id
stringlengths 9
16
| submitter
stringlengths 1
64
⌀ | authors
stringlengths 3
36.7k
| title
stringlengths 1
382
| comments
stringlengths 1
1.15k
⌀ | journal-ref
stringlengths 1
557
⌀ | doi
stringlengths 7
153
⌀ | report-no
stringlengths 1
479
⌀ | categories
stringlengths 5
125
| license
stringclasses 9
values | abstract
stringlengths 6
6.09k
| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9907003 | Noah Linden | Noah Linden, Eriks Kupce, Ray Freeman | NMR Quantum Logic Gates for Homonuclear Spin Systems | 11 pages LaTeX plus 6 figs | null | 10.1016/S0009-2614(99)00829-5 | null | quant-ph | null | If NMR systems are to be used as practical quantum computers, the number of
coupled spins will need to be so large that it is not feasible to rely on
purely heteronuclear spin systems. The implementation of a quantum logic gate
imposes certain constraints on the motion of those spins not directly involved
in that gate, the so-called "spectator" spins; they must be returned to their
initial states at the end of the sequence. As a result, a homonuclear spin
system where there is appreciable coupling between every pair of spins would
seem to require a refocusing scheme that doubles in complexity and duration for
every additional spectator spin. Fortunately, for the more realistic practical
case where long-range spin-spin couplings can be neglected, simpler refocusing
schemes can be devised where the overall duration of the sequence remains
constant and the number of soft pulses increases only linearly with the number
of spectator spins. These ideas are tested experimentally on a six qubit
system: the six coupled protons of inosine.
| [
{
"version": "v1",
"created": "Thu, 1 Jul 1999 15:23:24 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Linden",
"Noah",
""
],
[
"Kupce",
"Eriks",
""
],
[
"Freeman",
"Ray",
""
]
] |
quant-ph/9907004 | Jerry Finkelstein | J. Finkelstein (LBNL and SJSU) | Quantum Probability from Decision Theory? | LaTeX, 5 pages, no figures | null | null | SJSU/TP-99-20 | quant-ph | null | Deutsch has recently (in quant-ph/9906015) offered a justification, based
only on the non-probabilistic axioms of quantum theory and of classical
decision theory, for the use of the standard quantum probability rules. In this
note, this justification is examined.
| [
{
"version": "v1",
"created": "Thu, 1 Jul 1999 18:37:06 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Finkelstein",
"J.",
"",
"LBNL and SJSU"
]
] |
quant-ph/9907005 | Armen G. Grigoryan | A.S.Gevorkyan, A.A.Udalov | Randomly Walking 1D Quantum Harmonic Oscillator. Averaged Transition
Probabilities | LaTeX, SPROCL.STY required, presented on 3rd Int. Workshop "Quantum
Systems: New Trends & Methods" (Minsk, Belarus) | null | null | null | quant-ph | null | One-dimensional problem for quantum harmonic oscillator with "regular+random"
frequency subjected to the external "regular+random" force is considered.
Averaged transition probabilities are found.
| [
{
"version": "v1",
"created": "Thu, 1 Jul 1999 19:40:39 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gevorkyan",
"A. S.",
""
],
[
"Udalov",
"A. A.",
""
]
] |
quant-ph/9907006 | Nicolas Gisin | Andr\'e Stefanov, Nicolas Gisin, Olivier Guinnard, Laurent Guinnard,
Hugo Zbinden | Optical Quantum Random Number Generator | 3 pages + 1 figure | J. Modern Optics, 47, 595-598, 2000 | 10.1080/09500340008233380 | null | quant-ph | null | A physical random number generator based on the intrinsic randomness of
quantum mechanics is described. The random events are realized by the choice of
single photons between the two outputs of a beamsplitter. We present a simple
device, which minimizes the impact of the photon counters' noise, dead-time and
after pulses.
| [
{
"version": "v1",
"created": "Fri, 2 Jul 1999 08:21:02 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Stefanov",
"André",
""
],
[
"Gisin",
"Nicolas",
""
],
[
"Guinnard",
"Olivier",
""
],
[
"Guinnard",
"Laurent",
""
],
[
"Zbinden",
"Hugo",
""
]
] |
quant-ph/9907007 | Richard Jozsa | Graeme Mitchison and Richard Jozsa | Counterfactual Computation | 19 pages. LaTex, 2 figures. Revised version has some new sections and
expanded explanations | Proc.Roy.Soc.Lond. A457 (2001) 1175-1194 | 10.1098/rspa.2000.0714 | null | quant-ph | null | Suppose that we are given a quantum computer programmed ready to perform a
computation if it is switched on. Counterfactual computation is a process by
which the result of the computation may be learnt without actually running the
computer. Such processes are possible within quantum physics and to achieve
this effect, a computer embodying the possibility of running the computation
must be available, even though the computation is, in fact, not run. We study
the possibilities and limitations of general protocols for the counterfactual
computation of decision problems (where the result r is either 0 or 1). If p(r)
denotes the probability of learning the result r ``for free'' in a protocol
then one might hope to design a protocol which simultaneously has large p(0)
and p(1). However we prove that p(0)+p(1) never exceeds 1 in any protocol and
we derive further constraints on p(0) and p(1) in terms of N, the number of
times that the computer is not run. In particular we show that any protocol
with p(0)+p(1)=1-epsilon must have N tending to infinity as epsilon tends to 0.
These general results are illustrated with some explicit protocols for
counterfactual computation. We show that "interaction-free" measurements can be
regarded as counterfactual computations, and our results then imply that N must
be large if the probability of interaction is to be close to zero. Finally, we
consider some ways in which our formulation of counterfactual computation can
be generalised.
| [
{
"version": "v1",
"created": "Fri, 2 Jul 1999 14:52:18 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Oct 2000 15:41:51 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Mitchison",
"Graeme",
""
],
[
"Jozsa",
"Richard",
""
]
] |
quant-ph/9907008 | Fred Cooper | Carl Bender, Fred Cooper, Peter Meisinger and Van M. Savage | Variational Ansatz for PT-Symmetric Quantum Mechanics | 9 pages -- one postscript figure | Phys.Lett. A259 (1999) 224-231 | 10.1016/S0375-9601(99)00468-5 | LA-UR-99-3026 | quant-ph | null | A variational calculation of the energy levels of a class of PT-invariant
quantum mechanical models described by the non-Hermitian Hamiltonian H= p^2 -
(ix)^N with N positive and x complex is presented. Excellent agreement is
obtained for the ground state and low lying excited state energy levels and
wave functions. We use an energy functional with a three parameter class of
PT-symmetric trial wave functions in obtaining our results.
| [
{
"version": "v1",
"created": "Fri, 2 Jul 1999 20:20:04 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Bender",
"Carl",
""
],
[
"Cooper",
"Fred",
""
],
[
"Meisinger",
"Peter",
""
],
[
"Savage",
"Van M.",
""
]
] |
quant-ph/9907009 | Max Tegmark | Max Tegmark | The importance of quantum decoherence in brain processes | Minor changes to match accepted PRE version. 15 pages with 5 figs
included. Color figures and links at
http://www.physics.upenn.edu/~max/brain.html or from [email protected].
Physical Review E, in press | Phys.Rev.E61:4194-4206,2000 | 10.1103/PhysRevE.61.4194 | null | quant-ph cond-mat.dis-nn cs.NE physics.bio-ph q-bio | null | Based on a calculation of neural decoherence rates, we argue that that the
degrees of freedom of the human brain that relate to cognitive processes should
be thought of as a classical rather than quantum system, i.e., that there is
nothing fundamentally wrong with the current classical approach to neural
network simulations. We find that the decoherence timescales ~10^{-13}-10^{-20}
seconds are typically much shorter than the relevant dynamical timescales
(~0.001-0.1 seconds), both for regular neuron firing and for kink-like
polarization excitations in microtubules. This conclusion disagrees with
suggestions by Penrose and others that the brain acts as a quantum computer,
and that quantum coherence is related to consciousness in a fundamental way.
| [
{
"version": "v1",
"created": "Mon, 5 Jul 1999 10:33:19 GMT"
},
{
"version": "v2",
"created": "Wed, 10 Nov 1999 01:45:08 GMT"
}
] | 2009-10-07T00:00:00 | [
[
"Tegmark",
"Max",
""
]
] |
quant-ph/9907010 | Dipankar Home | Somshubhro Bandyopadhyay | Qubit assisted Conclusive Teleportation | 4 pages, Latex, revised version. Title and abstarct changed, some
minor changes in the text | null | null | null | quant-ph | null | We present an optimal method for teleporting an unknown qubit using any pure
entangled state.
| [
{
"version": "v1",
"created": "Sun, 4 Jul 1999 06:09:25 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Jul 1999 08:20:56 GMT"
},
{
"version": "v3",
"created": "Thu, 4 Nov 1999 14:31:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bandyopadhyay",
"Somshubhro",
""
]
] |
quant-ph/9907011 | Miroljub Dugic | Miroljub Dugic (Faculty of Science, Kragujevac, YU) | Quantum mechanical modeling of the CNOT (XOR) gate | A short version. PlainTex, 28 pages, no figures | null | null | null | quant-ph | null | We consider the CNOT quantum gate as a physical action, i.e. as unitary in
time evolution of the two-qubit system. This points to the modeling of the
interaction Hamiltonian of the two-qubit system which would correspond to the
CNOT transformation; the analysis naturally generalizes to the Toffoli gate.
Despite nonuniqueness of the model of the interaction Hamiltonian, the analysis
distinguishes that the interaction Hamiltonian does not posses any global
(rotational) symmetry. This forces us to conclude that the direct
(non-mediated) interaction in the two-qubit system does not suffice for
implementing the CNOT gate. I.e., so as to be able succesfully to implement the
CNOT transformation, a mediator (i.e. an external physical system interacting
with both of the qubits) is required.
| [
{
"version": "v1",
"created": "Sat, 3 Jul 1999 13:09:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Dugic",
"Miroljub",
"",
"Faculty of Science, Kragujevac, YU"
]
] |
quant-ph/9907012 | Richard Shurtleff | Richard Shurtleff | Rotation Representations and e, $pi$, p Masses | 14 pages, 3 figures, Latex | null | null | null | quant-ph hep-ph | null | Mass is proportional to phase gain per unit time; for e, $\pi$, and p the
quantum frequencies are 0.124, 32.6, and 227 Zhz, respectively. By explaining
how these particles acquire phase at different rates, we explain why these
particles have different masses. Any free particle spin 1/2 wave function is a
sum of plane waves with spin parallel to velocity. Each plane wave, a pair of
2-component rotation eigenvectors, can be associated with a 2x2 matrix
representation of rotations in a Euclidean space without disturbing the plane
wave's space-time properties. In a space with more than four dimensions, only
rotations in a 4d subspace can be represented. So far all is well known. Now
consider that unrepresented rotations do not have eigenvectors, do not make
plane waves, and do not contribute phase. The particles e, $\pi,$ and p are
assigned rotations in a 4d subspace of 16d, rotations in an 8d subspace of 12d,
and rotations in a 12d subspace of 12d, respectively. The electron 4d subspace,
assumed to be as likely to align with any one 4d subspace as with any other,
produces phase when aligned with the represented 4d subspace in 16d. Similarly,
we calculate the likelihood that a 4d subspace of the pion's 8d space aligns
with the represented 4d subspace in 12d. The represented 4d subspace is
contained in the proton's 12d space, so the proton always acquires phase. By
the relationship between mass and phase, the resulting particle phase ratios
are the particle mass ratios and these are coincident with the measured mass
ratios, within about one percent. 1999 PACS number(s): 03.65.Fd
Keywords:Algebraic methods; particle masses; rotation group
| [
{
"version": "v1",
"created": "Mon, 5 Jul 1999 12:26:36 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Shurtleff",
"Richard",
""
]
] |
quant-ph/9907013 | Y. Ben-Aryeh | Y. Ben-Aryeh | Heterodyne Detection of Gravitational Waves in a Michelson
Interferometer with a Vibrating Mirror | null | null | null | null | quant-ph | null | A new heterodyne detection method is suggested for detecting gravitational
waves in a Michelson Interferometer. The method is based on interference
between phase changes which are induced by a vibrating mirror with phase
changes which are due to the gravitational waves. The advantage of using a
second order correlation function in the present analysis is discussed.
| [
{
"version": "v1",
"created": "Sun, 4 Jul 1999 14:27:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ben-Aryeh",
"Y.",
""
]
] |
quant-ph/9907014 | Demosthenes Ellinas | Demosthenes Ellinas and Panagiotis Maniadis | q-Symmetries in DNLS-AL chains and exact solutions of quantum dimers | Latex, 19pp, 4 figures. Submitted for publication | Int.J.Mod.Phys. B13 (1999) 3087-3106 | 10.1142/S0217979299002873 | null | quant-ph cond-mat nlin.SI | null | Dynamical symmetries of Hamiltonians quantized models of discrete non-linear
Schroedinger chain (DNLS) and of Ablowitz-Ladik chain (AL) are studied. It is
shown that for $n$-sites the dynamical algebra of DNLS Hamilton operator is
given by the $su(n)$ algebra, while the respective symmetry for the AL case is
the quantum algebra su_q(n). The q-deformation of the dynamical symmetry in the
AL model is due to the non-canonical oscillator-like structure of the raising
and lowering operators at each site.
Invariants of motions are found in terms of Casimir central elements of su(n)
and su_q(n) algebra generators, for the DNLS and QAL cases respectively.
Utilizing the representation theory of the symmetry algebras we specialize to
the $n=2$ quantum dimer case and formulate the eigenvalue problem of each dimer
as a non-linear (q)-spin model. Analytic investigations of the ensuing
three-term non-linear recurrence relations are carried out and the respective
orthonormal and complete eigenvector bases are determined.
The quantum manifestation of the classical self-trapping in the QDNLS-dimer
and its absence in the QAL-dimer, is analysed by studying the asymptotic
attraction and repulsion respectively, of the energy levels versus the strength
of non-linearity. Our treatment predicts for the QDNLS-dimer, a
phase-transition like behaviour in the rate of change of the logarithm of
eigenenergy differences, for values of the non-linearity parameter near the
classical bifurcation point.
| [
{
"version": "v1",
"created": "Mon, 5 Jul 1999 11:22:02 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Ellinas",
"Demosthenes",
""
],
[
"Maniadis",
"Panagiotis",
""
]
] |
quant-ph/9907015 | Svozil Karl | Karl Svozil | "Haunted" quantum contextuality | null | null | null | null | quant-ph | null | Two entangled particles in threedimensional Hilbert space (per particle) are
considered in an EPR-type arrangement. On each side the Kochen-Specker
observables $\{J_1^2,J_2^2,J_3^2\}$ and $\{\bar J_1^2, \bar J_2^2,J_3^2\}$ with
$[J_1^2,\bar J_1^2]\neq 0$ are measured. The outcomes of measurements of
$J_3^2$ (via $J_1^2,J_2^2$) and $J_3^2$ (via $\bar J_1^2,\bar J_2^2$) are
compared. Although formally $J_3^2$ is associated with the same projection
operator, a strong form of quantum contextuality states that an outcome depends
on the complete disposition of the measurement apparatus, in particular whether
$J_1^2$ or $\bar J_1^2$ is measured alongside. It is argued that in this case
it is impossible to measure contextuality directly, a necessary condition being
a non-operational counterfactuality of the argument.
| [
{
"version": "v1",
"created": "Mon, 5 Jul 1999 11:50:24 GMT"
},
{
"version": "v2",
"created": "Wed, 4 Aug 1999 19:15:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Svozil",
"Karl",
""
]
] |
quant-ph/9907016 | Pieter Kok | Pieter Kok, Samuel L. Braunstein | Comment on `Experimental Entanglement Swapping: Entangling Photons That
Never Interacted' | 1 page, REVTeX, 1 figure | null | null | null | quant-ph | null | We comment on the experimental realisation of entanglement swapping by Pan et
al. [Phys. Rev. Lett. 80, 3891 (1998)].
| [
{
"version": "v1",
"created": "Mon, 5 Jul 1999 12:02:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kok",
"Pieter",
""
],
[
"Braunstein",
"Samuel L.",
""
]
] |
quant-ph/9907017 | Afshin Shafiee | A. Shafiee and M. Golshani | Single-particle Bell-type Inequality | 14 pages, 1 figure, Latex file, To appear in Annales de la Fondation
Louis de Broglie | Annales Fond.Broglie 28 (2003) 105 | null | null | quant-ph | null | It is generally believed that Bell's inequality holds for the case of
entangled states, including two correlated particles or special states of a
single particle. Here, we derive a single-particle Bell's inequality for two
correlated spin states at two successive times, appealing to the statistical
independence condition in an ideal experiment, for a locally causal hidden
variables theory. We show that regardless of the locality assumption, the
inequality can be violated by some quantum predictions.
| [
{
"version": "v1",
"created": "Tue, 6 Jul 1999 06:21:30 GMT"
},
{
"version": "v2",
"created": "Sun, 6 Feb 2000 06:34:49 GMT"
},
{
"version": "v3",
"created": "Mon, 18 Mar 2002 06:28:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Shafiee",
"A.",
""
],
[
"Golshani",
"M.",
""
]
] |
quant-ph/9907018 | Holger F. Hofmann | Holger F. Hofmann | Information and noise in quantum measurement | 16 pages, short comment added in II.B., final version for publication
in Phys. Rev. A | Phys.Rev.A62:022103,2000 | 10.1103/PhysRevA.62.022103 | null | quant-ph | null | Even though measurement results obtained in the real world are generally both
noisy and continuous, quantum measurement theory tends to emphasize the ideal
limit of perfect precision and quantized measurement results. In this article,
a more general concept of noisy measurements is applied to investigate the role
of quantum noise in the measurement process. In particular, it is shown that
the effects of quantum noise can be separated from the effects of information
obtained in the measurement. However, quantum noise is required to ``cover up''
negative probabilities arising as the quantum limit is approached. These
negative probabilities represent fundamental quantum mechanical correlations
between the measured variable and the variables affected by quantum noise.
| [
{
"version": "v1",
"created": "Tue, 6 Jul 1999 09:22:52 GMT"
},
{
"version": "v2",
"created": "Tue, 30 Nov 1999 06:15:46 GMT"
},
{
"version": "v3",
"created": "Fri, 18 Feb 2000 05:47:26 GMT"
},
{
"version": "v4",
"created": "Thu, 30 Mar 2000 04:55:06 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Hofmann",
"Holger F.",
""
]
] |
quant-ph/9907019 | Peter Loeber | Peter Loeber | Quantum Channels and Simultaneous ID Coding | 15 pages | null | null | null | quant-ph | null | This paper is on identification of classical information by the use of
quantum channels. We focus on simultaneous ID codes which use measurements
being useful to identify an arbitrary message. We give a direct and a converse
part of the appropriate coding theorem.
| [
{
"version": "v1",
"created": "Tue, 6 Jul 1999 10:02:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Loeber",
"Peter",
""
]
] |
quant-ph/9907020 | Alberto Carlini | A. Carlini and A. Hosoya | Quantum Probabilistic Subroutines and Problems in Number Theory | 9 pages, RevTex, revised version, accepted for publication on PRA:
improvement in use of memory space for quantum primality test algorithm
further clarified and typos in the notation corrected | null | 10.1103/PhysRevA.62.032312 | TIT/HEP-426/COSMO-94 | quant-ph | null | We present a quantum version of the classical probabilistic algorithms
$\grave{a}$ la Rabin. The quantum algorithm is based on the essential use of
Grover's operator for the quantum search of a database and of Shor's Fourier
transform for extracting the periodicity of a function, and their combined use
in the counting algorithm originally introduced by Brassard et al. One of the
main features of our quantum probabilistic algorithm is its full unitarity and
reversibility, which would make its use possible as part of larger and more
complicated networks in quantum computers. As an example of this we describe
polynomial time algorithms for studying some important problems in number
theory, such as the test of the primality of an integer, the so called 'prime
number theorem' and Hardy and Littlewood's conjecture about the asymptotic
number of representations of an even integer as a sum of two primes.
| [
{
"version": "v1",
"created": "Tue, 6 Jul 1999 09:59:54 GMT"
},
{
"version": "v2",
"created": "Mon, 7 Feb 2000 09:21:38 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Carlini",
"A.",
""
],
[
"Hosoya",
"A.",
""
]
] |
quant-ph/9907021 | Jens Eisert | J. Eisert, T. Felbinger, P. Papadopoulos, M. B. Plenio, M. Wilkens | Classical information and distillable entanglement | 5 pages (RevTeX), 1 figure; typos corrected | Phys. Rev. Lett. 84, 1611 (2000) | 10.1103/PhysRevLett.84.1611 | null | quant-ph | null | We establish a quantitative connection between the amount of lost classical
information about a quantum state and the concomitant loss of entanglement.
Using methods that have been developed for the optimal purification of mixed
states we find a class of mixed states with known distillable entanglement.
These results can be used to determine the quantum capacity of a quantum
channel which randomizes the order of transmitted signals.
| [
{
"version": "v1",
"created": "Tue, 6 Jul 1999 16:53:29 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Jul 1999 15:09:49 GMT"
}
] | 2013-09-03T00:00:00 | [
[
"Eisert",
"J.",
""
],
[
"Felbinger",
"T.",
""
],
[
"Papadopoulos",
"P.",
""
],
[
"Plenio",
"M. B.",
""
],
[
"Wilkens",
"M.",
""
]
] |
quant-ph/9907022 | Dr. Arun Kumar Pati | Arun K. Pati | Minimum cbits for remote preperation and measurement of a qubit | Latex, 7 pages, minor changes, references added | Phys.Rev. A63 (2000) 014320 | 10.1103/PhysRevA.63.014302 | null | quant-ph | null | We show that a qubit chosen from equatorial or polar great circles on a Bloch
spehere can be remotely prepared with one cbit from Alice to Bob if they share
one ebit of entanglement. Also we show that any single particle measurement on
an arbitrary qubit can be remotely simulated with one ebit of shared
entanglement and communication of one cbit.
| [
{
"version": "v1",
"created": "Tue, 6 Jul 1999 19:40:52 GMT"
},
{
"version": "v2",
"created": "Tue, 20 Jun 2000 12:02:09 GMT"
},
{
"version": "v3",
"created": "Thu, 27 Jul 2000 11:35:13 GMT"
}
] | 2012-11-20T00:00:00 | [
[
"Pati",
"Arun K.",
""
]
] |
quant-ph/9907023 | A. Perez-Lorenzana | Merced Montesinos and Abdel P\'erez-Lorenzana | Exact solutions of n-level systems and gauge theories | LaTeX file, 5 pages, published version | Phys.Rev. A60 (1999) 2554 | 10.1103/PhysRevA.60.2554 | UMD-PP-00-001 | quant-ph | null | We find a relationship between unitary transformations of the dynamics of
quantum systems with time-dependent Hamiltonians and gauge theories. In
particular, we show that the nonrelativistic dynamics of spin-$\frac12$
particles in a magnetic field $B^i (t)$ can be formulated in a natural way as
an SU(2) gauge theory, with the magnetic field $B^i(t)$ playing the role of the
gauge potential A^i. The present approach can also be applied to systems of n
levels with time-dependent potentials, U(n) being the gauge group. This
geometric interpretation provides a powerful method to find exact solutions of
the Schr\"odinger equation. The root of the present approach rests in the
Hermiticity property of the Hamiltonian operators involved. In addition, the
relationship with true gauge symmetries of n-level quantum systems is
discussed.
| [
{
"version": "v1",
"created": "Tue, 6 Jul 1999 20:13:26 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Sep 1999 19:08:37 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Montesinos",
"Merced",
""
],
[
"Pérez-Lorenzana",
"Abdel",
""
]
] |
quant-ph/9907024 | Jerry Finkelstein | H. Barnum, C. M. Caves, J. Finkelstein, C. A. Fuchs and R. Schack | Quantum Probability from Decision Theory? | LaTeX, 8 pages, no figures | Proc.Roy.Soc.Lond. A456 (2000) 1175-1182 | 10.1098/rspa.2000.0557 | SJSU/TP-99-21 | quant-ph | null | In a recent paper (quant-ph/9906015), Deutsch claims to derive the
"probabilistic predictions of quantum theory" from the "non-probabilistic
axioms of quantum theory" and the "non-probabilistic part of classical decision
theory." We show that his derivation fails because it includes hidden
probabilistic assumptions.
| [
{
"version": "v1",
"created": "Wed, 7 Jul 1999 20:33:47 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Barnum",
"H.",
""
],
[
"Caves",
"C. M.",
""
],
[
"Finkelstein",
"J.",
""
],
[
"Fuchs",
"C. A.",
""
],
[
"Schack",
"R.",
""
]
] |
quant-ph/9907025 | Abel Camacho Quintana | A. Camacho (Astrophysikalisches Institut Potsdam) | Aharonov-Bohm Effect and Coordinate Transformations | 11 pages, 1 figure, accepted in Mod. Phys. Letts. A | Mod.Phys.Lett. A14 (1999) 1445 | 10.1142/S0217732399001541 | null | quant-ph gr-qc | null | Resorting to a Gedankenexperiment which is very similar to the famous
Aharonov-Bohm proposal it will be shown that, in the case of a Minkowskian
spacetime, we may use a nonrelativistic quantum particle and a noninertial
coordinate system and obtain geometric information of regions that are, to this
particle, forbidden. This shows that the outcome of a nonrelativistic quantum
process is determined not only by the features of geometry at those points at
which the process takes place, but also by geometric parameters of regions in
which the quantum system can not enter. From this fact we could claim that
geometry at the quantum level plays a non-local role. Indeed, the measurement
outputs of some nonrelativistic quantum experiments are determined not only by
the geometry of the region in which the experiment takes place, but also by the
geometric properties of spacetime volumes which are, in some way, forbidden in
the experiment.
| [
{
"version": "v1",
"created": "Wed, 7 Jul 1999 21:08:03 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Camacho",
"A.",
"",
"Astrophysikalisches Institut Potsdam"
]
] |
quant-ph/9907026 | Thomas Konrad | J. Audretsch, Th. Konrad, M. Mensky | Approximate real time visualization of a Rabi transition by means of
continuous fuzzy measurement | 17 pages, 6 figures | null | null | null | quant-ph | null | Continuous weak or fuzzy measurement of the Rabi oscillation of a two level
atom subjected to a $\pi-$pulse of a resonant light field is simulated
numerically. We thereby address the question whether it is possible to measure
characteristic features of the motion of the state of a single quantum system
in real time. We compare two schemes of continuous measurement: continuous
measurement with constant fuzziness and with fuzziness changing in the course
of the measurement. Because the sensitivity of the Rabi atom to the influence
of the measurement depends on the state of the atom, it is possible to optimize
the continuous fuzzy measurement by varying its fuzziness.
| [
{
"version": "v1",
"created": "Thu, 8 Jul 1999 08:22:26 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Audretsch",
"J.",
""
],
[
"Konrad",
"Th.",
""
],
[
"Mensky",
"M.",
""
]
] |
quant-ph/9907027 | Tuck Choy | T.C. Choy and Debra Ziegeler | The meaning of 'counterfactual' statements and non-locality in quantum
mechanics | 10 pages, No figures, submitted to American Journal of Physics Apr
1999 | null | null | null | quant-ph physics.hist-ph | null | Recent discussions by Mermin [1] and Stapp [2] in this journal on
non-locality and counterfactuality are shown to contain linguistic problems
that require verification. As such they can at most provide us with two
subjective choices for the meaning of 'counterfactual statements' in quantum
mechanics. We shall show that the word 'counterfactual' is in fact
inappropriate here and should be replaced by the word 'hypothetical'. Mermin's
choice imposes a strictly contextual meaning based upon an interpretation of
counterfactuality which he used to refute, without proof as we shall see,
Stapp's logical proof [3] of non-locality in quantum theory. In linguistic
theory both authors' choices of meaning: counterfactual versus hypothetical are
equally acceptable and therefore some of the issues they discussed lie outside
the domain of physics. The issues they discussed are further confused by the
fact that in his reply Stapp [2] seems to have adopted Mermin's counterfactual
interpretation against his own original [3] hypothetical interpretation. In the
rest of this paper we shall adopt the hypothetical sense of Stapp's original
statements but we modify his crucial statement LOC2 appropriately, then
following his argumentations, we shall show that there is no conflict between
relativity and quantum mechanics. We suggest that this should be the natural
(pragmatic) choice of meaning in defining the predictions of events in the
Hardy experiment.
| [
{
"version": "v1",
"created": "Thu, 8 Jul 1999 11:50:27 GMT"
}
] | 2011-08-08T00:00:00 | [
[
"Choy",
"T. C.",
""
],
[
"Ziegeler",
"Debra",
""
]
] |
quant-ph/9907028 | Guglielmo Tino | G.M. Tino (University of Napoli, Italy) | Testing the symmetrization postulate of quantum mechanics and the
spin-statistics connection | Latex, 14 pages, no figures | Fortsch.Phys.48:537-543,2000 | 10.1002/(SICI)1521-3978(200005)48:5/7<537::AID-PROP537>3.0.CO;2-C | DSF-23-99 | quant-ph | null | Recent experimental tests of the symmetrization postulate of quantum
mechanics are discussed. It is shown that in a strict sense these experiments
cannot test the validity of the symmetrization postulate, but in most cases do
test the spin-statistics connection. An experiment is proposed that would allow
to search for possible violations of the symmetrization postulate.
| [
{
"version": "v1",
"created": "Thu, 8 Jul 1999 13:05:06 GMT"
}
] | 2017-04-26T00:00:00 | [
[
"Tino",
"G. M.",
"",
"University of Napoli, Italy"
]
] |
quant-ph/9907029 | Dipankar Home | Somshubhro Bandyopadhyay and Dipankar Home | Barrier Perturbation Induced Superarrivals and Nonlocality in a
Time-Evolving Wave Packet | latex, 6 figures | null | null | null | quant-ph | null | We compute the time evolving probability of a Gaussian wave packet to be
reflected from a rectangular potential barrier which is perturbed by reducing
its height. A time interval is found during which this probability of
reflection is enhanced (superarrivals) compared to the unperturbed case. Such a
time evolving reflection probability implies that the effect of perturbation
propagates across the wave packet faster than its group velocity - a curious
form of nonlocality.
| [
{
"version": "v1",
"created": "Thu, 8 Jul 1999 13:16:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bandyopadhyay",
"Somshubhro",
""
],
[
"Home",
"Dipankar",
""
]
] |
quant-ph/9907030 | Dipankar Home | Sayandeb Basu, Somshubhro Bandyopadhyay, Guruprasad Kar and Dipankar
Home | Bell's inequality for a single spin 1/2 particle and quantum
contextuality | Latex, 7 pages, 2 Figs. published version with a note added to the
proof | Phys. Lett. A Vol. 279 issue 5-6 pp. 281-286 | 10.1016/S0375-9601(00)00747-7 | null | quant-ph | null | We argue that for a \emph{single particle} Bell's inequality is a consequence
of noncontextuality and is \emph{incompatible} with statistical predictions of
quantum mechanics. Thus noncontextual models can be empirically falsified,
\emph{independent} of locality condition. For this an appropriate entanglement
between \emph{disjoint} Hilbert spaces pertaining to translational and spin
degrees of freedom of a single spin-1/2 particle is invoked
| [
{
"version": "v1",
"created": "Thu, 8 Jul 1999 13:59:18 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Apr 2000 04:46:34 GMT"
},
{
"version": "v3",
"created": "Sun, 18 Mar 2001 07:51:53 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Basu",
"Sayandeb",
""
],
[
"Bandyopadhyay",
"Somshubhro",
""
],
[
"Kar",
"Guruprasad",
""
],
[
"Home",
"Dipankar",
""
]
] |
quant-ph/9907031 | Habatwa Vincent Mweene | Habatwa Vincent Mweene (Physics Department, University of Zambia) | Alternative Forms of Generalized Vectors and Operators for Spin 1/2 | LaTeX, 14 pages.Replaced after thorough revision of notation and
improvement to some sections | null | null | UNZAPHYS-004 | quant-ph | null | The forms of the generalized quantities that we have recently introduced are
dependent on the phase of the probability amplitudes for spin-projection
measurements. In this paper, we show explicitly that changing the phase gives
different forms for both the spin vectors and spin operators. Therefore, there
are as many forms of these quantities as there are different choices of phase.
| [
{
"version": "v1",
"created": "Thu, 8 Jul 1999 17:23:18 GMT"
},
{
"version": "v2",
"created": "Sat, 1 Jul 2000 00:28:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mweene",
"Habatwa Vincent",
"",
"Physics Department, University of Zambia"
]
] |
quant-ph/9907032 | Michael Fleischhauer | M. Fleischhauer, M. D. Lukin, A. B. Matsko, and M. O. Scully | Threshold and linewidth of a mirrorless parametric oscillator | revised version to appear in Phys.Rev.Lett., contains discussion on
threshold conditions and operation on few-photon level | null | 10.1103/PhysRevLett.84.3558 | null | quant-ph | null | We analyze the above-threshold behavior of a mirrorless parametric oscillator
based on resonantly enhanced four wave mixing in a coherently driven dense
atomic vapor. It is shown that, in the ideal limit, an arbitrary small flux of
pump photons is sufficient to reach the oscillator threshold. We demonstrate
that due to the large group-velocity delays associated with coherent media, an
extremely narrow oscillator linewidth is possible, making a narrow-band source
of non-classical radiation feasible.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 08:09:12 GMT"
},
{
"version": "v2",
"created": "Wed, 9 Feb 2000 08:36:15 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Fleischhauer",
"M.",
""
],
[
"Lukin",
"M. D.",
""
],
[
"Matsko",
"A. B.",
""
],
[
"Scully",
"M. O.",
""
]
] |
quant-ph/9907033 | Habatwa Vincent Mweene | Habatwa Vincent Mweene (Physics Department, University of Zambia) | Spin Description and Calculation in the Lande' Interpretation of Quantum
Mechanics | LaTeX, 15 pages.Replaced after thorough revision of notation and
improvement to some sections | null | null | UNZAPHYS-005 | quant-ph | null | We explain the connection between the generalized spin quantities we have
recently introduced and standard forms. We show how the calculation of various
quantities of interest using these new forms is done. Focusing attention on
expectation values, we find that in every case, the standard results can be
obtained as special cases arising from the new generalized results.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 10:33:50 GMT"
},
{
"version": "v2",
"created": "Sat, 1 Jul 2000 00:04:50 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mweene",
"Habatwa Vincent",
"",
"Physics Department, University of Zambia"
]
] |
quant-ph/9907034 | A. Heidmann | A. Heidmann, P.F. Cohadon, M. Pinard | Thermal noise of a plano-convex mirror | 5 pages, 5 figures, RevTeX | Phys.Lett. A263 (1999) 27-32 | 10.1016/S0375-9601(99)00704-5 | null | quant-ph | null | We study theoretically the internal thermal noise of a mirror coated on a
plano-convex substrate. The comparison with a cylindrical mirror of the same
mass shows that the effect on a light beam can be reduced by a factor 10,
improving the sensitivity of high-precision optical experiments such as
gravitational-wave interferometers.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 13:10:16 GMT"
},
{
"version": "v2",
"created": "Wed, 23 Feb 2000 17:21:58 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Heidmann",
"A.",
""
],
[
"Cohadon",
"P. F.",
""
],
[
"Pinard",
"M.",
""
]
] |
quant-ph/9907035 | Paul Vitanyi | Paul Vitanyi (CWI & University of Amsterdam) | Three Approaches to the Quantitative Definition of Information in an
Individual Pure Quantum State | 8 pages, LaTeX | In: Proc. 15th IEEE Conf. Computational Complexity, 2000 | null | null | quant-ph | null | In analogy of classical Kolmogorov complexity we develop a theory of the
algorithmic information in bits contained in any one of continuously many pure
quantum states: quantum Kolmogorov complexity. Classical Kolmogorov complexity
coincides with the new quantum Kolmogorov complexity restricted to the
classical domain. Quantum Kolmogorov complexity is upper bounded and can be
effectively approximated from above. With high probability a quantum object is
incompressible. There are two alternative approaches possible: to define the
complexity as the length of the shortest qubit program that effectively
describes the object, and to use classical descriptions with computable real
parameters.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 14:02:18 GMT"
},
{
"version": "v2",
"created": "Thu, 22 Jul 1999 16:04:08 GMT"
},
{
"version": "v3",
"created": "Thu, 4 May 2000 16:27:41 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Vitanyi",
"Paul",
"",
"CWI & University of Amsterdam"
]
] |
quant-ph/9907036 | Daniel R. Terno | Tal Mor and Daniel R. Terno | Sufficient conditions for a disentanglement | 3 pages, REVTEX, no figures | Phys.Rev.A60:4341,1999 | 10.1103/PhysRevA.60.4341 | null | quant-ph | null | We consider a disentanglement process in which local properties of an
entangled state are preserved, while the entanglement between the subsystems is
erased. Sufficient conditions for a perfect disentanglement (into product
states and into separable states) are derived, and connections to the
conditions for perfect cloning and for perfect broadcasting are observed.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 16:19:31 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Mor",
"Tal",
""
],
[
"Terno",
"Daniel R.",
""
]
] |
quant-ph/9907037 | Yeranuhi Hakobyan | E. G. Kalnins, W. Miller Jr, Ye. M. Hakobyan, G. S. Pogosyan | Superintegrability on the two dimensional hyperboloid II | 18 pages, LaTex; 1 figure (eps) | J.Math.Phys. 40 (1999) 2291-2306 | 10.1063/1.532864 | Preprint JINR E2-98-229 | quant-ph hep-th math-ph math.MP | null | This work is devoted to the investigation of the quantum mechanical systems
on the two dimensional hyperboloid which admit separation of variables in at
least two coordinate systems. Here we consider two potentials introduced in a
paper of C.P.Boyer, E.G.Kalnins and P.Winternitz, which haven't yet been
studied. We give an example of an interbasis expansion and work out the
structure of the quadratic algebra generated by the integrals of motion.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 19:51:17 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Kalnins",
"E. G.",
""
],
[
"Miller",
"W.",
"Jr"
],
[
"Hakobyan",
"Ye. M.",
""
],
[
"Pogosyan",
"G. S.",
""
]
] |
quant-ph/9907038 | Mladen Pavicic | Mladen Pavicic | Event-ready entanglement preparation | 10 pages, LaTeX, 4 figures, Author's URL http://m3k.grad.hr/pavicic | in "Quantum Interferometry," Proceedings of the Adriatico
Workshop, Trieste, March 1996. F. De Martini, G. Denardo, and Y. Shih (eds.),
(VCH, New York, 1996), pp. 193-204 | null | null | quant-ph | null | We present an experiment which prepare entanglement between photons that
nowhere interacted and whose paths nowhere crossed. The experiment puts
together two photons from two (non-maximal) singlet-like photon pairs and make
them interfere at an asymmetrical beam splitter. As a result one finds
polarization correlations between the other companion photons from the pairs
whose paths nowhere crossed each other even when no polarization measurements
have been carried out on the former photons. The latter set of photons that
nowhere interacted are therefore event-ready prepared by their pair-companion
photons. The result reveals nonlocality as a property of selection which can
even be a preselection. It also reveals that one can predict spin-correlated
behaviour of photons in space and at beam splitters by controlling a no-spin
observable. [From the Book of Abstracts as appeared at the Workshop.]
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 21:06:48 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Pavicic",
"Mladen",
""
]
] |
quant-ph/9907039 | Mladen Pavicic | Mladen Pavicic | A method for reaching detection efficiencies necessary for optical
loophole-free Bell experiments | RevTeX, 20 pages, 2figures, Author's URL http://m3k.grad.hr/pavicic | Opt.Commun. 142 (1997) 308-314 | 10.1016/S0030-4018(97)00285-X | null | quant-ph | null | A method for preparing a loophole-free four-photon Bell experiments which
requires a detection efficiency of 67% is proposed. It enables realistic
detection efficiencies of 75% at a visibility of 85%. Two type-II crystals each
down convert one correlated photon pair and we entangle one photon from one
pair with one photon from the other pair on a highly transparent beam splitter.
The entanglement selects two other conjugate photons into a Bell state. Wide
solid angles for the conjugate photons then enable us to collect close to 100%
of them. The cases when both photon pairs come from only one of the two
crystals are successfully taken into account. Hardy's equalities are discussed.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 22:22:45 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Pavicic",
"Mladen",
""
]
] |
quant-ph/9907040 | Mladen Pavicic | Mladen Pavicic | Resonance energy-exchange-free detection and "welcher Weg" experiment | RevTeX, 14 pages, 3 figures, see http://m3k.grad.hr/pavicic for
Author's web site | Phys.Lett. A223 (1996) 241-245 | 10.1016/S0375-9601(96)00751-7 | null | quant-ph | null | It is shown that a monolithic total-internal-reflection resonator can be used
for energy-exchange-free detections of objects without recoils. Related
energy-exchange-free detection of "welcher Weg" is discussed and an experiment
with an atom interferometer is proposed. The obtained results are in agreement
with quantum theory.
| [
{
"version": "v1",
"created": "Fri, 9 Jul 1999 23:31:00 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Pavicic",
"Mladen",
""
]
] |
quant-ph/9907041 | Jinhyoung Lee | Jinhyoung Lee and M. S. Kim | Entanglement Teleportation via Werner States | 4pages, 3figures | Phys.Rev.Lett.84:4236,2000 | 10.1103/PhysRevLett.84.4236 | null | quant-ph | null | Transfer of entanglement and information is studied for quantum teleportation
of an unknown entangled state through noisy quantum channels. We find that the
quantum entanglement of the unknown state can be lost during the teleportation
even when the channel is quantum correlated. We introduce a fundamental
parameter of correlation information which dissipates linearly during the
teleportation through the noisy channel. Analyzing the transfer of correlation
information, we show that the purity of the initial state is important in
determining the entanglement of the replica state.
| [
{
"version": "v1",
"created": "Sat, 10 Jul 1999 06:33:41 GMT"
},
{
"version": "v2",
"created": "Fri, 25 Feb 2000 09:02:55 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Lee",
"Jinhyoung",
""
],
[
"Kim",
"M. S.",
""
]
] |
quant-ph/9907042 | Dominik Janzing | Dominik Janzing and Thomas Beth | Fragility of a class of highly entangled states of many quantum-bits | 9 Pages, RevTex | Phys.Rev.A61:052308,2000 | 10.1103/PhysRevA.61.052308 | null | quant-ph | null | We consider a Quantum Computer with n quantum-bits (`qubits'), where each
qubit is coupled independently to an environment affecting the state in a
dephasing or depolarizing way. For mixed states we suggest a quantification for
the property of showing {\it quantum} uncertainty on the macroscopic level. We
illustrate in which sense a large parameter can be seen as an indicator for
large entanglement and give hypersurfaces enclosing the set of separable
states. Using methods of the classical theory of maximum likelihood estimation
we prove that this parameter is decreasing with 1/\sqrt{n} for all those states
which have been exposed to the environment.
Furthermore we consider a Quantum Computer with perfect 1-qubit gates and
2-qubit gates with depolarizing error and show that any state which can be
obtained from a separable initial state lies inbetween a family of pairs of
certain hypersurfaces parallel to those enclosing the separable ones.
| [
{
"version": "v1",
"created": "Sat, 10 Jul 1999 13:04:40 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Janzing",
"Dominik",
""
],
[
"Beth",
"Thomas",
""
]
] |
quant-ph/9907043 | Radu Ionicioiu | Radu Ionicioiu, Gehan Amaratunga, Florin Udrea (University of
Cambridge, UK) | Ballistic Single-Electron Quputer | 5 pages, LaTeX, 3 figures, uses epsf | null | null | null | quant-ph cond-mat | null | We propose a new solid state implementation of a quantum computer (quputer)
using ballistic single electrons as flying qubits in 1D nanowires. We use a
single electron pump (SEP) to prepare the initial state and a single electron
transistor (SET) to measure the final state. Single qubit gates are implemented
using quantum dots as phase shifters and electron waveguide couplers as beam
splitters. A Coulomb coupler acts as a 2-qubit gate, using a mutual phase
modulation effect. Since the electron phase coherence length in GaAs/AlGaAs
heterostructures is of the order of 30$\mu$m, several gates (tens) can be
implemented before the system decoheres.
| [
{
"version": "v1",
"created": "Sun, 11 Jul 1999 00:25:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ionicioiu",
"Radu",
"",
"University of\n Cambridge, UK"
],
[
"Amaratunga",
"Gehan",
"",
"University of\n Cambridge, UK"
],
[
"Udrea",
"Florin",
"",
"University of\n Cambridge, UK"
]
] |
quant-ph/9907044 | Gov Shahar | S. Gov (1), S. Shtrikman (1+2), H. Thomas (3) ((1) The Dept. of
Electronics, Weizmann Institute of Science, Rehovot, Israel (2) The Dept. of
Physics, University of California, San Diego, CA, USA (3) The Department of
Physics and Astronomy, University of Basel, Basel, Switzerland) | Magnetic trapping of neutral particles: Classical and Quantum-mechanical
study of a Ioffe-Pritchard type trap | 25 pages + 1 EPS figure | null | 10.1063/1.372444 | null | quant-ph | null | Recently, we developed a method for calculating the lifetime of a particle
inside a magnetic trap with respect to spin flips, as a first step in our
efforts to understand the quantum-mechanics of magnetic traps. The 1D toy model
that was used in this study was physically unrealistic because the magnetic
field was not curl-free. Here, we study, both classically and
quantum-mechanically, the problem of a neutral particle with spin S, mass m and
magnetic moment mu, moving in 3D in an inhomogeneous magnetic field
corresponding to traps of the Ioffe-Pritchard, `clover-leaf' and `baseball'
type. Defining by omega_p, omega_z and omega_r the precessional, the axial and
the lateral vibrational frequencies, respectively, of the particle in the
adiabatic potential, we find classically the region in the $(\omega_{r}%
(omega_r -- omega_z) plane where the particle is trapped.
Quantum-mechanically, we study the problem of a spin-one particle in the same
field. Treating omega_r / omega_p and omega_z / omega_p as small parameters for
the perturbation from the adiabatic Hamiltonian, we derive a closed-form
expression for the transition rate 1/T_{esc} of the particle from its trapped
ground-state. We find that in the extreme cases, the expression for 1/T_{esc}
is dominated by the largest of the two frequencies omega_r and omega_z.
| [
{
"version": "v1",
"created": "Mon, 12 Jul 1999 06:47:56 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Gov",
"S.",
"",
"1+2"
],
[
"Shtrikman",
"S.",
"",
"1+2"
],
[
"Thomas",
"H.",
""
]
] |
quant-ph/9907045 | Krutitsky | K.V.Krutitsky, F.Burgbacher and J.Audretsch | Microscopic theory of the interaction of ultracold dense Bose and Fermi
gases with electromagnetic field | 6 pages, RevTeX, invited talk at the 8TH International Workshop on
Laser Physics | Laser Physics 10(1), 15-20 (2000) | null | null | quant-ph | null | We present the rigorous microscopic quantum theory of the interaction of
ultracold Bose and Fermi gases with the electromagnetic field of vacuum and
laser photons. The main attention has been paid to the consistent consideration
of dynamical dipole-dipole interactions. The theory developed is shown to be
consistent with the general principles of the canonical quantization of
electromagnetic field in a medium. Starting from the first principles of QED we
have derived the general system of Maxwell-Bloch equations for atomic creation
and annihilation operators and the propagation equation for the laser field
which can be used for the self-consistent analysis of various linear and
nonlinear phenomena in atom optics at high densities of the atomic system. All
known equations which are used for the description of the behaviour of an
ultracold atomic ensemble in a radiation field can be obtained from our general
system of equations in a low-density limit.
| [
{
"version": "v1",
"created": "Mon, 12 Jul 1999 07:48:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Krutitsky",
"K. V.",
""
],
[
"Burgbacher",
"F.",
""
],
[
"Audretsch",
"J.",
""
]
] |
quant-ph/9907046 | Antonio Vidiella-Barranco | H. Moya-Cessa, S.M. Dutra, A. Vidiella-Barranco and J.A. Roversi
(Universidade Estadual de Campinas, Brazil) | Quantum state reconstruction in the presence of dissipation | null | J.Mod.Opt. 46 (1999) 555 | 10.1080/09500349908231283 | null | quant-ph | null | We propose a realistic scheme to determine the quantum state of a single mode
cavity field even after it has started to decay due to the coupling with an
environment. Although dissipation destroys quantum coherences, we show that at
zero temperature enough information about the initial state remains, in an
observable quantity, to allow the reconstruction of its Wigner function.
| [
{
"version": "v1",
"created": "Mon, 12 Jul 1999 17:45:36 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Moya-Cessa",
"H.",
"",
"Universidade Estadual de Campinas, Brazil"
],
[
"Dutra",
"S. M.",
"",
"Universidade Estadual de Campinas, Brazil"
],
[
"Vidiella-Barranco",
"A.",
"",
"Universidade Estadual de Campinas, Brazil"
],
[
"Roversi",
"J. A.",
"",
"Universidade Estadual de Campinas, Brazil"
]
] |
quant-ph/9907047 | William K. Wootters | Valerie Coffman, Joydip Kundu, and William K. Wootters | Distributed Entanglement | 13 pages LaTeX; references added, derivation of Eq. (11) simplified | Phys.Rev.A61:052306,2000 | 10.1103/PhysRevA.61.052306 | null | quant-ph | null | Consider three qubits A, B, and C which may be entangled with each other. We
show that there is a trade-off between A's entanglement with B and its
entanglement with C. This relation is expressed in terms of a measure of
entanglement called the "tangle," which is related to the entanglement of
formation. Specifically, we show that the tangle between A and B, plus the
tangle between A and C, cannot be greater than the tangle between A and the
pair BC. This inequality is as strong as it could be, in the sense that for any
values of the tangles satisfying the corresponding equality, one can find a
quantum state consistent with those values. Further exploration of this result
leads to a definition of the "three-way tangle" of the system, which is
invariant under permutations of the qubits.
| [
{
"version": "v1",
"created": "Tue, 13 Jul 1999 07:38:38 GMT"
},
{
"version": "v2",
"created": "Sat, 24 Jul 1999 07:01:01 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Coffman",
"Valerie",
""
],
[
"Kundu",
"Joydip",
""
],
[
"Wootters",
"William K.",
""
]
] |
quant-ph/9907048 | Tomas Opatrny | T. Opatrny, G. Kurizki, and D.-G. Welsch | Continuous-variable teleportation improvement by photon subtraction via
conditional measurement | 7 pages REVTeX, 7 figures | Phys.Rev. A61 (2000) 032302 | 10.1103/PhysRevA.61.032302 | null | quant-ph | null | We show that the recently proposed scheme of teleportation of continuous
variables [S.L. Braunstein and H.J. Kimble, Phys. Rev. Lett. 80, 869 (1998)]
can be improved by a conditional measurement in the preparation of the
entangled state shared by the sender and the recipient. The conditional
measurement subtracts photons from the original entangled two-mode squeezed
vacuum, by transmitting each mode through a low-reflectivity beam splitter and
performing a joint photon-number measurement on the reflected beams. In this
way the degree of entanglement of the shared state is increased and so is the
fidelity of the teleported state.
| [
{
"version": "v1",
"created": "Tue, 13 Jul 1999 13:28:28 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Opatrny",
"T.",
""
],
[
"Kurizki",
"G.",
""
],
[
"Welsch",
"D. -G.",
""
]
] |
quant-ph/9907049 | Andrew Scott Parkins | A.S. Parkins, H.J. Kimble | A position-momentum EPR state of distantly-separated trapped atoms | 5 pages, 2 figures, submitted to Phys. Rev. A | null | 10.1103/PhysRevA.61.052104 | null | quant-ph | null | We propose a scheme for preparing an EPR state in position and momentum of a
pair of distantly-separated trapped atoms. The scheme utilizes the entangled
light fields output from a nondegenerate optical parametric amplifier. Quantum
state exchange between these fields and the motional states of the trapped
atoms is accomplished via interactions in cavity QED.
| [
{
"version": "v1",
"created": "Tue, 13 Jul 1999 22:07:36 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Parkins",
"A. S.",
""
],
[
"Kimble",
"H. J.",
""
]
] |
quant-ph/9907050 | Ghirardi Giancarlo, | Angelo Bassi, GianCarlo Ghirardi | More about Dynamical Reduction and the Enumeration Principle | 23 pages, Latex, to appear in Brit. J. Phil. Sci | Brit. Journ. Phil. Sci. 50, 719 (1999). | null | null | quant-ph | null | In view of the arguments put forward by Clifton and Monton [1999] in a recent
preprint, we reconsider the alleged conflict of dynamical reduction models with
the enumeration principle. We prove that our original analysis of such a
problem is correct, that the GRW model does not meet any difficulty and that
the reasoning of the above authors is inappropriate since it does not take into
account the correct interpretation of the dynamical reduction theories.
| [
{
"version": "v1",
"created": "Wed, 14 Jul 1999 15:13:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bassi",
"Angelo",
""
],
[
"Ghirardi",
"GianCarlo",
""
]
] |
quant-ph/9907051 | null | B. Carazza (Dipartimento di Fisica, Parma, Italy) | Decoherence within a simple Model for the Environment | 13 pages, LaTex, no figures. To appear on Found. Phys. Letts | Found.Phys.Lett. 12 (1999) 485-495 | null | null | quant-ph | null | This article examines the decoherence of a macroscopic body using a simple
model of the environment and following the evolution of the pure state for the
whole system. We found that decoherence occurs for very general initial
conditions and were able to confirm a number of widely accepted features of the
process.
| [
{
"version": "v1",
"created": "Wed, 14 Jul 1999 16:27:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Carazza",
"B.",
"",
"Dipartimento di Fisica, Parma, Italy"
]
] |
quant-ph/9907052 | A. M. Lisewski | A.M. Lisewski | Can all neurobiological processes be described by classical physics? | null | null | null | null | quant-ph | null | We discuss results recently given in an article by M. Tegmark
(quant-ph/9907009) where he argues that neurons can be described appropriately
by pure classical physics. This letter is dedicated to the question if this is
really the case when the role of dissipation and noise -- the two concurrent
phenomena present in these biological structures -- is taken into account. We
argue that dissipation and noise might well be of quantum origin and give also
a possible reason why neural dynamics is not classical.
| [
{
"version": "v1",
"created": "Thu, 15 Jul 1999 08:42:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lisewski",
"A. M.",
""
]
] |
quant-ph/9907053 | Thorsten Koehler | R. E. Grisenti, W. Schoellkopf, J. P. Toennies, G. C. Hegerfeldt, and
T. Koehler | Determination of Atom-Surface van der Waals Potentials from
Transmission-Grating Diffraction Intensities | 4 pages Revtex + 3 figures. Physical Review Letters (in press) | Phys.Rev.Lett. 83 (1999) 1755-1758 | 10.1103/PhysRevLett.83.1755 | null | quant-ph | null | Molecular beams of rare gas atoms and D_2 have been diffracted from
100 nm period SiN_x transmission gratings. The relative intensities of the
diffraction peaks out to the 8th order depend on the diffracting particle and
are interpreted in terms of effective slit widths. These differences have been
analyzed by a new theory which accounts for the long-range van der Waals
-C_3/l^3 interaction of the particles with the walls of the grating bars. The
values of the C_3 constant for two different gratings are in good agreement and
the results exhibit the expected linear dependence on the dipole
polarizability.
| [
{
"version": "v1",
"created": "Thu, 15 Jul 1999 12:19:22 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Grisenti",
"R. E.",
""
],
[
"Schoellkopf",
"W.",
""
],
[
"Toennies",
"J. P.",
""
],
[
"Hegerfeldt",
"G. C.",
""
],
[
"Koehler",
"T.",
""
]
] |
quant-ph/9907054 | Miloslav Znojil | Miloslav Znojil | Bound states in the Kratzer plus polynomial potentials and their new
exact tractability via nonlinear algebraic equations | 24 pages incl. 4 tables, submitted to J. Math. Chem | J.Math.Chem. 26 (1999) 157-172 | null | null | quant-ph | null | Schroedinger equation with potentials of the Kratzer plus polynomial type
(say, quartic V(r) = A r^4 +B r^3 + C r^2+D r + F/r + G/r^2 etc) is considered.
A new method of exact construction of some of its bound states is then
proposed. it is based on the Taylor series terminated rigorously after N+1
terms at specific couplings and energies. This enables us to find the exact,
complete and compact unperturbed solution of the Magyari's N+2 coupled and
nonlinear algebraic conditions of the termination in the strong-coupling regime
with G \to \infty. Next, at G < \infty, we adapt the Rayleigh-Schroedinger
perturbation theory and define the bound states via an innovated, triple
perturbation series. In tests we show that all the correction terms appear in
integer arithmetics and remain, therefore, exact.
| [
{
"version": "v1",
"created": "Thu, 15 Jul 1999 13:08:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Znojil",
"Miloslav",
""
]
] |
quant-ph/9907055 | Michael G. Moore | G.A. Prataviera, E. V. Goldstein, and P. Meystre | Mutual coherence of optical and matter waves | null | null | 10.1103/PhysRevA.60.4846 | null | quant-ph | null | We propose a scheme to measure the cross-correlations and mutual coherence of
optical and matter fields. It relies on the combination of a matter-wave
detector operating by photoionization of the atoms and a traditional absorption
photodetector. We show that the double-detection signal is sensitive to
cross-correlation functions of light and matter waves.
| [
{
"version": "v1",
"created": "Thu, 15 Jul 1999 20:24:51 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Prataviera",
"G. A.",
""
],
[
"Goldstein",
"E. V.",
""
],
[
"Meystre",
"P.",
""
]
] |
quant-ph/9907056 | Howard N. Barnum | Howard Barnum, Herbert J. Bernstein, Lee Spector | A quantum circuit for OR | 4 pages + 2 postscript figures. Version 3 restores the figures to
Version 2, which changed the title, abstract, introduction and concluding
paragraph, order of material, and emphasis from Version 1. No change in
technical content | null | null | null | quant-ph | null | We give the first quantum circuit for computing $f(0)$ OR $f(1)$ more
reliably than is classically possible with a single evaluation of the function.
OR therefore joins XOR (i.e. parity, $f(0) \oplus f(1)$) to give the full set
of logical connectives (up to relabeling of inputs and outputs) for which there
is quantum speedup. The XOR algorithm is of fundamental importance in quantum
computation; our OR algorithm (found with the aid of genetic programming), may
represent a new quantum computational effect, also useful as a ``subroutine''.
| [
{
"version": "v1",
"created": "Fri, 16 Jul 1999 15:00:38 GMT"
},
{
"version": "v2",
"created": "Thu, 30 Sep 1999 21:02:54 GMT"
},
{
"version": "v3",
"created": "Fri, 8 Oct 1999 16:26:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Barnum",
"Howard",
""
],
[
"Bernstein",
"Herbert J.",
""
],
[
"Spector",
"Lee",
""
]
] |
quant-ph/9907057 | Massimiliano F. Sacchi | G. M. D'Ariano, M. F. Sacchi, H. P. Yuen | On the correspondence between classical and quantum measurements on a
bosonic field | RevTex. 17 pages. 1 eps figure. To appear on Mod. Phys. Lett. B | Int.J.Mod.Phys. B13 (1999) 3069-3086 | 10.1142/S0217979299002861 | null | quant-ph | null | We study the correspondence between classical and quantum measurements on a
harmonic oscillator that describes a one-mode bosonic field. We connect the
quantum measurement of an observable of the field with the possibility of
amplifying the observable ideally through a quantum amplifier. The
``classical'' measurement corresponds to the joint measurement of the position
$q$ and momentum $p$ of the harmonic oscillator, with following evaluation of a
function $f$ of the outcome $\alpha=q+ip$. For the electromagnetic field the
joint measurement is achieved by a heterodyne detector. The quantum measurement
of an observable $\hat O$ is obtained by preamplifying the heterodyne detector
through an ideal amplifier of $\hat O$, and rescaling the outcome by the gain
$g$. We give a general criterion which states when this preamplified heterodyne
detection scheme approaches the ideal quantum measurement of $\hat O$ in the
limit of infinite gain. We show that this criterion is satisfied and the ideal
measurement is achieved for the case of the photon number operator and for the
quadrature. For both operators the method is robust to nonunit quantum
efficiency of the heterodyne detector. On the other hand, we show that the
preamplified heterodyne detection scheme does not work for arbitrary observable
of the field. As a counterexample, we prove that the simple quadratic function
of the field $\hat K=i(a^{\dag 2}-a^2)/2$ has no corresponding polynomial
function $f(\alpha,\bar \alpha)$---including the obvious choice
$f=\hbox{Im}(\alpha^2)$---that allows the measurement of $\hat K$ through the
preamplified heterodyne measurement scheme.
| [
{
"version": "v1",
"created": "Fri, 16 Jul 1999 16:06:31 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"D'Ariano",
"G. M.",
""
],
[
"Sacchi",
"M. F.",
""
],
[
"Yuen",
"H. P.",
""
]
] |
quant-ph/9907058 | C. Y. Chen | C.Y.Chen | Transition probability and preferential gauge | 7 pages, O figure | null | null | null | quant-ph | null | This paper is concerned with whether or not the preferential gauge can ensure
the uniqueness and correctness of results obtained from the standard
time-dependent perturbation theory, in which the transition probability is
formulated in terms of matrix elements of Hamiltonian.
| [
{
"version": "v1",
"created": "Sat, 17 Jul 1999 02:22:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chen",
"C. Y.",
""
]
] |
quant-ph/9907059 | M. Czachor | Marek Czachor, Heinz-Dietrich Doebner, Monika Syty, and Krzysztof
Wasylka | Von Neumann equations with time-dependent Hamiltonians and
supersymmetric quantum mechanics | revtex, 3 eps files | Phys.Rev.E61:3325-3329,2000 | 10.1103/PhysRevE.61.3325 | null | quant-ph | null | Starting with a time-independent Hamiltonian $h$ and an appropriately chosen
solution of the von Neumann equation $i\dot\rho(t)=[ h,\rho(t)]$ we construct
its binary-Darboux partner $h_1(t)$ and an exact scattering solution of
$i\dot\rho_1(t)=[h_1(t),\rho_1(t)]$ where $h_1(t)$ is time-dependent and not
isospectral to $h$. The method is analogous to supersymmetric quantum mechanics
but is based on a different version of a Darboux transformation. We illustrate
the technique by the example where $h$ corresponds to a 1-D harmonic
oscillator. The resulting $h_1(t)$ represents a scattering of a soliton-like
pulse on a three-level system.
| [
{
"version": "v1",
"created": "Sat, 17 Jul 1999 15:02:46 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Czachor",
"Marek",
""
],
[
"Doebner",
"Heinz-Dietrich",
""
],
[
"Syty",
"Monika",
""
],
[
"Wasylka",
"Krzysztof",
""
]
] |
quant-ph/9907060 | Afshin Shafiee | Afshin Shafiee and Mehdi Golshani | The Possibility of Factorizable Contextual Hidden Variable Theories | 10 pages, no figure | null | null | null | quant-ph | null | Considering an extended type of Bohm's version of EPR thought experiment, we
derive Bell's inequality for the case of factorizable contextual hidden
variable theories which are consistent with the predictions of quantum theory.
Usually factorizability is associated with non-contextuality. Here, we show
that factorizability is consistent with contextuality, even for the ordinary
Bohm's version of EPR thought experiment.
| [
{
"version": "v1",
"created": "Tue, 20 Jul 1999 08:19:31 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Sep 1999 07:19:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Shafiee",
"Afshin",
""
],
[
"Golshani",
"Mehdi",
""
]
] |
quant-ph/9907061 | Thomas Durt | Thomas Durt | Comment on ``A local hidden variable model of quantum correlations
exploiting the detection loophole'' | 2 pages | null | null | null | quant-ph | null | We study in this short comment the analogies and the differences that exist
between several local hidden variable models.
| [
{
"version": "v1",
"created": "Tue, 20 Jul 1999 09:36:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Durt",
"Thomas",
""
]
] |
quant-ph/9907062 | Dae-Yup | Dae-Yup Song | Periodic Hamiltonian and Berry's phase in harmonic oscillators | 11 pages, no figure, Phys. Rev. A (in press, as a Brief Reprt) An
equality added in Eq.(16) | Phys.Rev.A61:024102,2000 | 10.1103/PhysRevA.61.024102 | null | quant-ph | null | For a time-dependent $\tau$-periodic harmonic oscillator of two linearly
independent homogeneous solutions of classical equation of motion which are
bounded all over the time (stable), it is shown, there is a representation of
states cyclic up to multiplicative constants under $\tau$-evolution or
$2\tau$-evolution depending on the model. The set of the wave functions is
complete. Berry's phase which could depend on the choice of representation can
be defined under the $\tau$- or $2\tau$-evolution in this representation. If a
homogeneous solution diverges as the time goes to infinity, it is shown that,
Berry's phase can not be defined in any representation considered. Berry's
phase for the driven harmonic oscillator is also considered. For the cases
where Berry's phase can be defined, the phase is given in terms of solutions of
the classical equation of motion.
| [
{
"version": "v1",
"created": "Tue, 20 Jul 1999 10:06:28 GMT"
},
{
"version": "v2",
"created": "Tue, 21 Sep 1999 07:55:30 GMT"
},
{
"version": "v3",
"created": "Wed, 20 Oct 1999 08:49:56 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Song",
"Dae-Yup",
""
]
] |
quant-ph/9907063 | Lieven Vandersypen | Costantino S. Yannoni (1), Mark H. Sherwood (1), Lieven M.K.
Vandersypen (1 and 2), Dolores C. Miller (1), Mark G. Kubinec (3), Isaac L.
Chuang (1) ((1) IBM Almaden Research Center (2) Solid State and Photonics
Laboratory, Stanford University (3) College of Chemistry, UC Berkeley) | Nuclear Magnetic Resonance Quantum Computing Using Liquid Crystal
Solvents | Minor changes. Published in Appl. Phys. Lett. v.75, no.22, 29 Nov
1999, p.3563-3565 | null | 10.1063/1.125389 | null | quant-ph | null | Liquid crystals offer several advantages as solvents for molecules used for
nuclear magnetic resonance quantum computing (NMRQC). The dipolar coupling
between nuclear spins manifest in the NMR spectra of molecules oriented by a
liquid crystal permits a significant increase in clock frequency, while short
spin-lattice relaxation times permit fast recycling of algorithms, and save
time in calibration and signal-enhancement experiments. Furthermore, the use of
liquid crystal solvents offers scalability in the form of an expanded library
of spin-bearing molecules suitable for NMRQC. These ideas are demonstrated with
the successful execution of a 2-qubit Grover search using a molecule
($^{13}$C$^{1}$HCl$_3$) oriented in a liquid crystal and a clock speed eight
times greater than in an isotropic solvent. Perhaps more importantly, five
times as many logic operations can be executed within the coherence time using
the liquid crystal solvent.
| [
{
"version": "v1",
"created": "Wed, 21 Jul 1999 00:57:33 GMT"
},
{
"version": "v2",
"created": "Sun, 12 Dec 1999 05:35:31 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Yannoni",
"Costantino S.",
"",
"1 and 2"
],
[
"Sherwood",
"Mark H.",
"",
"1 and 2"
],
[
"Vandersypen",
"Lieven M. K.",
"",
"1 and 2"
],
[
"Miller",
"Dolores C.",
""
],
[
"Kubinec",
"Mark G.",
""
],
[
"Chuang",
"Isaac L.",
""
]
] |
quant-ph/9907064 | Gennadiy Filippov | G.M. Filippov | Interaction of Radiation and a Relativistic Electron in Motion in a
Constant Magnetic Field | 29 pages, no figures | J.Exp.Theor.Phys. 86 (1998) 459; Zh.Eksp.Teor.Fiz. 113 (1998)
841-864 | 10.1134/1.558491 | null | quant-ph | null | The work examines the effect of multiple photon emission on the quantum
mechanical state of an electron emitting synchrotron radiation and on the
intensity of that radiation. Calculations are done with the variant of
perturbation theory based on the use of extended coherent states. A general
formula is derived for the number of emitted photons, which allows for taking
into account their mutual interaction. A model problem is used to demonstrate
the absence of the infrared catastrophe in the modified perturbation theory.
Finally, the electron density matrix is calculated, and the analysis of this
matrix makes it possible to conclude that the degree of the elecron's spatial
localization increases with the passage of time if the electron is being
accelerated.
| [
{
"version": "v1",
"created": "Wed, 21 Jul 1999 08:59:45 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Filippov",
"G. M.",
""
]
] |
quant-ph/9907065 | Levente Horvath | L. Horvath, B. C. Sanders, B. F. Wielinga | Non-simultaneity in two-photon coincidence spectroscopy | 10 page, REVTeXs, 9 Postscript figures | null | null | null | quant-ph | null | Photon coincidence spectroscopy relies on detecting multiphoton emissions
from the combined atom-cavity system in atomic beam cavity quantum
electrodynamics experiments. These multiphoton emissions from the cavity are
nearly simultaneous approximately on the cavity lifetime scale. We determine
the optimal time for the detection window of photon pairs in two-photon
coincidence spectroscopy. If the window time is too short, some photon pairs
will not be detected; if the window time is too long, too many nearly
coincident independent single photons will be falsely interpreted as being a
photon pair. The paper has been submitted to The European Physical Journal D.
| [
{
"version": "v1",
"created": "Wed, 21 Jul 1999 09:05:28 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Horvath",
"L.",
""
],
[
"Sanders",
"B. C.",
""
],
[
"Wielinga",
"B. F.",
""
]
] |
quant-ph/9907066 | Serge Massar | S. Massar and S. Popescu | How much information can be obtained by a quantum measurement? | 13 pages | Phys.Rev. A61 (2000) 062303 | 10.1103/PhysRevA.61.062303 | null | quant-ph | null | How much information about an unknown quantum state can be obtained by a
measurement? We propose a model independent answer: the information obtained is
equal to the minimum entropy of the outputs of the measurement, where the
minimum is taken over all measurements which measure the same ``property'' of
the state. This minimization is necessary because the measurement outcomes can
be redundant, and this redundancy must be eliminated. We show that this minimum
entropy is less or equal than the von Neumann entropy of the unknown states.
That is a measurement can extract at most one meaningful bit from every qubit
carried by the unknown states.
| [
{
"version": "v1",
"created": "Wed, 21 Jul 1999 09:17:44 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Massar",
"S.",
""
],
[
"Popescu",
"S.",
""
]
] |
quant-ph/9907067 | Farrokh Vatan | P. Oscar Boykin, Tal Mor, Vwani Roychowdhury, and Farrokh Vatan | Algorithms on Ensemble Quantum Computers | 16 pages, 4 figures | null | null | null | quant-ph | null | In ensemble (or bulk) quantum computation, measurements of qubits in an
individual computer cannot be performed. Instead, only expectation values can
be measured. As a result of this limitation on the model of computation,
various important algorithms cannot be processed directly on such computers,
and must be modified. We provide modifications of various existing protocols,
including algorithms for universal fault--tolerant computation, Shor's
factorization algorithm (which can be extended to any algorithm computing an NP
function), and some search algorithms to enable processing them on ensemble
quantum computers.
| [
{
"version": "v1",
"created": "Wed, 21 Jul 1999 21:31:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Boykin",
"P. Oscar",
""
],
[
"Mor",
"Tal",
""
],
[
"Roychowdhury",
"Vwani",
""
],
[
"Vatan",
"Farrokh",
""
]
] |
quant-ph/9907068 | Gheorghe-Sorin Paraoanu | Gh.-S. Paraoanu and H. Scutaru | Fidelity for Multimode Thermal Squeezed States | 5 pages, RevTex, submitted to Phys. Rev. A | null | 10.1103/PhysRevA.61.022306 | null | quant-ph | null | In the theory of quantum transmission of information the concept of fidelity
plays a fundamental role. An important class of channels, which can be
experimentally realized in quantum optics, is that of Gaussian quantum
channels. In this work we present a general formula for fidelity in the case of
two arbitrary Gaussian states. From this formula one can get a previous result
(H. Scutaru, J. Phys. A: Mat. Gen {\bf 31}, 3659 (1998)), for the case of a
single mode; or, one can apply it to obtain a closed compact expression for
multimode thermal states.
| [
{
"version": "v1",
"created": "Wed, 21 Jul 1999 23:59:42 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Paraoanu",
"Gh. -S.",
""
],
[
"Scutaru",
"H.",
""
]
] |
quant-ph/9907069 | Francois Gieres | F. Gieres | Mathematical surprises and Dirac's formalism in quantum mechanics | Largely extended and reorganized version, with new title and abstract
and with 2 figures added (published version), 54 pages | Rep.Prog.Phys. 63 (2000) 1893 | 10.1088/0034-4885/63/12/201 | LYCEN 9960a | quant-ph cond-mat hep-th math-ph math.MP nucl-th physics.ed-ph | null | By a series of simple examples, we illustrate how the lack of mathematical
concern can readily lead to surprising mathematical contradictions in wave
mechanics. The basic mathematical notions allowing for a precise formulation of
the theory are then summarized and it is shown how they lead to an elucidation
and deeper understanding of the aforementioned problems. After stressing the
equivalence between wave mechanics and the other formulations of quantum
mechanics, i.e. matrix mechanics and Dirac's abstract Hilbert space
formulation, we devote the second part of our paper to the latter approach: we
discuss the problems and shortcomings of this formalism as well as those of the
bra and ket notation introduced by Dirac in this context. In conclusion, we
indicate how all of these problems can be solved or at least avoided.
| [
{
"version": "v1",
"created": "Thu, 22 Jul 1999 14:40:49 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Dec 2001 16:45:21 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Gieres",
"F.",
""
]
] |
quant-ph/9907070 | Francois Gieres | F. Gieres | Formalisme de Dirac et surprises mathematiques en mecanique quantique | 40 pages, French version of the preprint LYCEN 9960a | null | null | LYCEN 9960b | quant-ph | null | Differents formalismes sont utilises en mecanique quantique pour la
description des etats et des observables : la mecanique ondulatoire, la
mecanique matricielle et le formalisme invariant. Nous discutons les problemes
et inconvenients du formalisme invariant ainsi que ceux de la notation des bras
et kets introduite par Dirac dans ce contexte. Nous indiquons comment tous les
problemes peuvent etre resolus ou du moins evites. Une serie d'exemples
illustre les points souleves et montre comment l'insouciance mathematique peut
aisement conduire a des contradictions mathematiques surprenantes.
| [
{
"version": "v1",
"created": "Thu, 22 Jul 1999 14:59:09 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gieres",
"F.",
""
]
] |
quant-ph/9907071 | James P. Clemens | J. P. Clemens and P. R. Rice | Nonclassical effects in a driven atoms/cavity system in the presence of
arbitrary driving field and dephasing | 8 pages, 10 figures, minor typographical errors corrected, submitted
to Phys Rev A | null | 10.1103/PhysRevA.61.063810 | null | quant-ph | null | We investigate the photon statistics of light transmitted from a driven
optical cavity containing one or two atoms interacting with a single mode of
the cavity field. We treat arbitrary driving fields with emphasis on departure
from previous weak field results. In addition effects of dephasing due to
atomic transit through the cavity mode are included using two different models.
We find that both models show the nonclassical correlations are quite sensitive
to dephasing. The effect of multiple atoms on the system dynamics is
investigated by placing two atoms in the cavity mode at different positions,
therefore having different coupling strengths.
| [
{
"version": "v1",
"created": "Thu, 22 Jul 1999 21:35:51 GMT"
},
{
"version": "v2",
"created": "Wed, 28 Jul 1999 14:49:04 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Clemens",
"J. P.",
""
],
[
"Rice",
"P. R.",
""
]
] |
quant-ph/9907072 | Mladen Pavicic | Mladen Pavicic | Spin correlated interferometry for polarized and unpolarized photons on
a beam splitter | RevTeX, 19 pages, 1 ps figure, author web page at
http://m3k.grad.hr/pavicic | Phys.Rev.A50:3486-3491,1994 | 10.1103/PhysRevA.50.3486 | null | quant-ph | null | Spin interferometry of the 4th order for independent polarized as well as
unpolarized photons arriving simultaneously at a beam splitter and exhibiting
spin correlation while leaving it, is formulated and discussed in the quantum
approach. Beam splitter is recognized as a source of genuine singlet photon
states. Also, typical nonclassical beating between photons taking part in the
interference of the 4th order is given a polarization dependent explanation.
| [
{
"version": "v1",
"created": "Thu, 22 Jul 1999 22:03:06 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Pavicic",
"Mladen",
""
]
] |
quant-ph/9907073 | Timothy C. Ralph | T.C.Ralph | Continuous variable quantum cryptography | 8 pages, 3 figures | Phys.Rev. A61 (2000) 010302 | 10.1103/PhysRevA.61.010302 | null | quant-ph | null | We propose a quantum cryptographic scheme in which small phase and amplitude
modulations of CW light beams carry the key information. The presence of EPR
type correlations provides the quantum protection.
| [
{
"version": "v1",
"created": "Thu, 22 Jul 1999 23:18:42 GMT"
}
] | 2021-05-26T00:00:00 | [
[
"Ralph",
"T. C.",
""
]
] |
quant-ph/9907074 | Doyeol Ahn | D. Ahn, J. H. Oh, K. Kimm, and S. W. Hwang | Time-convolutionless reduced-density-operator theory of a noisy quantum
channel: a two-bit quantum gate for quantum information processing | null | null | 10.1103/PhysRevA.61.052310 | null | quant-ph | null | An exact reduced-density-operator for the output quantum states in
time-convolutionless form was derived by solving the quantum Liouville equation
which governs the dynamics of a noisy quantum channel by using a projection
operator method and both advanced and retarded propagators in time. The
formalism developed in this work is general enough to model a noisy quantum
channel provided specific forms of the Hamiltonians for the system, reservoir,
and the mutual interaction between the system and the reservoir are given.
Then, we apply the formulation to model a two-bit quantum gate composed of
coupled spin systems in which the Heisenberg coupling is controlled by the
tunneling barrier between neighboring quantum dots. Gate Characteristics
including the entropy, fidelity, and purity are calculated numerically for both
mixed and entangled initial states.
| [
{
"version": "v1",
"created": "Fri, 23 Jul 1999 06:30:02 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Ahn",
"D.",
""
],
[
"Oh",
"J. H.",
""
],
[
"Kimm",
"K.",
""
],
[
"Hwang",
"S. W.",
""
]
] |
quant-ph/9907075 | Dr. Bindu A. Bambha- | V. SunilKumar, B. A. Bambah, R. Jagannathan, P. K. Panigrahi and V.
Srinivasan | Coherent States of Non-Linear Lie algebras: Application in Quantum
Optics | 10 pages, Latex | null | 10.1088/1464-4266/2/2/311 | null | quant-ph | null | We present a general unified approach for finding the coherent states of
polynomially deformed algebras such as the quadratic and Higgs algebras, which
are relevant for various multiphoton processes in quantum optics. We give a
general procedure to map these deformed algebras to appropriate Lie algebras.
This is used, for the non compact cases, to obtain the annihilation operator
coherent states, by finding the canonical conjugates of these operators.
Generalized coherent states, in the Perelomov sense also follow from this
construction. This allows us to explicitly construct coherent states associated
with various quantum optical systems.
| [
{
"version": "v1",
"created": "Fri, 23 Jul 1999 20:21:37 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"SunilKumar",
"V.",
""
],
[
"Bambah",
"B. A.",
""
],
[
"Jagannathan",
"R.",
""
],
[
"Panigrahi",
"P. K.",
""
],
[
"Srinivasan",
"V.",
""
]
] |
quant-ph/9907076 | Steve K. Lamoreaux | S.K. Lamoreaux | Experimental Verifications of the Casimir Attractive Force between Solid
Bodies | Submitted to Comments on Atomic and Molecular Physics, H.B.G. Casimir
90th Birthday Commemorative Issue; 2 figures | null | null | LA-UR-99-2515 | quant-ph | null | A brief review of the recent experimental verifications of the Casimir force
between extended bodies is presented. With modern techniques, it now appears
feasible to test the force law with 1% precision; I will address the issues
relating to the interpretation of experiments at this level of accuracy
| [
{
"version": "v1",
"created": "Fri, 23 Jul 1999 21:02:36 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lamoreaux",
"S. K.",
""
]
] |
quant-ph/9907077 | Andreas Winter | Andreas Winter | Coding Theorems of Quantum Information Theory | 80 pages, Ph.D. dissertation, Uni Bielefeld | null | null | null | quant-ph | null | Coding theorems and (strong) converses for memoryless quantum communication
channels and quantum sources are proved: for the quantum source the coding
theorem is reviewed, and the strong converse proven. For classical information
transmission via quantum channels we give a new proof of the coding theorem,
and prove the strong converse, even under the extended model of nonstationary
channels. As a by-product we obtain a new proof of the famous Holevo bound.
Then multi-user systems are investigated, and the capacity region for the
quantum multiple access channel is determined. The last chapter contains a
preliminary discussion of some models of compression of correlated quantum
sources, and a proposal for a program to obtain operational meaning for quantum
conditional entropy. An appendix features the introduction of a notation and
calculus of entropy in quantum systems.
| [
{
"version": "v1",
"created": "Sat, 24 Jul 1999 09:27:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Winter",
"Andreas",
""
]
] |
quant-ph/9907078 | Teimuraz Nadareishvili | Ansor A. Khelashvili, George A. Khelashvili, Nikoloz Kiknadze, Temur
P. Nadareishvili | On the Abnormal Type Anomalous Solutions of Quasipotential Equations | 8 pages, LaTex, no figures | null | null | null | quant-ph | null | It is shown that there exist solutions of the quasipotential equations
exhibiting the abnormal type behaviour of the Bethe-Salpeter equation.
| [
{
"version": "v1",
"created": "Sat, 24 Jul 1999 15:09:33 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Khelashvili",
"Ansor A.",
""
],
[
"Khelashvili",
"George A.",
""
],
[
"Kiknadze",
"Nikoloz",
""
],
[
"Nadareishvili",
"Temur P.",
""
]
] |
quant-ph/9907079 | Alexander Y. Vlasov | Alexander Yu. Vlasov (FRC/IRH) | Quantum Gates and Clifford Algebras | 10 pages AMS-LaTeXe, Poster on TMR Network School on Quantum
Computation and Quantum Information Theory, Italy, Torino, July 12-23 1999
(v2 with tiny changes and typo corrections) | null | null | null | quant-ph | null | Clifford algebras are used for definition of spinors. Because of using
spin-1/2 systems as an adequate model of quantum bit, a relation of the
algebras with quantum information science has physical reasons. But there are
simple mathematical properties of the algebras those also justifies such
applications.
First, any complex Clifford algebra with 2n generators, Cl(2n,C), has
representation as algebra of all 2^n x 2^n complex matrices and so includes
unitary matrix of any quantum n-gate. An arbitrary element of whole algebra
corresponds to general form of linear complex transformation. The last property
is also useful because linear operators are not necessary should be unitary if
they used for description of restriction of some unitary operator to subspace.
The second advantage is simple algebraic structure of Cl(2n) that can be
expressed via tenzor product of standard "building units" and similar with
behavior of composite quantum systems. The compact notation with 2n generators
also can be used in software for modeling of simple quantum circuits by modern
conventional computers.
| [
{
"version": "v1",
"created": "Mon, 26 Jul 1999 21:59:35 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Jul 1999 15:41:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Vlasov",
"Alexander Yu.",
"",
"FRC/IRH"
]
] |
quant-ph/9907080 | Arvind | Eqab M. Rabei and Arvind and R. Simon and N. Mukunda | Bargmann Invariants and Geometric Phases - a Generalised Connection | Accepted for publication in Physical Review A | Phys.Rev.A60:3397,1999 | 10.1103/PhysRevA.60.3397 | null | quant-ph | null | We develop the widest possible generalisation of the well-known connection
between quantum mechanical Bargmann invariants and geometric phases. The key
notion is that of null phase curves in quantum mechanical ray and Hilbert
spaces. Examples of such curves are developed. Our generalisation is shown to
be essential to properly understand geometric phase results in the cases of
coherent states and of Gaussian states. Differential geometric aspects of null
phase curves are also briefly explored.
| [
{
"version": "v1",
"created": "Mon, 26 Jul 1999 05:05:00 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Rabei",
"Eqab M.",
""
],
[
"Arvind",
"",
""
],
[
"Simon",
"R.",
""
],
[
"Mukunda",
"N.",
""
]
] |
quant-ph/9907081 | Peter Loeber | Rudolf Ahlswede and Peter Loeber | Quantum Data Processing | 8 pages | null | null | null | quant-ph | null | We prove a data processing inequality for quantum communication channels,
which states that processing a received quantum state may never increase the
mutual information between input and output states.
| [
{
"version": "v1",
"created": "Mon, 26 Jul 1999 14:22:42 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ahlswede",
"Rudolf",
""
],
[
"Loeber",
"Peter",
""
]
] |
quant-ph/9907082 | Habatwa Vincent Mweene | Habatwa Vincent Mweene (Physics Department, University of Zambia) | New Treatment of Systems of Compounded Angular Momentum | 44 pages, LateX. The notation has been thoroughly revised to improve
comprehension and to facilitate further development of the theory. Some
typographical errors have been corrected | null | null | UNZAPHYS-006 | quant-ph | null | The approach to quantum mechanics which we have used to derive the matrix
treatment of spin from first principles is now employed to treat systems of
compounded angular momentum. A general treatment is first given, which is then
applied to the concrete cases of a spin-0 and a spin-1 system obtained by
adding the spins of two spin-1/2 systems. Thus the probability amplitudes for
measurements on the systems are derived, as well as the matrix vectors and
operators corresponding to the systems. The matrix operators and states
obtained are different from the standard forms and are much more generalized.
The new results are applied to the case of joint measurements on the subsystems
of such a system; this is a problem that has been made very topical by the high
level of interest in the foundations of quantum mechanics. As a consequence of
the insights arising from this treatment, we show that the Clebsch-Gordan
coefficients are amenable to generalization, and we give the generalized forms
for these cases.
| [
{
"version": "v1",
"created": "Mon, 26 Jul 1999 14:56:28 GMT"
},
{
"version": "v2",
"created": "Mon, 18 Oct 1999 15:14:17 GMT"
},
{
"version": "v3",
"created": "Wed, 15 Mar 2000 08:02:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mweene",
"Habatwa Vincent",
"",
"Physics Department, University of Zambia"
]
] |
quant-ph/9907083 | Stefano Mancini | S. Mancini, A. Gatti, L. A. Lugiato | Parametric image amplification in optical cavities | 6 pages, 1 figure | Fortsch.Phys. 48 (2000) 665-669 | 10.1002/(SICI)1521-3978(200005)48:5/7<665::AID-PROP665>3.0.CO;2-4 | null | quant-ph | null | We show the possibility of noiseless amplification of an optical image in
cavities containing a parametric oscillator. We consider a confocal ring cavity
with plane mirrors and compare with the case of planar cavity. In the latter
case the system operates with severe spatial limitations, while in the confocal
case, there is the possibility of preserving the signal-to-noise ratio while
amplifying uniformely the entire image.
| [
{
"version": "v1",
"created": "Mon, 26 Jul 1999 15:21:50 GMT"
}
] | 2016-10-26T00:00:00 | [
[
"Mancini",
"S.",
""
],
[
"Gatti",
"A.",
""
],
[
"Lugiato",
"L. A.",
""
]
] |
quant-ph/9907084 | Stefano Mancini | S. Mancini, V. I. Man'ko | Spectrum of light scattered from a deformed Bose-Einstein condensate | 10 pages, 2 figures, to appear in Phys. Lett. A | Phys.Lett. A259 (1999) 67-70 | 10.1016/S0375-9601(99)00400-4 | null | quant-ph | null | The spectrum of light scattered from a Bose-Einstein condensate is studied in
the limit of particle-number conservation. To this end, a description in terms
of deformed bosons is invoked and this leads to a deviation from the usual
predict spectrum's shape as soon as the number of particles decreases.
| [
{
"version": "v1",
"created": "Mon, 26 Jul 1999 15:38:10 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Mancini",
"S.",
""
],
[
"Man'ko",
"V. I.",
""
]
] |
quant-ph/9907085 | James P. Clemens | J. P. Clemens, P. R. Rice, and L. M. Pedrotti | Output Spectrum of Single-Atom Lasers | 11 pages, 20 figures, minor typographical errors corrected | null | null | null | quant-ph | null | We consider a laser composed of a single atom in a microcavity, with a
coherent or incoherent pump. We consider both three- and four-level gain
schemes, and examine the output spectrum of such lasers. We find that the
linewidth generally scales as the inverse of the photon number. For large
atom-field coupling, a vacuum-Rabi doublet structure is obtained. In the
three-level case, this vacuum-Rabi splitting is apparent only for small
intracavity photon numbers, and vanishes for large pumps. In the four-level
scheme, the vacuum-Rabi structure appears at a nonzero pump level, and is
maintained for large pumps, even when the intracavity photon number is larger
than unity. This behavior is explained utilizing the quantum trajectory
approach.
| [
{
"version": "v1",
"created": "Mon, 26 Jul 1999 18:30:33 GMT"
},
{
"version": "v2",
"created": "Tue, 27 Jul 1999 21:24:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Clemens",
"J. P.",
""
],
[
"Rice",
"P. R.",
""
],
[
"Pedrotti",
"L. M.",
""
]
] |
quant-ph/9907086 | Fabrizio Tamburini | Fabrizio Tamburini, Sergio Ortolani, Antonio Bianchini (Dept. of
Astronomy, University of Padua, Italy) | EPR statistical mixture of correlated states with fractional brownian
process induced by third party interaction | 4 pages, RevteX | null | null | null | quant-ph | null | This paper has been withdrawn by the author(s)
| [
{
"version": "v1",
"created": "Tue, 27 Jul 1999 07:03:08 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Aug 1999 15:01:19 GMT"
},
{
"version": "v3",
"created": "Thu, 25 May 2000 19:56:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Tamburini",
"Fabrizio",
"",
"Dept. of\n Astronomy, University of Padua, Italy"
],
[
"Ortolani",
"Sergio",
"",
"Dept. of\n Astronomy, University of Padua, Italy"
],
[
"Bianchini",
"Antonio",
"",
"Dept. of\n Astronomy, University of Padua, Italy"
]
] |
quant-ph/9907087 | Alexander S. Holevo | A. S. Holevo | Reliability function of general classical-quantum channel | 15 pages, partially reported at the Workshop on Complexity,
Computation and Physics of Information, Cambridge, July 5-23, 1999; to appear
in IEEE Trans. on Information Theory. Several corrections suggested by the
referees are included | null | 10.1109/18.868501 | null | quant-ph | null | In information theory the reliability function and its bounds, describing the
exponential behavior of the error probability, are the most important
quantitative characteristics of the channel performance. From a general point
of view, these bounds provide certain measures of distinguishability of a given
set of states. In an earlier paper we introduced quantum analogs of the random
coding and the expurgation lower bounds for the case of pure signal states.
Here we discuss the general case, in particular, we prove the previously
conjectured expurgation bound and find the quantum cutoff rate in the case of
arbitrary mixed signal states.
| [
{
"version": "v1",
"created": "Tue, 27 Jul 1999 11:36:00 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Jan 2000 08:51:56 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Holevo",
"A. S.",
""
]
] |
quant-ph/9907088 | Kwek LC | Xiang-Bin Wang, C.H. Oh and L.C. Kwek | On Bures fidelity of displaced squeezed thermal states | 10 pages with RevTex required | Phys.Rev.A58:4186,1998 | 10.1103/PhysRevA.58.4186 | null | quant-ph astro-ph | null | Fidelity plays a key role in quantum information and communication theory.
Fidelity can be interpreted as the probability that a decoded message possesses
the same information content as the message prior to coding and transmission.
In this paper, we give a formula of Bures fidelity for displaced squeezed
thermal states directly by the displacement and squeezing parameters and
birefly discuss how the results can apply to quantum information theory.
| [
{
"version": "v1",
"created": "Tue, 27 Jul 1999 12:45:49 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Wang",
"Xiang-Bin",
""
],
[
"Oh",
"C. H.",
""
],
[
"Kwek",
"L. C.",
""
]
] |
quant-ph/9907090 | Eduard Schmidt | Eduard Schmidt, Ludwig Knoell, and Dirk-Gunnar Welsch | Nonclassical correlations in damped N-solitons | 4 pages, RevTeX, 2 PS-figures, contribution to the Sixth
International Conference on Squeezed states and Uncertainty relations ICSSUR
VI, Naples 24-29 May 1999 | null | null | FSU TPI QO-07/99 | quant-ph | null | The quantum statistics of damped higher-order optical solitons are analyzed
numerically, using cumulant-expansion techniques in Gaussian approximation. A
detailed analysis of nonclassical properties in both the time and the frequency
domain is given, with special emphasis on the role of absorption. Highly
nonclassical broadband spectral correlation is predicted.
| [
{
"version": "v1",
"created": "Tue, 27 Jul 1999 16:14:55 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Jul 1999 21:17:10 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Schmidt",
"Eduard",
""
],
[
"Knoell",
"Ludwig",
""
],
[
"Welsch",
"Dirk-Gunnar",
""
]
] |
quant-ph/9907091 | Massimiliano F. Sacchi | G. M. D'Ariano, L. Maccone, M. F. Sacchi, A. Garuccio | Tomographic test of Bell's inequality | RevTex. 8 pages, 3 ps figures. To appear on J. Opt. B | J.Opt.B1:576,1999 | 10.1088/1464-4266/1/5/314 | null | quant-ph | null | We present a homodyne detection scheme to verify Bell's inequality on
correlated optical beams at the output of a nondegenerate parametric amplifier.
Our approach is based on tomographic measurement of the joint detection
probabilities, which allows high quantum efficiency at detectors. A
self-homodyne scheme is suggested to simplify the experimental set-up.
| [
{
"version": "v1",
"created": "Wed, 28 Jul 1999 09:28:49 GMT"
}
] | 2011-03-28T00:00:00 | [
[
"D'Ariano",
"G. M.",
""
],
[
"Maccone",
"L.",
""
],
[
"Sacchi",
"M. F.",
""
],
[
"Garuccio",
"A.",
""
]
] |
quant-ph/9907092 | Ned Lynne Floyd | Edward R. Floyd | Classical Limit of the Trajectory Representation of Quantum Mechanics,
Loss of Information and Residual Indeterminacy | 12 pages LaTeX 2.09. No figures. Accepted by Int. J. Mod. Phys. A.
Minor revisions to conform with galley proofs. Acknowledgements expanded.
References updated. Key words: classical limits, trajectory interpretation,
Planck's correspondence principle, residual indeterminacy, 't Hooft's
information loss and equivalence classes, Heisenberg uncertainty principle.
Subj-clas: Quantum Physics; Mathematical Physics | Int.J.Mod.Phys. A15 (2000) 1363-1378 | 10.1142/S0217751X00000604 | null | quant-ph hep-th math-ph math.MP | null | The trajectory representation in the classical limit (\hbar \to 0) manifests
a residual indeterminacy. We show that the trajectory representation in the
classical limit goes to neither classical mechanics (Planck's correspondence
principle) nor statistical mechanics. This residual indeterminacy is contrasted
to Heisenberg uncertainty. We discuss the relationship between indeterminacy
and 't Hooft's information loss and equivalence classes.
| [
{
"version": "v1",
"created": "Wed, 28 Jul 1999 14:56:59 GMT"
},
{
"version": "v2",
"created": "Sat, 27 Nov 1999 05:54:13 GMT"
},
{
"version": "v3",
"created": "Sat, 12 Feb 2000 17:26:57 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Floyd",
"Edward R.",
""
]
] |
quant-ph/9907093 | James P. Clemens | J. P. Clemens, P. R. Rice, P. K. Rungta, and R. J. Brecha | Two-Level Atom in an Optical Parametric Oscillator: Spectra of
Transmitted and Fluorescent Fields in the Weak Driving Field Limit | 10 pages, 17 figures, submitted to Phys Rev A | null | 10.1103/PhysRevA.62.033802 | null | quant-ph | null | We consider the interaction of a two-level atom inside an optical parametric
oscillator. In the weak driving field limit, we essentially have an atom-cavity
system driven by the occasional pair of correlated photons, or weakly squeezed
light. We find that we may have holes, or dips, in the spectrum of the
fluorescent and transmitted light. This occurs even in the strong-coupling
limit when we find holes in the vacuum-Rabi doublet. Also, spectra with a
sub-natural linewidth may occur. These effects disappear for larger driving
fields, unlike the spectral narrowing obtained in resonance fluorescence in a
squeezed vacuum; here it is important that the squeezing parameter $N$ tends to
zero so that the system interacts with only one correlated pair of photons at a
time. We show that a previous explanation for spectral narrowing and spectral
holes for incoherent scattering is not applicable in the present case, and
propose a new explanation. We attribute these anomalous effects to quantum
interference in the two-photon scattering of the system.
| [
{
"version": "v1",
"created": "Wed, 28 Jul 1999 19:11:52 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Clemens",
"J. P.",
""
],
[
"Rice",
"P. R.",
""
],
[
"Rungta",
"P. K.",
""
],
[
"Brecha",
"R. J.",
""
]
] |
quant-ph/9907094 | Jose L. Cereceda | Jose L. Cereceda | A simple proof of the converse of Hardy's theorem | LaTeX, 16 pages + 2 eps figures | null | null | null | quant-ph | null | In this paper we provide a simple proof of the fact that for a system of two
spin-1/2 particles, and for a choice of observables, there is a unique state
which shows Hardy-type nonlocality. Moreover, an explicit expression for the
probability that an ensemble of particle pairs prepared in such a state
exhibits a Hardy-type nonlocality contradiction is given in terms of two
independent parameters related to the observables involved. Incidentally, a
wrong statement expressed in Mermin's proof of the converse [N.D. Mermin, Am.
J. Phys. 62, 880 (1994)] is pointed out.
| [
{
"version": "v1",
"created": "Wed, 28 Jul 1999 20:03:42 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cereceda",
"Jose L.",
""
]
] |
quant-ph/9907095 | Jean-Michel Courty | Jean-Michel Courty, Serge Reynaud, (Laboratoire Kastler Brossel) | Quantum fluctuations for drag free geodesic motion | 4 pages, 1 figure, RevTeX, minor changes | J.Opt.B Quant.Semiclass.Opt. 2 (2000) 90-93 | 10.1088/1464-4266/2/2/304 | null | quant-ph | null | The drag free technique is used to force a proof mass to follow a geodesic
motion. The mass is protected from perturbations by a cage, and the motion of
the latter is actively controlled to follow the motion of the proof mass. We
present a theoretical analysis of the effects of quantum fluctuations for this
technique. We show that a perfect drag free operation is in principle possible
at the quantum level, in spite of the back action exerted on the mass by the
position sensor.
| [
{
"version": "v1",
"created": "Thu, 29 Jul 1999 14:11:04 GMT"
},
{
"version": "v2",
"created": "Tue, 14 Dec 1999 13:46:57 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Courty",
"Jean-Michel",
""
],
[
"Reynaud",
"Serge",
""
]
] |
quant-ph/9907096 | Dr. Daniel A. Lidar | Daniel A. Lidar, David Bacon, Julia Kempe and K. Birgitta Whaley | Protecting Quantum Information Encoded in Decoherence Free States
Against Exchange Errors | 7 pages, no figures. Discussion in section V.A. significantly
expanded. Several small changes. Two authors added | Phys. Rev. A Vol. 61(5), p. 52307 (2000) | 10.1103/PhysRevA.61.052307 | null | quant-ph cond-mat | null | The exchange interaction between identical qubits in a quantum information
processor gives rise to unitary two-qubit errors. It is shown here that
decoherence free subspaces (DFSs) for collective decoherence undergo Pauli
errors under exchange, which however do not take the decoherence free states
outside of the DFS. In order to protect DFSs against these errors it is
sufficient to employ a recently proposed concatenated DFS-quantum error
correcting code scheme [D.A. Lidar, D. Bacon and K.B. Whaley, Phys. Rev. Lett.
{\bf 82}, 4556 (1999)].
| [
{
"version": "v1",
"created": "Thu, 29 Jul 1999 19:51:14 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Aug 1999 21:20:20 GMT"
},
{
"version": "v3",
"created": "Thu, 2 Dec 1999 21:28:54 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Lidar",
"Daniel A.",
""
],
[
"Bacon",
"David",
""
],
[
"Kempe",
"Julia",
""
],
[
"Whaley",
"K. Birgitta",
""
]
] |
quant-ph/9907097 | GuangCan Guo | Chuan-Wei Zhang, Zi-Yang Wang, Chuan-Feng Li, and Guang-Can Guo
(University of Science and Technology of China) | Realizing probabilistic identification and cloning of quantum states via
universal quantum logic gates | 9 Pages, 7 Figures, REVTeX, final version | Phys. Rev. A 61, 062310 (2000) | 10.1103/PhysRevA.61.062310 | null | quant-ph | null | Probabilistic quantum cloning and identifying machines can be constructed via
unitary-reduction processes [Duan and Guo, Phys. Rev. Lett. 80, 4999 (1998)].
Given the cloning (identifying) probabilities, we derive an explicit
representation of the unitary evolution and corresponding Hamiltonian to
realize probabilistic cloning (identification). The logic networks are obtained
by decomposing the unitary representation into universal quantum logic
operations. The robustness of the networks is also discussed. Our method is
suitable for a $k$-partite system, such as quantum computer, and may be
generalized to general state-dependent cloning and identification.
| [
{
"version": "v1",
"created": "Fri, 30 Jul 1999 02:19:16 GMT"
},
{
"version": "v2",
"created": "Sat, 22 Jan 2000 08:34:43 GMT"
},
{
"version": "v3",
"created": "Sun, 28 May 2000 14:16:49 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Zhang",
"Chuan-Wei",
"",
"University of Science and Technology of China"
],
[
"Wang",
"Zi-Yang",
"",
"University of Science and Technology of China"
],
[
"Li",
"Chuan-Feng",
"",
"University of Science and Technology of China"
],
[
"Guo",
"Guang-Can",
"",
"University of Science and Technology of China"
]
] |
quant-ph/9907098 | Guifre Vidal Bonafont | Rolf Tarrach and Guifre Vidal | Universality of optimal measurements | Revtex, 5 pages, no figures | Phys. Rev. A 60, R3339 (1999) | 10.1103/PhysRevA.60.R3339 | null | quant-ph | null | We present optimal and minimal measurements on identical copies of an unknown
state of a qubit when the quality of measuring strategies is quantified with
the gain of information (Kullback of probability distributions). We also show
that the maximal gain of information occurs, among isotropic priors, when the
state is known to be pure. Universality of optimal measurements follows from
our results: using the fidelity or the gain of information, two different
figures of merits, leads to exactly the same conclusions. We finally
investigate the optimal capacity of $N$ copies of an unknown state as a quantum
channel of information.
| [
{
"version": "v1",
"created": "Fri, 30 Jul 1999 07:47:15 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Tarrach",
"Rolf",
""
],
[
"Vidal",
"Guifre",
""
]
] |
quant-ph/9907099 | Sergei Kulik | A.V.Burlakov, M.V.Chekhova, O.A.Karabutova, D.N.Klyshko, and S.P.Kulik | Polarization state of a biphoton: quantum ternary logic | null | null | 10.1103/PhysRevA.60.R4209 | null | quant-ph | null | Polarization state of biphoton light generated via collinear
frequency-degenerate spontaneous parametric down-conversion is considered. A
biphoton is described by a three-component polarization vector, its arbitrary
transformations relating to the SU(3) group. A subset of such transformations,
available with retardation plates, is realized experimentally. In particular,
two independent orthogonally polarized beams of type-I biphotons are
transformed into a beam of type-II biphotons. Polarized biphotons are suggested
as ternary analogs of two-state quantum systems (qubits).
| [
{
"version": "v1",
"created": "Fri, 30 Jul 1999 08:01:19 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Burlakov",
"A. V.",
""
],
[
"Chekhova",
"M. V.",
""
],
[
"Karabutova",
"O. A.",
""
],
[
"Klyshko",
"D. N.",
""
],
[
"Kulik",
"S. P.",
""
]
] |
quant-ph/9907100 | Walter T. Strunz | Walter T. Strunz, Lajos Diosi, Nicolas Gisin, and Ting Yu | Quantum trajectories for Brownian motion | 4 pages, 3 eps figures | Phys. Rev. Lett. 83, 4909 (1999) | 10.1103/PhysRevLett.83.4909 | null | quant-ph | null | We present the stochastic Schroedinger equation for the dynamics of a quantum
particle coupled to a high temperature environment and apply it the dynamics of
a driven, damped, nonlinear quantum oscillator. Apart from an initial slip on
the environmental memory time scale, in the mean, our result recovers the
solution of the known non-Lindblad quantum Brownian motion master equation. A
remarkable feature of our approach is its localization property: individual
quantum trajectories remain localized wave packets for all times, even for the
classically chaotic system considered here, the localization being stronger the
smaller $\hbar$.
| [
{
"version": "v1",
"created": "Fri, 30 Jul 1999 12:10:17 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Strunz",
"Walter T.",
""
],
[
"Diosi",
"Lajos",
""
],
[
"Gisin",
"Nicolas",
""
],
[
"Yu",
"Ting",
""
]
] |
quant-ph/9907101 | Stefan Weigert | Stefan Weigert | Expanding Hermitean Operators in a Basis of Projectors on Coherent Spin
States | Latex2e, 4 pages | J. Opt. B 56 (2004) 489 | 10.1088/1464-4266/6/12/001 | null | quant-ph | null | The expectation values of a hermitean operator A in (2s+1)(2s+1) specific
coherent states of a spin are known to determine the operator unambiguously. As
shown here, (almost) any other (2s+1)(2s+1) coherent states also provide a
basis for self-adjoint operators. This is proven by considering the determinant
of the Gram matrix associated with the coherent state projectors as a
Hamiltonian of a fictitious classical spin system.
| [
{
"version": "v1",
"created": "Fri, 30 Jul 1999 12:37:15 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Weigert",
"Stefan",
""
]
] |
quant-ph/9907102 | Lutz Polley | L. Polley | Quantization via hopping amplitudes: Schroedinger equation and free QED | LaTeX2e, 12 pages, no figures | null | null | null | quant-ph | null | Schroedinger's equation with scalar and vector potentials is shown to
describe "nothing but" hopping of a quantum particle on a lattice; any spatial
variation of the hopping amplitudes acts like an external electric and/or
magnetic field. The main point of the argument is the superposition principle
for state vectors; Lagrangians, path integrals, or classical Hamiltonians are
not (!) required. Analogously, the Hamiltonian of the free electromagnetic
field is obtained as a twofold continuum limit of unitary hopping in Z(N) link
configuration space, if gauge invariance and C and P symmetries are imposed.
| [
{
"version": "v1",
"created": "Fri, 30 Jul 1999 12:46:02 GMT"
},
{
"version": "v2",
"created": "Fri, 3 Mar 2000 14:48:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Polley",
"L.",
""
]
] |
quant-ph/9907103 | Jiannis Pachos | Jiannis Pachos, Paolo Zanardi and Mario Rasetti | Non-Abelian Berry connections for quantum computation | 5 pages, no figures, revtex, minor changes, version accepted by Phys.
Rev A (rapid comm.) | Phys.Rev. A61 (2000) 010305 | 10.1103/PhysRevA.61.010305 | null | quant-ph hep-th | null | In the holonomic approach to quantum computation information is encoded in a
degenerate eigenspace of a parametric family of Hamiltonians and manipulated by
the associated holonomic gates. These are realized in terms of the non-abelian
Berry connection and are obtained by driving the control parameters along
adiabatic loops. We show how it is possible, for a specific model, to
explicitly determine the loops generating any desired logical gate, thus
producing a universal set of unitary transformations. In a multi-partite system
unitary transformations can be implemented efficiently by sequences of local
holonomic gates. Moreover a conceptual scheme for obtaining the required
Hamiltonian family, based on frequently repeated pulses, is discussed, together
with a possible process whereby the initial state can be prepared and the final
one can be measured.
| [
{
"version": "v1",
"created": "Fri, 30 Jul 1999 13:39:28 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Nov 1999 16:10:10 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Pachos",
"Jiannis",
""
],
[
"Zanardi",
"Paolo",
""
],
[
"Rasetti",
"Mario",
""
]
] |
Subsets and Splits