is a determination of a classical parameter
appearing in the master equation that governs the evolution of the system;
limitations on measurement accuracy arise because it is not possible to
distinguish perfectly among the different possible values of this parameter.
Tools developed in the study of quantum information and computation can be
exploited to improve the precision of physics experiments; examples include
superdense coding, fast database search, and the quantum Fourier transform.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 17:58:17 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Apr 1999 23:00:57 GMT"
}
] | 2012-03-28T00:00:00 | [
[
"Childs",
"Andrew M.",
"",
"Caltech"
],
[
"Preskill",
"John",
"",
"Caltech"
],
[
"Renes",
"Joseph",
"",
"Caltech"
]
] |
quant-ph/9904022 | John Preskill | John Preskill (Caltech) | Quantum information and physics: some future directions | 7 pages, references added | J.Mod.Opt. 47 (2000) 127-137 | 10.1080/09500340008244031 | CALT-68-2219 | quant-ph cond-mat.str-el gr-qc hep-th | null | I consider some promising future directions for quantum information theory
that could influence the development of 21st century physics. Advances in the
theory of the distinguishability of superoperators may lead to new strategies
for improving the precision of quantum-limited measurements. A better grasp of
the properties of multi-partite quantum entanglement may lead to deeper
understanding of strongly-coupled dynamics in quantum many-body systems,
quantum field theory, and quantum gravity.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 18:22:41 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Apr 1999 03:38:18 GMT"
},
{
"version": "v3",
"created": "Fri, 30 Apr 1999 22:48:43 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Preskill",
"John",
"",
"Caltech"
]
] |
quant-ph/9904023 | Charles H. Bennett | Charles H. Bennett, Peter W. Shor, John A. Smolin, and Ashish V.
Thapliyal | Entanglement-Assisted Classical Capacity of Noisy Quantum Channels | 4 pages including 3 figures. Eq 4 restored to be an equality, not
merely the lower bound claimed in v4; reference added; one figure removed to
save space | Phys.Rev.Lett.83:3081,1999 | 10.1103/PhysRevLett.83.3081 | null | quant-ph | null | Prior entanglement between sender and receiver, which exactly doubles the
classical capacity of a noiseless quantum channel, can increase the classical
capacity of some noisy quantum channels by an arbitrarily large constant factor
depending on the channel, relative to the best known classical capacity
achievable without entanglement. The enhancement factor is greatest for very
noisy channels, with positive classical capacity but zero quantum capacity.
Although such quantum channels can be simulated classically, no violation of
causality is implied, because the simulation requires at least as much forward
classical communication as the entanglement-assisted classical capacity of the
channel being simulated. We obtain exact expressions for the
entanglement-assisted capacity of depolarizing and erasure channels in d
dimensions.
| [
{
"version": "v1",
"created": "Tue, 6 Apr 1999 20:51:41 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Apr 1999 20:45:55 GMT"
},
{
"version": "v3",
"created": "Wed, 19 May 1999 16:05:21 GMT"
},
{
"version": "v4",
"created": "Wed, 23 Jun 1999 22:09:36 GMT"
},
{
"version": "v5",
"created": "Tue, 17 Aug 1999 19:00:29 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Bennett",
"Charles H.",
""
],
[
"Shor",
"Peter W.",
""
],
[
"Smolin",
"John A.",
""
],
[
"Thapliyal",
"Ashish V.",
""
]
] |
quant-ph/9904024 | Yuri Ozhigov | G. L. Litvinov, V. P. Maslov, A. Ya. Rodionov | Unifying Approach to Software and Hardware Design for Scientific
Calculations | Latex, 18 pages, no figures; references are updated in this version | null | null | null | quant-ph | null | A unifying approach to software and hardware design generated by ideas of
Idempotent Mathematics is discussed. The so-called idempotent correspondence
principle for algorithms, programs and hardware units is described. A software
project based on this approach is presented.
Key words: universal algorithms, idempotent calculus, software design,
hardware design, object oriented programming
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 05:09:18 GMT"
},
{
"version": "v2",
"created": "Fri, 9 Feb 2001 10:00:36 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Litvinov",
"G. L.",
""
],
[
"Maslov",
"V. P.",
""
],
[
"Rodionov",
"A. Ya.",
""
]
] |
quant-ph/9904025 | Yuri Ozhigov | Grigori Litvinov, Viktor Maslov, Grigori Shpiz | Nondigital implementation of the arithmetic of real numbers by means of
quantum computer media | Amstex, 9 pages, no figures; bibliography revised, style and language
revised, journal ref. added; some acknowledgements added, authors' e-mail
address updated; TeX formatting changed, Report-No added | Math.Notes 70 (2001) 53-60 | null | ESI 1115 | quant-ph | null | In the framework of a model for quantum computer media, a nondigital
implementation of the arithmetic of the real numbers is described. For this
model, an elementary storage "cell" is an ensemble of qubits (quantum bits). It
is found that to store an arbitrary real number it is sufficient to use four of
these ensembles and the arithmetic operations can be implemented by fixed
quantum circuits.
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 05:09:37 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Feb 2001 10:47:50 GMT"
},
{
"version": "v3",
"created": "Tue, 18 Sep 2001 12:59:06 GMT"
},
{
"version": "v4",
"created": "Sun, 30 Dec 2001 12:13:49 GMT"
},
{
"version": "v5",
"created": "Thu, 17 Jan 2002 21:36:08 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Litvinov",
"Grigori",
""
],
[
"Maslov",
"Viktor",
""
],
[
"Shpiz",
"Grigori",
""
]
] |
quant-ph/9904026 | Ali Mostafazadeh | Ali Mostafazadeh | Generalized Adiabatic Product Expansion: A nonperturbative method of
solving time-dependent Schroedinger equation | 19 pages, accepted for publication in J. Math. Phys | J.Math.Phys. 40 (1999) 3311-3326 | 10.1063/1.532889 | Koc University preprint Spring 1999 | quant-ph gr-qc hep-th | null | We outline a method based on successive canonical transformations which
yields a product expansion for the evolution operator of a general (possibly
non-Hermitian) Hamiltonian. For a class of such Hamiltonians this expansion
involves a finite number of terms, and our method gives the exact solution of
the corresponding time-dependent Schroedinger equation. We apply this method to
study the dynamics of a general nondegenerate two-level quantum system, a
time-dependent classical harmonic oscillator, and a degenerate system
consisting of a spin 1 particle interacting with a time-dependent electric
field E(t) through the Stark Hamiltonian H=\lambda [J.E(t)]^2.
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 10:32:48 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Mostafazadeh",
"Ali",
""
]
] |
quant-ph/9904027 | Xiao-Guang Wang | Xiao-Guang Wang, Shao-Hua Pan and Guo-Zhen Yang | Non-classical properties and algebraic characteristics of negative
binomial states in quantized radiation fields | 17 pages, 5 figures, Accepted in EPJ D | Eur.Phys.J.D10:415-422,2000 | 10.1007/s100530050564 | null | quant-ph | null | We study the nonclassical properties and algebraic characteristics of the
negative binomial states introduced by Barnett recently. The ladder operator
formalism and displacement operator formalism of the negative binomial states
are found and the algebra involved turns out to be the SU(1,1) Lie algebra via
the generalized Holstein-Primarkoff realization. These states are essentially
Peremolov's SU(1,1) coherent states. We reveal their connection with the
geometric states and find that they are excited geometric states. As
intermediate states, they interpolate between the number states and geometric
states. We also point out that they can be recognized as the nonlinear coherent
states. Their nonclassical properties, such as sub-Poissonian distribution and
squeezing effect are discussed. The quasiprobability distributions in phase
space, namely the Q and Wigner functions, are studied in detail. We also
propose two methods of generation of the negative binomial states.
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 12:35:02 GMT"
},
{
"version": "v2",
"created": "Mon, 29 Nov 1999 02:39:53 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Wang",
"Xiao-Guang",
""
],
[
"Pan",
"Shao-Hua",
""
],
[
"Yang",
"Guo-Zhen",
""
]
] |
quant-ph/9904028 | J. C. Xavier | C. J. Villas-B\^oas, N. G. de Almeida and M. H. Y. Moussa | Teleportation of a Zero-and One-photon Running Wave State by Projection
Synthesis | 11 pages, 1 figure | null | 10.1103/PhysRevA.60.2759 | null | quant-ph | null | We show how to teleport a running wave superposition of zero- and one-photon
field state through the projection synthesis technique. The fidelity of the
scheme is computed taking into account the noise introduced by dissipation and
the efficiency of the detectors. These error sources have been introduced
through a single general relationship between input and output operators.
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 13:32:31 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Apr 1999 20:37:34 GMT"
},
{
"version": "v3",
"created": "Mon, 12 Apr 1999 22:00:44 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Villas-Bôas",
"C. J.",
""
],
[
"de Almeida",
"N. G.",
""
],
[
"Moussa",
"M. H. Y.",
""
]
] |
quant-ph/9904029 | A. K. Rajagopal | A. K. Rajagopal(1) and Sumiyoshi Abe(2) ((1) Naval Research
Laboratory, Washington, DC, USA (2) College of Science and Technology, Nihon
University, Funabashi, Chiba, Japan) | Implications of Form Invariance to the Structure of Nonextensive
Entropies | 8 pages | Phys.Rev.Lett.83:1711,1999 | 10.1103/PhysRevLett.83.1711 | null | quant-ph cond-mat.stat-mech | null | The form invariance of the statement of the maximum entropy principle and the
metric structure in quantum density matrix theory, when generalized to
nonextensive situations, is shown here to determine the structure of the
nonextensive entropies. This limits the range of the nonextensivity parameter
to so as to preserve the concavity of the entropies. The Tsallis entropy is
thereby found to be appropriately renormalized.
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 14:48:38 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Rajagopal",
"A. K.",
""
],
[
"Abe",
"Sumiyoshi",
""
]
] |
quant-ph/9904030 | Enrique Solano | T. Bastin and E. Solano | Numerical computation of one-photon mazer resonances for arbitrary field
modes | Published version | Comput.Phys.Commun. 124 (2000) 197-203 | 10.1016/S0010-4655(99)00452-X | null | quant-ph | null | We present a novel approach for solving numerically one-dimensional
scattering problems and apply it for computing the emission probability of an
ultracold atom interacting with an arbitrary field mode of a high-$Q$ cavity.
Our method is efficient, stable and succeeds when other numerical integration
methods fail. It also replaces and improves advantageously the WKB
approximation. The cases of sinusoidal, $\mathrm{sech}^2$ and Gaussian field
modes are studied and compared. Divergences with previous works, where WKB was
used, are found.
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 22:37:43 GMT"
},
{
"version": "v2",
"created": "Thu, 4 May 2000 16:32:05 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Bastin",
"T.",
""
],
[
"Solano",
"E.",
""
]
] |
quant-ph/9904031 | Mikhail Lukin | Michael M. Kash, Vladimir A.Sautenkov, Alexander S. Zibrov, L.
Hollberg, George R. Welch, Mikhail D. Lukin, Yuri Rostovtsev, Edward S. Fry,
Marlan O. Scully | Ultra-Slow Light and Enhanced Nonlinear Optical Effects in a Coherently
Driven Hot Atomic Gas | null | null | 10.1103/PhysRevLett.82.5229 | null | quant-ph | null | We report the observation of small group velocities of order 90 meters per
second, and large group delays of greater than 0.26 ms, in an optically dense
hot rubidium gas (~360 K). Media of this kind yield strong nonlinear
interactions between very weak optical fields, and very sharp spectral
features. The result is in agreement with previous studies on nonlinear
spectroscopy of dense coherent media.
| [
{
"version": "v1",
"created": "Wed, 7 Apr 1999 23:57:36 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Kash",
"Michael M.",
""
],
[
"Sautenkov",
"Vladimir A.",
""
],
[
"Zibrov",
"Alexander S.",
""
],
[
"Hollberg",
"L.",
""
],
[
"Welch",
"George R.",
""
],
[
"Lukin",
"Mikhail D.",
""
],
[
"Rostovtsev",
"Yuri",
""
],
[
"Fry",
"Edward S.",
""
],
[
"Scully",
"Marlan O.",
""
]
] |
quant-ph/9904032 | Mikhail Lukin | V. A. Sautenkov, M. D. Lukin, C. J. Bednar, G. R. Welch, M.
Fleischhauer, V. L. Velichansky, and M. O. Scully | Enhancement of Magneto-Optic Effects via Large Atomic Coherence | null | null | 10.1103/PhysRevA.62.023810 | null | quant-ph | null | We utilize the generation of large atomic coherence to enhance the resonant
nonlinear magneto-optic effect by several orders of magnitude, thereby
eliminating power broadening and improving the fundamental signal-to-noise
ratio. A proof-of-principle experiment is carried out in a dense vapor of Rb
atoms. Detailed numerical calculations are in good agreement with the
experimental results. Applications such as optical magnetometry or the search
for violations of parity and time reversal symmetry are feasible.
| [
{
"version": "v1",
"created": "Thu, 8 Apr 1999 00:26:10 GMT"
}
] | 2019-08-17T00:00:00 | [
[
"Sautenkov",
"V. A.",
""
],
[
"Lukin",
"M. D.",
""
],
[
"Bednar",
"C. J.",
""
],
[
"Welch",
"G. R.",
""
],
[
"Fleischhauer",
"M.",
""
],
[
"Velichansky",
"V. L.",
""
],
[
"Scully",
"M. O.",
""
]
] |
quant-ph/9904033 | Howard M. Wiseman | H.M. Wiseman | Squashed States of Light: Theory and Applications to Quantum
Spectroscopy | 8 pages plus one figure. Submitted to JEOS-B for Dan Walls Special
Issue | null | 10.1088/1464-4266/1/4/317 | null | quant-ph | null | Using a feedback loop it is possible to reduce the fluctuations in one
quadrature of an in-loop field without increasing the fluctuations in the
other. This effect has been known for a long time, and has recently been called
``squashing'' [B.C. Buchler et al., Optics Letters {\bf 24}, 259 (1999)], as
opposed to the ``squeezing'' of a free field in which the conjugate
fluctuations are increased. In this paper I present a general theory of
squashing, including simultaneous squashing of both quadratures and
simultaneous squeezing and squashing. I show that a two-level atom coupled to
the in-loop light feels the effect of the fluctuations as calculated by the
theory. In the ideal limit of light squeezed in one quadrature and squashed in
the other, the atomic decay can be completely suppressed.
| [
{
"version": "v1",
"created": "Thu, 8 Apr 1999 00:26:28 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Wiseman",
"H. M.",
""
]
] |
quant-ph/9904034 | Mikhail Lukin | A. S. Zibrov, M. D. Lukin, and M. O. Scully | Parametric Self-Oscillation via Resonantly Enhanced Multiwave Mixing | null | Phys.Rev.Lett.83:4049-4052,1999 | 10.1103/PhysRevLett.83.4049 | null | quant-ph | null | We demonstrate an efficient nonlinear process in which Stokes and anti-Stokes
components are generated spontaneously in a Raman-like, near resonant media
driven by low power counter-propagating fields. Oscillation of this kind does
not require optical cavity and can be viewed as a spontaneous formation of
atomic coherence grating.
| [
{
"version": "v1",
"created": "Thu, 8 Apr 1999 01:04:54 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Zibrov",
"A. S.",
""
],
[
"Lukin",
"M. D.",
""
],
[
"Scully",
"M. O.",
""
]
] |
quant-ph/9904035 | Dr. G. Plunien | I. Goidenko, L. Labzowsky, A. Nefiodov, G. Plunien, G. Soff | The second-order electron self-energy in hydrogen-like ions | 13 LaTex pages, 2 figures | Phys.Rev.Lett.83:2312,1999 | 10.1103/PhysRevLett.83.2312 | null | quant-ph | null | A calculation of the simplest part of the second-order electron self-energy
(loop after loop irreducible contribution) for hydrogen-like ions with nuclear
charge numbers $3 \leq Z \leq 92$ is presented. This serves as a test for the
more complicated second-order self-energy parts (loop inside loop and crossed
loop contributions) for heavy one-electron ions. Our results are in strong
disagreement with recent calculations of Mallampalli and Sapirstein for low $Z$
values but are compatible with the two known terms of the analytical
$Z\alpha$-expansion.
| [
{
"version": "v1",
"created": "Thu, 8 Apr 1999 10:03:08 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Goidenko",
"I.",
""
],
[
"Labzowsky",
"L.",
""
],
[
"Nefiodov",
"A.",
""
],
[
"Plunien",
"G.",
""
],
[
"Soff",
"G.",
""
]
] |
quant-ph/9904036 | Stefan Weigert | Jean-Pierre Amiet and Stefan Weigert | Coherent States and the Reconstruction of Pure Spin States | Latex2e, 8 pages | J. Opt. B 1 (1999) L5 | null | null | quant-ph | null | Coherent states provide an appealing method to reconstruct efficiently a pure
state of a quantum mechanical spin s. A Stern-Gerlach apparatus is used to
measure (4s+1) expectations of projection operators on appropriate coherent
states in the unknown state. These measurements are compatible with a finite
number of states which can be distinguished, in the generic case, by measuring
one more probability. In addition, the present technique shows that the zeroes
of a Husimi distribution do have an operational meaning: they can be identified
directly by measurements with a Stern-Gerlach apparatus. This result comes down
to saying that it is possible to resolve experimentally structures in quantum
phase-space which are smaller than hbar.
| [
{
"version": "v1",
"created": "Thu, 8 Apr 1999 13:42:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Amiet",
"Jean-Pierre",
""
],
[
"Weigert",
"Stefan",
""
]
] |
quant-ph/9904037 | Tez Rudolph | Terry Rudolph | Quantum Information is physical too | 3 pages, LaTex | null | null | null | quant-ph | null | We discuss the physical nature of quantum information, in particular
focussing on tasks that are achievable by some physical realizations of qubits
but not by others.
| [
{
"version": "v1",
"created": "Thu, 8 Apr 1999 21:20:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Rudolph",
"Terry",
""
]
] |
quant-ph/9904038 | Richard J. Hughes | Richard J. Hughes, George L. Morgan and C. Glen Peterson (Los Alamos
National Laboratory) | Practical quantum key distribution over a 48-km optical fiber network | 13 pages, 7 figures, .pdf format submitted to Journal of Modern
Optics | null | 10.1080/09500340008244058 | LA-UR-99-1593 | quant-ph | null | The secure distribution of the secret random bit sequences known as "key"
material, is an essential precursor to their use for the encryption and
decryption of confidential communications. Quantum cryptography is a new
technique for secure key distribution with single-photon transmissions:
Heisenberg's uncertainty principle ensures that an adversary can neither
successfully tap the key transmissions, nor evade detection (eavesdropping
raises the key error rate above a threshold value). We have developed
experimental quantum cryptography systems based on the transmission of
non-orthogonal photon states to generate shared key material over
multi-kilometer optical fiber paths and over line-of-sight links. In both
cases, key material is built up using the transmission of a single-photon per
bit of an initial secret random sequence. A quantum-mechanically random subset
of this sequence is identified, becoming the key material after a data
reconciliation stage with the sender. Here we report the most recent results of
our optical fiber experiment in which we have performed quantum key
distribution over a 48-km optical fiber network at Los Alamos using photon
interference states with the B92 and BB84 quantum key distribution protocols.
| [
{
"version": "v1",
"created": "Thu, 8 Apr 1999 22:20:48 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Hughes",
"Richard J.",
"",
"Los Alamos\n National Laboratory"
],
[
"Morgan",
"George L.",
"",
"Los Alamos\n National Laboratory"
],
[
"Peterson",
"C. Glen",
"",
"Los Alamos\n National Laboratory"
]
] |
quant-ph/9904039 | Yuri I. Ozhigov | Yuri Ozhigov | Speedup of iterated quantum search by parallel performance | Latex, 21 pages, no figures, simplification of the proof | null | null | null | quant-ph | null | Given a sequence $f_1 (x_1), f_2 (x_1, x_2), ..., f_k (x_1, ..., x_k)$ of
Boolean functions, each of which $f_i$ takes the value 1 in a single point of
the form $x_1^0, x_2^0, ..., x_i^0, i=1,2,..., k$. A length of all $x_i^0$ is
$n, N=2^n$. It is shown how to find $x_k^0 (k\geq 2)$ using
\frac{k\pi\sqrt{N}}{4\sqrt{2}}$ simultaneous evaluations of functions of the
form $f_i, f_{i+1}$ with an error probability of order $k/\sqrt{N}$ which is
$\sqrt{2}$ times as fast as by the $k$ sequential applications of Grover
algorithm for the quantum search. Evolutions of amplitudes in parallel quantum
computations are approximated by systems of linear differential equations. Some
advantage of simultaneous evaluations of all $f_1 ,... f_k$ are discussed.
| [
{
"version": "v1",
"created": "Fri, 9 Apr 1999 15:04:24 GMT"
},
{
"version": "v2",
"created": "Mon, 12 Apr 1999 05:12:52 GMT"
},
{
"version": "v3",
"created": "Fri, 16 Apr 1999 11:48:51 GMT"
},
{
"version": "v4",
"created": "Wed, 2 Jun 1999 10:07:07 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ozhigov",
"Yuri",
""
]
] |
quant-ph/9904041 | Alejandro Rivas | A.M.F. Rivas and A.M. Ozorio de Almeida | The Weyl representation on the torus | 26 pages, latex, 4 figures Submitted to Annals of Physics | Annals Phys. 276 (1999) 223-256 | 10.1006/aphy.1999.5942 | EFI-98-34 | quant-ph chao-dyn nlin.CD | null | We construct reflection and translation operators on the Hilbert space
corresponding to the torus by projecting them from the plane. These operators
are shown to have the same group properties as their analogue on the plane. The
decomposition of operators in the basis of reflections corresponds to the Weyl
or center representation, conjugate to the chord representation which is based
on quantized translations. Thus, the symbol of any operator on the torus is
derived as the projection of the symbol on the plane. The group properties
allow us to derive the product law for an arbitrary number of operators in a
simple form. The analogy between the center and the chord representations on
the torus to those on the plane is then exploited to treat Hamiltonian systems
defined on the torus and to formulate a path integral representation of the
evolution operator. We derive its semiclassical approximation.
| [
{
"version": "v1",
"created": "Fri, 9 Apr 1999 21:38:22 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Rivas",
"A. M. F.",
""
],
[
"de Almeida",
"A. M. Ozorio",
""
]
] |
quant-ph/9904042 | Asher Peres | Asher Peres | Delayed choice for entanglement swapping | 7 pages, LaTeX, to appear in special issue of J. Modern Optics | J.Mod.Opt. Vol. 47, Issue 2-3 (2000) 139-143 | 10.1080/09500340008244032 | null | quant-ph | null | Two observers (Alice and Bob) independently prepare two sets of singlets.
They test one particle of each singlet along an arbitrarily chosen direction
and send the other particle to a third observer, Eve. At a later time, Eve
performs joint tests on pairs of particles (one from Alice and one from Bob).
According to Eve's choice of test and to her results, Alice and Bob can sort
into subsets the samples that they have already tested, and they can verify
that each subset behaves as if it consisted of entangled pairs of distant
particles, that have never communicated in the past, even indirectly via other
particles.
| [
{
"version": "v1",
"created": "Sun, 11 Apr 1999 08:32:44 GMT"
}
] | 2015-04-15T00:00:00 | [
[
"Peres",
"Asher",
""
]
] |
quant-ph/9904043 | Brett D. Altschul | Brett D. Altschul | Anomalous Acceleration Effects for Neutrons | 5 pages, RevTeX | null | null | null | quant-ph | null | Comparing the Dirac Hamiltonians for a neutron subjected to either a
Schwartzchild gravitational field or a uniform acceleration, we observe that
the difference between the two is precisely the sort that might be eliminated
by the introduction of a new quantum number. The origin of this quantum number
lies in the noncommutation of an acceleration with the quark operators that
constitute the neutron. We show that the term containing the new quantum number
only acts on very long length scales. Furthermore, the symmetries of an
acceleration prevent the effects of this term from being periodic.
| [
{
"version": "v1",
"created": "Sun, 11 Apr 1999 22:04:06 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Altschul",
"Brett D.",
""
]
] |
quant-ph/9904044 | Yonathan Japha | Y. Japha and G. Kurizki | The Faraday Quantum Clock and Non-local Photon Pair Correlations | 6 figures | null | 10.1103/PhysRevA.60.1811 | null | quant-ph | null | We study the use of the Faraday effect as a quantum clock for measuring
traversal times of evanescent photons through magneto-refractive structures.
The Faraday effect acts both as a phase-shifter and as a filter for circular
polarizations. Only measurements based on the Faraday phase-shift properties
are relevant to the traversal time measurements. The Faraday polarization
filtering may cause the loss of non-local (Einstein-Podolsky-Rosen) two-photon
correlations, but this loss can be avoided without sacrificing the clock
accuracy. We show that a mechanism of destructive interference between
consecutive paths is responsible for superluminal traversal times measured by
the clock.
| [
{
"version": "v1",
"created": "Mon, 12 Apr 1999 09:42:58 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Japha",
"Y.",
""
],
[
"Kurizki",
"G.",
""
]
] |
quant-ph/9904045 | Andrew C. Doherty | A. C. Doherty, A. S. Parkins, S. M. Tan, D. F. Walls | Effects of motion in cavity QED | 10 pages, 5 figures, REVTeX, to be published in Walls Symposium
Special Issue of Journal of Optics B | null | 10.1088/1464-4266/1/4/320 | null | quant-ph | null | We consider effects of motion in cavity quantum electrodynamics experiments
where single cold atoms can now be observed inside the cavity for many Rabi
cycles. We discuss the timescales involved in the problem and the need for good
control of the atomic motion, particularly the heating due to exchange of
excitation between the atom and the cavity, in order to realize nearly unitary
dynamics of the internal atomic states and the cavity mode which is required
for several schemes of current interest such as quantum computing. Using a
simple model we establish ultimate effects of the external atomic degrees of
freedom on the action of quantum gates. The perfomance of the gate is
characterized by a measure based on the entanglement fidelity and the motional
excitation caused by the action of the gate is calculated. We find that schemes
which rely on adiabatic passage, and are not therefore critically dependent on
laser pulse areas, are very much more robust against interaction with the
external degrees of freedom of atoms in the quantum gate.
| [
{
"version": "v1",
"created": "Mon, 12 Apr 1999 13:03:48 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Doherty",
"A. C.",
""
],
[
"Parkins",
"A. S.",
""
],
[
"Tan",
"S. M.",
""
],
[
"Walls",
"D. F.",
""
]
] |
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