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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9909004 | Pinaki Roy | Geza Levai and Pinaki Roy | Conditionally Exactly Solvable Potentials and Supersymmetric
Transformations | 10 pages,Reference added | null | 10.1016/S0375-9601(99)00778-1 | null | quant-ph | null | A general procedure is presented to construct conditionally solvable (CES)
potentials using the techniques of supersymmetric quantum mechanics.The method
is illustrated with potentials related to the harmonic oscillator
problem.Besides recovering known results,new CES potentials are also obtained
within the framework of this general approach.The conditions under which this
method leads to CES potentials are also discussed.
| [
{
"version": "v1",
"created": "Wed, 1 Sep 1999 12:40:58 GMT"
},
{
"version": "v2",
"created": "Wed, 8 Sep 1999 08:38:34 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Levai",
"Geza",
""
],
[
"Roy",
"Pinaki",
""
]
] |
quant-ph/9909005 | Anu Venugopalan | Anu Venugopalan | Pointer states via Decoherence in a Quantum Measurement | 9 pages, LaTex, communicated to Physical Review A | null | 10.1103/PhysRevA.61.012102 | null | quant-ph | null | We consider the interaction of a quantum system (spin-1/2) with a macroscopic
quantum apparatus (harmonic oscillator) which in turn is coupled to a bath of
harmonic oscillators. Exact solutions of the Markovian Master equation show
that the reduced density matrix of the system-apparatus combine decoheres to a
statistical mixture where up and down spins eventually correlate with pointer
states of the apparatus. For the zero temperature bath these pointer states
turn out to be coherent states of the harmonic oscillator for arbitrary initial
states of the apparatus. For a high temperature bath pointer states are
Gaussian distributions (generalized coherent states). For both cases, the
off-diagonal elements in spin-space decohere over a time scale which goes
inversely as the square of the "separation" between the "pointers". Our exact
results also demonstrate in an unambiguous way that the pointer states in this
measurement model emerge independent of the initial state of the apparatus.
| [
{
"version": "v1",
"created": "Wed, 1 Sep 1999 17:15:28 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Venugopalan",
"Anu",
""
]
] |
quant-ph/9909006 | Mark Hillery | Mark Hillery | Quantum cryptography with squeezed states | 15 pages, no figures | null | 10.1103/PhysRevA.61.022309 | null | quant-ph | null | A quantum key distribution scheme based on the use of displaced squeezed
vacuum states is presented. The states are squeezed in one of two field
quadrature components, and the value of the squeezed component is used to
encode a character from an alphabet. The uncertainty relation between
quadrature components prevents an eavesdropper from determining both with
enough precision to determine the character being sent. Losses degrade the
performance of this scheme, but it is possible to use phase-sensitive
amplifiers to boost the signal and partially compensate for their effect.
| [
{
"version": "v1",
"created": "Wed, 1 Sep 1999 21:38:32 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Hillery",
"Mark",
""
]
] |
quant-ph/9909007 | Simon Benjamin | S. C. Benjamin (Univ. of Oxford) | Schemes for Parallel Quantum Computation Without Local Control of Qubits | 12 pages + 3 figures. Several small corrections made | null | 10.1103/PhysRevA.61.020301 | null | quant-ph | null | Typical quantum computing schemes require transformations (gates) to be
targeted at specific elements (qubits). In many physical systems, direct
targeting is difficult to achieve; an alternative is to encode local gates into
globally applied transformations. Here we demonstrate the minimum physical
requirements for such an approach: a one-dimensional array composed of two
alternating 'types' of two-state system. Each system need be sensitive only to
the net state of its nearest neighbors, i.e. the number in state 1 minus the
number in state 2. Additionally, we show that all such arrays can perform quite
general parallel operations. A broad range of physical systems and interactions
are suitable: we highlight two potential implementations.
| [
{
"version": "v1",
"created": "Thu, 2 Sep 1999 18:35:27 GMT"
},
{
"version": "v2",
"created": "Sat, 18 Sep 1999 16:59:24 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Benjamin",
"S. C.",
"",
"Univ. of Oxford"
]
] |
quant-ph/9909008 | Alexander A. Kokin | K. A. Valiev and A. A. Kokin (Institute of Physics and Technology,
Russian Academy of Sciences) | Solid-state NMR quantum computer with individual access to qubits and
some its ensemble developments | LaTex 21 pages, 4 EPS figures; Figure 2 changed | null | null | null | quant-ph | null | Here we made an analysis of the principles of a semiconductor NMR quantum
computer and its developments. The known variant of an individual-access
computer (B. Kane) and alternative solid-state bulk-ensemble approach versions
allowing to avoid some difficulties in implementing the first variant are
considered.
| [
{
"version": "v1",
"created": "Thu, 2 Sep 1999 07:37:02 GMT"
},
{
"version": "v2",
"created": "Mon, 15 Nov 1999 16:31:29 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Valiev",
"K. A.",
"",
"Institute of Physics and Technology,\n Russian Academy of Sciences"
],
[
"Kokin",
"A. A.",
"",
"Institute of Physics and Technology,\n Russian Academy of Sciences"
]
] |
quant-ph/9909009 | W. A. Hofer | W. A. Hofer | On interference: the scalar problem | Six pages (RevTeX) and four figures (eps). For a full list of
available papers see http://info.tuwien.ac.at/cms/wh/ | null | null | MW-99-03 | quant-ph hep-th | null | Single-slit and two-slit interferometer measurements of electrons are
analyzed within the realistic model of particle propagation. In a step by step
procedure we show that all current models of interference are essentially
non-local and demonstrate that the treatment of the quantum theory of motion is
the simplest model for the scalar problem. In particular we give a novel
interpretation of the quantum potential Q, which should be regarded as a
non-classical and essentially statistical term describing the changes of the
quantum ensemble due to a change of the physical environment.
| [
{
"version": "v1",
"created": "Thu, 2 Sep 1999 09:35:14 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hofer",
"W. A.",
""
]
] |
quant-ph/9909010 | Benni Reznik | Aharon Casher and Benni Reznik | Back-Reaction of Clocks and Limitations on Observability in Closed
Systems | 18 pages, 4 figures | Phys.Rev. A62 (2000) 042104 | 10.1103/PhysRevA.62.042104 | null | quant-ph gr-qc | null | Measurements are ordinarily described with respect to absolute "Newtonian"
time. In reality however, the switching-on of the measuring device at the
instance of the measurement requires a timing device. Hence the classical time
$t$ must be replaced by a suitable quantum time variable $\tau$ of a physical
clock. The main issue raised in this article is that while doing so, we can no
longer neglect the {\em back-reaction} due to the measurement on the clock.
This back-reaction yields a bound on the accuracy of the measurement. When this
bound is violated the result of a measurement is generally not an eigenvalue of
the observable, and furthermore, the state of the system after the measurement
is generally not a pure state. We argue that as a consequence, a sub-class of
observables in a closed system cannot be realized by a measurement.
| [
{
"version": "v1",
"created": "Thu, 2 Sep 1999 13:07:10 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Casher",
"Aharon",
""
],
[
"Reznik",
"Benni",
""
]
] |
quant-ph/9909011 | Leah Henderson | L. Henderson and V. Vedral | Information, Relative Entropy of Entanglement and Irreversibility | 10 pages, no figures | Physical Review Letters, vol. 84, 10, pp.2263-6, 2000 | 10.1103/PhysRevLett.84.10 | null | quant-ph | null | Previously proposed measures of entanglement, such as entanglement of
formation and assistance, are shown to be special cases of the relative entropy
of entanglement. The difference between these measures for an ensemble of mixed
states is shown to depend on the availability of classical information about
particular members of the ensemble. Based on this, relations between relative
entropy of entanglement and mutual information are derived.
| [
{
"version": "v1",
"created": "Thu, 2 Sep 1999 16:20:21 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Henderson",
"L.",
""
],
[
"Vedral",
"V.",
""
]
] |
quant-ph/9909012 | Tomoyuki Yamakami | Tomoyuki Yamakami | Analysis of Quantum Functions | The complete version of the conference paper appeared in the
Proceedings of the 19th International Conference on the Foundations of
Software Technology and Theoretical Computer Science, Lecture Notes in
Computer Science, Springer-Verlag, Vol.1738, pp.407-419, 1999 | International Journal of Foundations of Computer Science,
Vol.14(5), pp.815-852, October 2003. | null | null | quant-ph cs.CC | null | This paper initiates a systematic study of quantum functions, which are
(partial) functions defined in terms of quantum mechanical computations. Of all
quantum functions, we focus on resource-bounded quantum functions whose inputs
are classical bit strings. We prove complexity-theoretical properties and
unique characteristics of these quantum functions by recent techniques
developed for the analysis of quantum computations. We also discuss relativized
quantum functions that make adaptive and nonadaptive oracle queries.
| [
{
"version": "v1",
"created": "Thu, 2 Sep 1999 17:23:26 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Sep 1999 21:09:31 GMT"
},
{
"version": "v3",
"created": "Fri, 1 Nov 2002 18:50:05 GMT"
},
{
"version": "v4",
"created": "Thu, 7 Aug 2003 13:12:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Yamakami",
"Tomoyuki",
""
]
] |
quant-ph/9909013 | Holger F. Hofmann | Holger F. Hofmann | Nonclassical correlations of phase noise and photon number in quantum
nondemolition measurements | 16 pages, 5 figures, final version to be published in Phys. Rev. A,
Clarifications of the nature of the measurement result and the noise added in
section II | Phys. Rev. A 61, 033815 (2000) | 10.1103/PhysRevA.61.033815 | null | quant-ph physics.optics | null | The continuous transition from a low resolution quantum nondemolition
measurement of light field intensity to a precise measurement of photon number
is described using a generalized measurement postulate. In the intermediate
regime, quantization appears as a weak modulation of measurement probability.
In this regime, the measurement result is strongly correlated with the amount
of phase decoherence introduced by the measurement interaction. In particular,
the accidental observation of half integer photon numbers preserves phase
coherence in the light field, while the accidental observation of quantized
values increases decoherence. The quantum mechanical nature of this correlation
is discussed and the implications for the general interpretation of
quantization are considered.
| [
{
"version": "v1",
"created": "Fri, 3 Sep 1999 07:37:57 GMT"
},
{
"version": "v2",
"created": "Wed, 1 Dec 1999 08:27:31 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Hofmann",
"Holger F.",
""
]
] |
quant-ph/9909014 | Andreas Klappenecker | Andreas Klappenecker | Wavelets and Wavelet Packets on Quantum Computers | 11 pages, 10 postscript figure, to appear in Proc. of Wavelet
Applications in Signal and Image Processing VII | null | 10.1117/12.366826 | null | quant-ph | null | We show how periodized wavelet packet transforms and periodized wavelet
transforms can be implemented on a quantum computer. Surprisingly, we find that
the implementation of wavelet packet transforms is less costly than the
implementation of wavelet transforms on a quantum computer.
| [
{
"version": "v1",
"created": "Fri, 3 Sep 1999 19:32:42 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Klappenecker",
"Andreas",
""
]
] |
quant-ph/9909015 | P. Narayana Swamy | P. Narayana Swamy | q-deformed fermion oscillators, zero-point energy and
inclusion-exclusion principle | 10 pages, Latex, submitted to Physical Review E | null | null | null | quant-ph | null | The theory of Fermion oscillators has two essential ingredients: zero-point
energy and Pauli exclusion principle. We devlop the theory of the statistical
mechanics of generalized q-deformed Fermion oscillator algebra with inclusion
principle (i.e., without the exclusion principle), which corresponds to
ordinary fermions with Pauli exclusion principle in the classical limit $q \to
1$. Some of the remarkable properties of this theory play a crucial role in the
understanding of the q-deformed Fermions. We show that if we insist on the weak
exclusion principle, then the theory has the expected low temperature limit as
well as the correct classical q-limit.
| [
{
"version": "v1",
"created": "Fri, 3 Sep 1999 19:07:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Swamy",
"P. Narayana",
""
]
] |
quant-ph/9909016 | Hans Halvorson | Rob Clifton (Depts. of Philosophy and History & Philosophy of Science,
University of Pittsburgh), Hans Halvorson (Depts. of Mathematics and
Philosophy, University of Pittsburgh), Adrian Kent (DAMTP, University of
Cambridge) | Non-local Correlations are Generic in Infinite-Dimensional Bipartite
Systems | 8 pages, RevTeX | Phys. Rev. A 61, 042101 (2000) | 10.1103/PhysRevA.61.042101 | null | quant-ph | null | It was recently shown that the nonseparable density operators for a bipartite
system are trace norm dense if either factor space has infinite dimension. We
show here that non-local states -- i.e., states whose correlations cannot be
reproduced by any local hidden variable model -- are also dense. Our
constructions distinguish between the cases where both factor spaces are
infinite-dimensional, where we show that states violating the CHSH inequality
are dense, and the case where only one factor space is infinite-dimensional,
where we identify open neighborhoods of nonseparable states that do not violate
the CHSH inequality but show that states with a subtler form of non-locality
(often called "hidden" non-locality) remain dense.
| [
{
"version": "v1",
"created": "Fri, 3 Sep 1999 22:38:13 GMT"
},
{
"version": "v2",
"created": "Fri, 3 Sep 1999 23:02:14 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Clifton",
"Rob",
"",
"Depts. of Philosophy and History & Philosophy of Science,\n University of Pittsburgh"
],
[
"Halvorson",
"Hans",
"",
"Depts. of Mathematics and\n Philosophy, University of Pittsburgh"
],
[
"Kent",
"Adrian",
"",
"DAMTP, University of\n Cambridge"
]
] |
quant-ph/9909017 | Hagen Kleinert | Boris Kastening and Hagen Kleinert | Efficient Algorithm for Perturbative Calculation of Multiloop Feynman
Integrals | Author Information under
http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of
paper also at http://www.physik.fu-berlin.de/~kleinert/299 | Phys.Lett. A269 (2000) 50-54 | 10.1016/S0375-9601(00)00199-7 | null | quant-ph | null | We present an efficient algorithm for calculating multiloop Feynman integrals
perturbatively.
| [
{
"version": "v1",
"created": "Sat, 4 Sep 1999 06:56:45 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Oct 1999 06:54:49 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Kastening",
"Boris",
""
],
[
"Kleinert",
"Hagen",
""
]
] |
quant-ph/9909018 | Dimitris G. Angelakis | D. G. Angelakis, E. Paspalakis and P. L. Knight | Transient properties of modified reservoir-induced transparency | 4 pages RevTex, including 3 figures. To appear in Phys. Rev. A | Phys. Rev. A 61, 055802 (2000) | 10.1103/PhysRevA.61.055802 | null | quant-ph | null | We investigate the transient response of a $\Lambda$-type system with one
transition decaying to a modified radiation reservoir with an inverse
square-root singular density of modes at threshold, under conditions of
transparency. We calculate the time evolution of the linear susceptibility for
the probe laser field and show that, depending on the strength of the coupling
to the modified vacuum and the background decay, the probe transmission can
exhibit behaviour ranging from underdamped to overdamped oscillations.
Transient gain without population inversion is also possible depending on the
system's parameters.
| [
{
"version": "v1",
"created": "Sat, 4 Sep 1999 18:13:11 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Jan 2000 15:51:24 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Angelakis",
"D. G.",
""
],
[
"Paspalakis",
"E.",
""
],
[
"Knight",
"P. L.",
""
]
] |
quant-ph/9909019 | Martti Havukainen | Martti Havukainen | Comparisons of spectra determined using detector atoms and spatial
correlation functions | 8 pages, 8 figures | null | 10.1080/09500340008232165 | HIP-1999-50/TH | quant-ph | null | We show how two level atoms can be used to determine the local time dependent
spectrum. The method is applied to a one dimensional cavity. The spectrum
obtained is compared with the mode spectrum determined using spatially filtered
second order correlation functions. The spectra obtained using two level atoms
give identical results with the mode spectrum. One benefit of the method is
that only one time averages are needed. It is also more closely related to a
realistic measurement scheme than any other definition of a time dependent
spectrum.
| [
{
"version": "v1",
"created": "Mon, 6 Sep 1999 08:43:29 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Havukainen",
"Martti",
""
]
] |
quant-ph/9909020 | Michael Nielsen | M. A. Nielsen | Probability distributions consistent with a mixed state | 6 pages, submitted to Physical Review A | Physical Review A 61 (6): Art. No. 064301 (2000) | 10.1103/PhysRevA.62.052308 | null | quant-ph | null | A density matrix $\rho$ may be represented in many different ways as a
mixture of pure states, $\rho = \sum_i p_i |\psi_i\ra \la \psi_i|$. This paper
characterizes the class of probability distributions $(p_i)$ that may appear in
such a decomposition, for a fixed density matrix $\rho$. Several illustrative
applications of this result to quantum mechanics and quantum information theory
are given.
| [
{
"version": "v1",
"created": "Mon, 6 Sep 1999 08:38:24 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Nielsen",
"M. A.",
""
]
] |
quant-ph/9909021 | Andrew Scott Parkins | A.S. Parkins and H.J. Kimble | Proposal for teleportation of the wave function of a massive particle | 4 pages, 3 figures | null | null | null | quant-ph | null | We propose a scheme for teleporting an atomic center-of-mass wave function
between distant locations. The scheme uses interactions in cavity quantum
electrodynamics to facilitate a coupling between the motion of an atom trapped
inside a cavity and external propagating light fields. This enables the
distribution of quantum entanglement and the realization of the required
motional Bell-state analysis.
| [
{
"version": "v1",
"created": "Mon, 6 Sep 1999 23:33:06 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Parkins",
"A. S.",
""
],
[
"Kimble",
"H. J.",
""
]
] |
quant-ph/9909022 | Piotr Rozmej | R.Arvieu (ISN, Grenoble, France) and P.Rozmej (University MCS, Lublin,
Poland) | Squeezed angular momentum coherent states: construction and time
evolution | 4 pages, RevTeX,(needs epsfig.sty). Presented on 6th International
Conference on Squeezed States and Uncertainty Relations, Napoli, 24-29 May
1999 | null | null | null | quant-ph | null | A family of angular momentum coherent states on the sphere is constructed
using previous work by Aragone et al [1]. These states depend on a complex
parameter which allows an arbitrary squeezing of the angular momentum
uncertainties. The time evolution of these states is analyzed assuming a rigid
body hamiltonian. The rich scenario of fractional revivals is exhibited with
cloning and many interference effects.
| [
{
"version": "v1",
"created": "Tue, 7 Sep 1999 15:47:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Arvieu",
"R.",
"",
"ISN, Grenoble, France"
],
[
"Rozmej",
"P.",
"",
"University MCS, Lublin,\n Poland"
]
] |
quant-ph/9909023 | Piotr Rozmej | M.Turek, P.Rozmej (University MCS, Lublin, Poland) and R. Arvieu (ISN,
Grenoble, France) | Spin-orbit pendulum - Relativistic extension | 4 pages, LaTeX2e (appolb.cls included). Presented at XXVI Mazurian
Lakes School of Physics on Nuclear Physics at the Turn of the Century,
Krzyze, Poland, September 1-11, 1999. To appear in Acta Phys. Polon. B (2000) | Acta Phys. Polon. B31 (2000) 517 | null | null | quant-ph | null | We discuss an extension of the theory of {\em spin-orbit pendulum} phenomenon
given in [1] to relativistic approach. It is done within the so called Dirac
Oscillator. Our first results, focusing on circular wave packet motion have
been published recently [2]. The scope of this paper is motion of a linear wave
packet. In relativistic approach we found {\em Zitterbewegung} in spin-orbit
motion (in Dirac representation) due to coupling to negative energy states.
This effect is washed out in the Foldy-Wouthuysen representation. Another
important change with respect to non-relativistic case is the loss of
periodicity. The phenomenon reminds the time evolution of population inversion
in Jaynes-Cummings model.
| [
{
"version": "v1",
"created": "Tue, 7 Sep 1999 17:40:29 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Turek",
"M.",
"",
"University MCS, Lublin, Poland"
],
[
"Rozmej",
"P.",
"",
"University MCS, Lublin, Poland"
],
[
"Arvieu",
"R.",
"",
"ISN,\n Grenoble, France"
]
] |
quant-ph/9909024 | Serguei Khlebnikov | S. Khlebnikov | Thermal fluctuations in macroscopic quantum memory | 9 pages, revtex, 2 figures; a minor correction for v2; small
corrections and some added details for v3 | null | null | PURD-TH-99-07 | quant-ph cond-mat.supr-con | null | We describe macroscopic quantum memory devices based on type-II toroidal
superconductors and estimate in one case and compute in another the rates at
which quantum information stored in these devices ``degrades'' because of
thermal fluctuations. In the case when the entire solid torus is
superconducting, the Boltzmann factor in the rate corresponds to a well-defined
critical fluctuation, and the rate is suppressed exponentially with the linear
size of the system. In the case when superconductivity is confined to the
surface of the torus, the rate is determined by diffusive motion of vortices
around the torus and does not depend exponentially on the linear size; we find,
however, that when the two dimensions of the torus are comparable the rate does
not contain the usual volume enhancement factor, i.e. it does not grow with the
total surface area of the sample. We describe a possible way to write to and
read from this quantum memory.
| [
{
"version": "v1",
"created": "Tue, 7 Sep 1999 22:51:17 GMT"
},
{
"version": "v2",
"created": "Mon, 27 Sep 1999 20:49:55 GMT"
},
{
"version": "v3",
"created": "Thu, 4 Nov 1999 21:33:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Khlebnikov",
"S.",
""
]
] |
quant-ph/9909025 | Toshihiko Ono | Toshihiko Ono | Structure behind Mechanics I: Foundation | 20 pages; trimmed | null | null | null | quant-ph | null | This paper proposes a basic theory on physical reality and a new foundation
for quantum mechanics and classical mechanics. It presents a scenario not only
to solve the problem of the arbitrariness on the operator ordering for the
quantization procedure, but also to clarify how the classical-limit occurs.
This paper is the first of the three papers into which the previous paper
quant-ph/9906130 has been separated for readability.
| [
{
"version": "v1",
"created": "Wed, 8 Sep 1999 17:49:29 GMT"
},
{
"version": "v2",
"created": "Thu, 9 Sep 1999 03:08:28 GMT"
},
{
"version": "v3",
"created": "Wed, 15 Sep 1999 04:07:36 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ono",
"Toshihiko",
""
]
] |
quant-ph/9909026 | Valerie Nowak | Stephen L. Adler and Lawrence P. Horwitz | Structure and Properties of Hughston's Stochastic Extension of the
Schr\"odinger Equation | Plain Tex, no figures | null | 10.1063/1.533255 | IASSNS-HEP-99-83 | quant-ph | null | Hughston has recently proposed a stochastic extension of the Schr\"odinger
equation, expressed as a stochastic differential equation on projective Hilbert
space. We derive new projective Hilbert space identities, which we use to give
a general proof that Hughston's equation leads to state vector collapse to
energy eigenstates, with collapse probabilities given by the quantum mechanical
probabilities computed from the initial state. We discuss the relation of
Hughston's equation to earlier work on norm-preserving stochastic equations,
and show that Hughston's equation can be written as a manifestly unitary
stochastic evolution equation for the pure state density matrix. We discuss the
behavior of systems constructed as direct products of independent subsystems,
and briefly address the question of whether an energy-based approach, such as
Hughston's, suffices to give an objective interpretation of the measurement
process in quantum mechanics.
| [
{
"version": "v1",
"created": "Wed, 8 Sep 1999 21:12:59 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Adler",
"Stephen L.",
""
],
[
"Horwitz",
"Lawrence P.",
""
]
] |
quant-ph/9909027 | Gennady Berman | G.P.Berman, G.D. Doolen, G.V. Lopez, and V.I. Tsifrinovich | Non-Resonant Effects in Implementation of Quantum Shor Algorithm | 11 pages, 13 figures | null | 10.1103/PhysRevA.61.042307 | null | quant-ph | null | We simulate Shor's algorithm on an Ising spin quantum computer. The influence
of non-resonant effects is analyzed in detail. It is shown that our ``$2\pi
k$''-method successfully suppresses non-resonant effects even for relatively
large values of the Rabi frequency.
| [
{
"version": "v1",
"created": "Wed, 8 Sep 1999 21:24:18 GMT"
},
{
"version": "v2",
"created": "Thu, 9 Sep 1999 00:14:39 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Berman",
"G. P.",
""
],
[
"Doolen",
"G. D.",
""
],
[
"Lopez",
"G. V.",
""
],
[
"Tsifrinovich",
"V. I.",
""
]
] |
quant-ph/9909028 | Viatcheslav V. Dobrovitski | M. I. Katsnelson, V. V. Dobrovitski, and B. N. Harmon | Propagation of local decohering action in distributed quantum systems | 6 REVTeX pages, no figures. Introduction and discussion sections are
extended | Phys. Rev. A 62, 022118 (July 2000) | 10.1103/PhysRevA.62.022118 | null | quant-ph | null | We study propagation of the decohering influence caused by a local
measurement performed on a distributed quantum system. As an example, the gas
of bosons forming a Bose-Einstein condensate is considered. We demonstrate that
the local decohering perturbation exerted on the measured region propagates
over the system in the form of a decoherence wave, whose dynamics is governed
by elementary excitations of the system. We argue that the post-measurement
evolution of the system (determined by elementary excitations) is of importance
for transfer of decoherence, while the initial collapse of the wave function
has negligible impact on the regions which are not directly affected by the
measurement.
| [
{
"version": "v1",
"created": "Thu, 9 Sep 1999 06:04:58 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Sep 1999 17:08:24 GMT"
},
{
"version": "v3",
"created": "Sun, 24 Sep 2000 08:06:02 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Katsnelson",
"M. I.",
""
],
[
"Dobrovitski",
"V. V.",
""
],
[
"Harmon",
"B. N.",
""
]
] |
quant-ph/9909029 | Massimiliano F. Sacchi | G. M. D'Ariano, M. F. Sacchi, R. Seno | Feedback-assisted measurement of the free mass position under the
Standard Quantum Limit | 18 pages, LaTeX with cimento.cls documentclass (included) | Nuovo Cimento B, {\bf 114}, 775 (1999) | null | null | quant-ph | null | The Standard Quantum Limit (SQL) for the measurement of a free mass position
is illustrated, along with two necessary conditions for breaching it. A
measurement scheme that overcomes the SQL is engineered. It can be achieved in
three-steps: i) a pre-squeezing stage; ii) a standard von Neumann measurement
with momentum-position object-probe interaction and iii) a feedback. Advantages
and limitations of this scheme are discussed. It is shown that all of the three
steps are needed in order to overcome the SQL. In particular, the von Neumann
interaction is crucial in getting the right state reduction, whereas other
experimentally achievable Hamiltonians, as, for example, the radiation-pressure
interaction, lead to state reductions that on the average cannot overcome the
SQL.
| [
{
"version": "v1",
"created": "Thu, 9 Sep 1999 10:14:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"D'Ariano",
"G. M.",
""
],
[
"Sacchi",
"M. F.",
""
],
[
"Seno",
"R.",
""
]
] |
quant-ph/9909030 | Margaret Reid | M. D. Reid | Quantum cryptography with a predetermined key, using continuous variable
Einstein-Podolsky-Rosen correlations | 11 pages,3 figures, changes are important,presented at QELS(May,2000)
San Francisco | Phys. Rev. A62,062308(2000) | 10.1103/PhysRevA.62.062308 | null | quant-ph | null | Correlations of the type discussed by EPR in their original 1935 paradox for
continuous variables exist for the quadrature phase amplitudes of two spatially
separated fields. These correlations were experimentally reported in 1992. We
propose to use such EPR beams in quantum cryptography, to transmit with high
efficiency messages in such a way that the receiver and sender may later
determine whether eavesdropping has occurred. The merit of the new proposal is
in the possibility of transmitting a reasonably secure yet predetermined key.
This would allow relay of a cryptographic key over long distances in the
presence of lossy channels.
| [
{
"version": "v1",
"created": "Thu, 9 Sep 1999 12:17:55 GMT"
},
{
"version": "v2",
"created": "Fri, 12 Jan 2001 08:27:22 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Reid",
"M. D.",
""
]
] |
quant-ph/9909031 | Mio Murao | Mio Murao, Martin B. Plenio and Vlatko Vedral | Quantum information distribution via entanglement | 15 pages, 3 figures | Phys. Rev. A 60, 032311 (2000) | 10.1103/PhysRevA.61.032311 | null | quant-ph | null | We present a generalization of quantum teleportation that distributes quantum
information from a sender's $d$-level particle to $N_o$ particles held by
remote receivers via an initially shared multiparticle entangled state. This
entangled state functions as a multiparty quantum information distribution
channel between the sender and the receivers. The structure of the distribution
channel determines how quantum information is processed. Our generalized
teleportation scheme allows multiple receivers at arbitrary locations, and can
be used for applications such as optimal quantum information broadcasting,
asymmetric telecloning, and quantum error correction.
| [
{
"version": "v1",
"created": "Thu, 9 Sep 1999 15:09:09 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Murao",
"Mio",
""
],
[
"Plenio",
"Martin B.",
""
],
[
"Vedral",
"Vlatko",
""
]
] |
quant-ph/9909032 | Dmitry Kamenev | G.P. Berman, G.D. Doolen, G.V.Lopez, and V.I. Tsifrinovich | Simulations of Quantum Logic Operations in Quantum Computer with Large
Number of Qubits | 13 pages, 15 figures | null | 10.1103/PhysRevA.61.062305 | null | quant-ph | null | We report the first simulations of the dynamics of quantum logic operations
with a large number of qubits (up to 1000). A nuclear spin chain in which
selective excitations of spins is provided by the gradient of the external
magnetic field is considered. The spins interact with their nearest neighbors.
We simulate the quantum control-not (CN) gate implementation for remote qubits
which provides the long-distance entanglement. Our approach can be applied to
any implementation of quantum logic gates involving a large number of qubits.
| [
{
"version": "v1",
"created": "Thu, 9 Sep 1999 18:06:20 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Berman",
"G. P.",
""
],
[
"Doolen",
"G. D.",
""
],
[
"Lopez",
"G. V.",
""
],
[
"Tsifrinovich",
"V. I.",
""
]
] |
quant-ph/9909033 | Dmitry Kamenev | G.P. Berman, G.D. Doolen, P.C. Hammel, and V.I. Tsifrinovich | Solid-State Nuclear Spin Quantum Computer Based on Magnetic Resonance
Force Microscopy | 16 pages, 5 figures | null | 10.1103/PhysRevB.61.14694 | null | quant-ph | null | We propose a nuclear spin quantum computer based on magnetic resonance force
microscopy (MRFM). It is shown that an MRFM single-electron spin measurement
provides three essential requirements for quantum computation in solids: (a)
preparation of the ground state, (b) one- and two- qubit quantum logic gates,
and (c) a measurement of the final state. The proposed quantum computer can
operate at temperatures up to 1K.
| [
{
"version": "v1",
"created": "Thu, 9 Sep 1999 20:42:08 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Berman",
"G. P.",
""
],
[
"Doolen",
"G. D.",
""
],
[
"Hammel",
"P. C.",
""
],
[
"Tsifrinovich",
"V. I.",
""
]
] |
quant-ph/9909034 | Zhaog | Gang Zhao | Explanation of Quantum Mechanics | LaTex,2 pages | null | null | null | quant-ph | null | By assuming that the kinetic energy,potential energy,momentum,and some other
physical quantities of a particle exist in the field out of the particle,the
Schrodinger equation is an equation describing field of a particle,but not the
particle itself.
| [
{
"version": "v1",
"created": "Fri, 10 Sep 1999 00:52:59 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zhao",
"Gang",
""
]
] |
quant-ph/9909035 | David Kielpinski | D. Kielpinski, B.E. King, C.J. Myatt, C.A. Sackett, Q.A. Turchette,
W.M. Itano, C. Monroe, D.J. Wineland, W.H. Zurek | Quantum Logic Using Sympathetically Cooled Ions | Submitted to Phys. Rev. A | null | null | null | quant-ph | null | One limit to the fidelity of quantum logic operations on trapped ions arises
from heating of the ions' collective modes of motion. Sympathetic cooling of
the ions during the logic operations may eliminate this source of errors. We
discuss benefits and drawbacks of this proposal, and describe possible
experimental implementations. We also present an overview of trapped-ion
dynamics in this scheme.
| [
{
"version": "v1",
"created": "Fri, 10 Sep 1999 01:06:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kielpinski",
"D.",
""
],
[
"King",
"B. E.",
""
],
[
"Myatt",
"C. J.",
""
],
[
"Sackett",
"C. A.",
""
],
[
"Turchette",
"Q. A.",
""
],
[
"Itano",
"W. M.",
""
],
[
"Monroe",
"C.",
""
],
[
"Wineland",
"D. J.",
""
],
[
"Zurek",
"W. H.",
""
]
] |
quant-ph/9909036 | M. H. Y. Moussa | N. G. de Almeida, C. J. Villas-Boas, E. Solano, and M. H. Y. Moussa | Reliable Teleportation of Ionic Motional States Through a Mapping
Process | null | null | null | null | quant-ph | null | We show how to teleport reliably an arbitrary superposition of n=0 and n=1
vibrational number state between two distant ions. This is done by first
mapping the vibrational state to be teleported into the internal degrees of
freedom of a given ion. Then we handle with the internal superposition state
following Bennett's original protocol and a recently proposed technique for
teleportation of ionic internal states [quant-ph/9903029]. Finally, the
teleportation of the vibrational state is achieved by reversing the mapping
process in the receiver ion. We remark that as in the teleportation of cavity
field and atomic states, the teleportation of vibrational states is 100%
successful for an ideal process.
| [
{
"version": "v1",
"created": "Fri, 10 Sep 1999 16:50:59 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"de Almeida",
"N. G.",
""
],
[
"Villas-Boas",
"C. J.",
""
],
[
"Solano",
"E.",
""
],
[
"Moussa",
"M. H. Y.",
""
]
] |
quant-ph/9909037 | Nicolas Cerf | N. J. Cerf (1,2), A. Ipe (1), X. Rottenberg (1) ((1) Universite Libre
de Bruxelles, (2) Jet Propulsion Laboratory, Caltech) | Universal cloning of continuous quantum variables | 4 pages, RevTex. Minor revisions, added explicit cloning
transformation, added references | Phys. Rev. Lett. 85 (2000) 1754 | 10.1103/PhysRevLett.85.1754 | null | quant-ph | null | The cloning of quantum variables with continuous spectra is analyzed. A
universal - or Gaussian - quantum cloning machine is exhibited that copies
equally well the states of two conjugate variables such as position and
momentum. It also duplicates all coherent states with a fidelity of 2/3. More
generally, the copies are shown to obey a no-cloning Heisenberg-like
uncertainty relation.
| [
{
"version": "v1",
"created": "Sat, 11 Sep 1999 00:00:34 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Oct 1999 19:06:13 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cerf",
"N. J.",
""
],
[
"Ipe",
"A.",
""
],
[
"Rottenberg",
"X.",
""
]
] |
quant-ph/9909038 | Ferdinand Schmidt-Kaler | Ch. Roos, Th. Zeiger, H. Rohde, H. C. Naegerl, J. Eschner, D.
Leibfried, F. Schmidt-Kaler, and R. Blatt (Institut fuer Experimentalphysik,
Universitaet Innsbruck, Austria) | Quantum state engineering on an optical transition and decoherence in a
Paul trap | 4 pages, 5 figures | null | 10.1103/PhysRevLett.83.4713 | null | quant-ph | null | A single Ca+ ion in a Paul trap has been cooled to the ground state of
vibration with up to 99.9% probability. Starting from this Fock state |n=0> we
have demonstrated coherent quantum state manipulation on an optical transition.
Up to 30 Rabi oscillations within 1.4 ms have been observed. We find a similar
number of Rabi oscillations after preparation of the ion in the |n=1> Fock
state. The coherence of optical state manipulation is only limited by laser and
ambient magnetic field fluctuations. Motional heating has been measured to be
as low as one vibrational quantum in 190 ms.
| [
{
"version": "v1",
"created": "Mon, 13 Sep 1999 10:04:19 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Roos",
"Ch.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
],
[
"Zeiger",
"Th.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
],
[
"Rohde",
"H.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
],
[
"Naegerl",
"H. C.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
],
[
"Eschner",
"J.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
],
[
"Leibfried",
"D.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
],
[
"Schmidt-Kaler",
"F.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
],
[
"Blatt",
"R.",
"",
"Institut fuer Experimentalphysik,\n Universitaet Innsbruck, Austria"
]
] |
quant-ph/9909039 | Robert R. Tucci | Robert R. Tucci | Quantum Information Theory - A Quantum Bayesian Net Perspective | 73 pages (files: 1 .tex, 3 .sty, 22 .eps) | null | null | null | quant-ph | null | The main goal of this paper is to give a pedagogical introduction to Quantum
Information Theory-to do this in a new way, using network diagrams called
Quantum Bayesian Nets. A lesser goal of the paper is to propose a few new
ideas, such as associating with each quantum Bayesian net a very useful density
matrix that we call the meta density matrix.
| [
{
"version": "v1",
"created": "Mon, 13 Sep 1999 13:59:48 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Tucci",
"Robert R.",
""
]
] |
quant-ph/9909040 | Stephen A. Fulling | G. Chen, S. A. Fulling, M. O. Scully | Grover's Algorithm for Multiobject Search in Quantum Computing | 11 pages, LaTeX; for proceedings of Jackson Hole Quantum Optics
Workshop in honor of Daniel Walls Corrections and minor revisions | null | null | null | quant-ph | null | L. K. Grover's search algorithm in quantum computing gives an optimal,
square-root speedup in the search for a single object in a large unsorted
database. In this paper, we expound Grover's algorithm in a Hilbert-space
framework that isolates its geometrical essence, and we generalize it to the
case where more than one object satisfies the search criterion.
| [
{
"version": "v1",
"created": "Mon, 13 Sep 1999 18:23:15 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Nov 1999 19:47:51 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chen",
"G.",
""
],
[
"Fulling",
"S. A.",
""
],
[
"Scully",
"M. O.",
""
]
] |
quant-ph/9909041 | Robert R. Tucci | Robert R. Tucci | Quantum Entanglement and Conditional Information Transmission | 32 pages (files: 1 .tex, 3 .sty, 8 .eps) | null | null | null | quant-ph | null | We propose a new measure of quantum entanglement. Our measure is defined in
terms of conditional information transmission for a Quantum Bayesian Net. We
show that our measure is identically equal to the Entanglement of Formation in
the case of a bipartite (two listener) system occupying a pure state. In the
case of mixed states, the relationship between these two measures is not known
yet. We discuss some properties of our measure. Our measure can be easily and
naturally generalized to handle n-partite (n-listener) systems. It is
non-negative for any n. It vanishes for conditionally separable states with n
listeners. It is symmetric under permutations of the n listeners. It decreases
if listeners are merged, pruned or removed. Most promising of all, it is
intimately connected with the Data Processing Inequalities. We also find a new
upper bound for classical mutual information which is of interest in its own
right.
| [
{
"version": "v1",
"created": "Mon, 13 Sep 1999 22:00:25 GMT"
},
{
"version": "v2",
"created": "Sun, 26 Sep 1999 04:14:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Tucci",
"Robert R.",
""
]
] |
quant-ph/9909042 | Mark Hillery | Bernard Yurke, Mark Hillery, and David Stoler | Position-momentum local realism violation of the Hardy type | 10 pages, no figures, to be published in Physical Review A | null | 10.1103/PhysRevA.60.3444 | null | quant-ph | null | We show that it is, in principle, possible to perform local realism violating
experiments of the Hardy type in which only position and momentum measurements
are made on two particles emanating from a common source. In the optical
domain, homodyne detection of the in-phase and out-of-phase amplitude
components of an electromagnetic field is analogous to position and momentum
measurement. Hence, local realism violations of the Hardy type are possible in
optical systems employing only homodyne detection.
| [
{
"version": "v1",
"created": "Tue, 14 Sep 1999 01:22:37 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Yurke",
"Bernard",
""
],
[
"Hillery",
"Mark",
""
],
[
"Stoler",
"David",
""
]
] |
quant-ph/9909043 | Paolo Facchi | P. Facchi and S. Pascazio | Spontaneous emission and lifetime modification caused by an intense
electromagnetic field | 25 pages, 6 figures | Phys. Rev. A 62, 023804 (2000). | 10.1103/PhysRevA.62.023804 | BA-TH/99-359 | quant-ph | null | We study the temporal evolution of a three-level system (such as an atom or a
molecule), initially prepared in an excited state, bathed in a laser field
tuned at the transition frequency of the other level. The features of the
spontaneous emission are investigated and the lifetime of the initial state is
evaluated: a Fermi "golden rule" still applies, but the on-shell matrix
elements depend on the intensity of the laser field. In general, the lifetime
is a decreasing function of the laser intensity. The phenomenon we discuss can
be viewed as an "inverse" quantum Zeno effect and can be analyzed in terms of
dressed states.
| [
{
"version": "v1",
"created": "Tue, 14 Sep 1999 15:29:10 GMT"
},
{
"version": "v2",
"created": "Thu, 25 Nov 1999 19:40:08 GMT"
},
{
"version": "v3",
"created": "Tue, 28 Mar 2000 17:19:31 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Facchi",
"P.",
""
],
[
"Pascazio",
"S.",
""
]
] |
quant-ph/9909044 | R. Simon | R. Simon | Peres-Horodecki separability criterion for continuous variable systems | 6 pages, no figures | null | 10.1103/PhysRevLett.84.2726 | null | quant-ph | null | The Peres-Horodecki criterion of positivity under partial transpose is
studied in the context of separability of bipartite continuous variable states.
The partial transpose operation admits, in the continuous case, a geometric
interpretation as mirror reflection in phase space. This recognition leads to
uncertainty principles, stronger than the traditional ones, to be obeyed by all
separable states. For all bipartite Gaussian states, the Peres-Horodecki
criterion turns out to be necessary and sufficient condition for separability.
| [
{
"version": "v1",
"created": "Tue, 14 Sep 1999 16:50:23 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Simon",
"R.",
""
]
] |
quant-ph/9909045 | Marcos C. de Oliveira | M. C. de Oliveira, S. S. Mizrahi and V. V. Dodonov | Information Transfer in the Course of a Quantum Interaction | 10 pages, 4 Postscript figures, to appear in J. Opt. B | J. Opt. B: Quantum Semiclassical Opt. 1, 610 (1999). | 10.1088/1464-4266/1/5/319 | null | quant-ph | null | We discuss the problem of the information transfer (exchange of states
configuration) between two interacting quantum systems along their evolution in
time. We consider the specific case of two modes of the electromagnetic field
with rotating wave coupling interaction (up-conversion in a nonlinear crystal).
We verify that for certain initial states of the fields the swapping of state
configuration occurs with conservation of the mean energy of each mode (without
energy transfer), characterising thus pure information flow.
| [
{
"version": "v1",
"created": "Wed, 15 Sep 1999 00:50:42 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"de Oliveira",
"M. C.",
""
],
[
"Mizrahi",
"S. S.",
""
],
[
"Dodonov",
"V. V.",
""
]
] |
quant-ph/9909046 | Dr Dagmar Bruss | D. Bruss, M. Cinchetti, G. M. D'Ariano and C. Macchiavello | Phase covariant quantum cloning | 9 pages, 1 figure | Phys. Rev. A 62, 12302 (2000) | 10.1103/PhysRevA.62.012302 | null | quant-ph | null | We consider an N -> M quantum cloning transformation acting on pure two-level
states lying on the equator of the Bloch sphere. An upper bound for its
fidelity is presented, by establishing a connection between optimal phase
covariant cloning and phase estimation. We give the explicit form of a cloning
transformation that achieves the bound for the case N=1, M=2, and find a link
between this case and optimal eavesdropping in the quantum cryptographic scheme
BB84.
| [
{
"version": "v1",
"created": "Wed, 15 Sep 1999 09:19:57 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Bruss",
"D.",
""
],
[
"Cinchetti",
"M.",
""
],
[
"D'Ariano",
"G. M.",
""
],
[
"Macchiavello",
"C.",
""
]
] |
quant-ph/9909047 | WD Heiss | W.D. Heiss | Repulsion of Resonance States and Exceptional Points | 4 pages, latex, 3 figures, to appear in Phys.Rev.E | null | 10.1103/PhysRevE.61.929 | null | quant-ph | null | Level repulsion is associated with exceptional points which are square root
singularities of the energies as functions of a (complex) interaction
parameter. This is also valid for resonance state energies. Using this concept
it is argued that level anti-crossing (crossing) must imply crossing
(anti-crossing) of the corresponding widths of the resonance states. Further,
itis shown that an encircling of an exceptional point induces a phase change of
one wave function but not of the other. An experimental setup is discussed
where this phase behaviour which differs from the one encountered at a diabolic
point can be observed.
| [
{
"version": "v1",
"created": "Wed, 15 Sep 1999 14:24:36 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Heiss",
"W. D.",
""
]
] |
quant-ph/9909048 | Chi-Yee Cheung | Chi-Yee Cheung | On the Possibility of Unconditionally Secure Quantum Bit Commitment | Withdrawn | null | null | null | quant-ph | null | This paper has been withdrawn by the author.
| [
{
"version": "v1",
"created": "Wed, 15 Sep 1999 15:50:00 GMT"
},
{
"version": "v2",
"created": "Wed, 6 Oct 1999 16:47:16 GMT"
},
{
"version": "v3",
"created": "Mon, 25 Oct 1999 21:40:18 GMT"
},
{
"version": "v4",
"created": "Mon, 10 Jul 2000 17:16:10 GMT"
},
{
"version": "v5",
"created": "Thu, 20 Dec 2001 18:21:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cheung",
"Chi-Yee",
""
]
] |
quant-ph/9909049 | Robert B. Griffiths | Robert B. Griffiths | Consistent histories, quantum truth functionals, and hidden variables | Latex 10 pages, no figures | Phys. Lett. A 265 (2000) pp. 12-19 | 10.1016/S0375-9601(99)00888-9 | null | quant-ph | null | A central principle of consistent histories quantum theory, the requirement
that quantum descriptions be based upon a single framework (or family), is
employed to show that there is no conflict between consistent histories and a
no-hidden-variables theorem of Bell, and Kochen and Specker, contrary to a
recent claim by Bassi and Ghirardi. The argument makes use of ``truth
functionals'' defined on a Boolean algebra of classical or quantum properties.
| [
{
"version": "v1",
"created": "Wed, 15 Sep 1999 19:48:23 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Griffiths",
"Robert B.",
""
]
] |
quant-ph/9909050 | De-Horng Lin | De-Hone Lin | Path Integral Solution by Sum Over Perturbation Series | 13 pages, ReVTeX, no figures | null | 10.1063/1.533266 | null | quant-ph | null | A method for calculating the relativistic path integral solution via sum over
perturbation series is given. As an application the exact path integral
solution of the relativistic Aharonov-Bohm-Coulomb system is obtained by the
method. Different from the earlier treatment based on the space-time
transformation and infinite multiple-valued trasformation of
Kustaanheimo-Stiefel in order to perform path integral, the method developed in
this contribution involves only the explicit form of a simple Green's function
and an explicit path integral is avoided.
| [
{
"version": "v1",
"created": "Thu, 16 Sep 1999 01:44:46 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Lin",
"De-Hone",
""
]
] |
quant-ph/9909051 | Andrea Rocco | A. Rocco, P. Grigolini | The Markov approximation revisited: Inconsistency of the standard
quantum Brownian motion model | 15 pages | Phys. Lett. A 252 (1999) 115-124 | 10.1016/S0375-9601(98)00940-2 | null | quant-ph cond-mat | null | We revisit the Markov approximation necessary to derive ordinary Brownian
motion from a model widely adopted in literature for this specific purpose. We
show that this leads to internal inconsistencies, thereby implying that further
search for a more satisfactory model is required.
| [
{
"version": "v1",
"created": "Thu, 16 Sep 1999 14:42:09 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Rocco",
"A.",
""
],
[
"Grigolini",
"P.",
""
]
] |
quant-ph/9909052 | Massimiliano F. Sacchi | K. Banaszek, G. M. D'Ariano, M. G. A. Paris, M. F. Sacchi | Maximum-likelihood estimation of the density matrix | 4 pages, 3 figures (5 eps files). Submitted to Phys. Rev. A as a
Rapid Communication | Phys. Rev. A 61, 010304(R) (2000). | 10.1103/PhysRevA.61.010304 | null | quant-ph | null | We present a universal technique for quantum state estimation based on the
maximum-likelihood method. This approach provides a positive definite estimate
for the density matrix from a sequence of measurements performed on identically
prepared copies of the system. The method is versatile and can be applied to
multimode radiation fields as well as to spin systems. The incorporation of
physical constraints, which is natural in the maximum-likelihood strategy,
leads to a substantial reduction of statistical errors. Numerical
implementation of the method is based on a particular form of the Gauss
decomposition for positive definite Hermitian matrices.
| [
{
"version": "v1",
"created": "Thu, 16 Sep 1999 17:22:43 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Banaszek",
"K.",
""
],
[
"D'Ariano",
"G. M.",
""
],
[
"Paris",
"M. G. A.",
""
],
[
"Sacchi",
"M. F.",
""
]
] |
quant-ph/9909053 | Nikolaj A. Ketsaris | A. A. Ketsaris | Generalized equation of relativistic quantum mechanics | 26 pages, no figures, uses revtex, submitted to Phys.Rev.D | null | null | null | quant-ph | null | We develop a new concept of quantum mechanics which is based on a generalized
space-time and on an action vector space similar to it. Both spaces are
provided by algebraic properties. This allows to calculate the Dirac matrixes
and to derive quantum mechanics equations from structure equations of the
specified algebras. A new interpretation of the wave function is given as
differential of the action vector. A generalization of the Dirac equation for
8-component wave function is derived. It is interpreted as the equation for two
leptons of the same generation. A procedure of the approximate description of
free leptons is formulated. The generalized equation of quantum mechanics is
reduced to the Dirac, Pauli and Schr\"odinger equations by the sequential use
of this procedure. We explain the existence of three lepton generations.
| [
{
"version": "v1",
"created": "Thu, 16 Sep 1999 18:49:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ketsaris",
"A. A.",
""
]
] |
quant-ph/9909054 | Yinqi Feng | Hongchen Fu, Yinqi Feng and A. I. Solomon | States interpolating between number and coherent states | 15 pages + 16 figures, Latex, submit to J. Phys. A: Math. Gen | null | null | null | quant-ph | null | The paper has been withdraw by authors
| [
{
"version": "v1",
"created": "Fri, 17 Sep 1999 12:17:09 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Mar 2000 18:52:14 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Fu",
"Hongchen",
""
],
[
"Feng",
"Yinqi",
""
],
[
"Solomon",
"A. I.",
""
]
] |
quant-ph/9909055 | Yinqi Feng | Hongchen Fu, Yinqi Feng and A. I. Solomon | States interpolating between number and coherent states and their
interaction with atomic systems | 26 pages, 29 EPS figures, Latex, Accepted for publication in J.Phys.A | null | 10.1088/0305-4470/33/11/306 | null | quant-ph | null | Using the eigenvalue definition of binomial states we construct new
intermediate number-coherent states which reduce to number and coherent states
in two different limits. We reveal the connection of these intermediate states
with photon-added coherent states and investigate their non-classical
properties and quasi-probability distributions in detail. It is of interest to
note that these new states, which interpolate between coherent states and
number states, neither of which exhibit squeezing, are nevertheless squeezed
states. A scheme to produce these states is proposed. We also study the
interaction of these states with atomic systems in the framework of the
two-photon Jaynes-Cummings model, and describe the response of the atomic
system as it varies between the pure Rabi oscillation and the collapse-revival
mode and investigate field observables such as photon number distribution,
entropy and the Q-function.
| [
{
"version": "v1",
"created": "Fri, 17 Sep 1999 12:28:26 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Mar 2000 17:06:32 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Fu",
"Hongchen",
""
],
[
"Feng",
"Yinqi",
""
],
[
"Solomon",
"A. I.",
""
]
] |
quant-ph/9909056 | A. P. Balachandran | A.P.Balachandran and S.M.Roy | A Quantum Anti-Zeno Paradox | 10 pages,latex | Phys.Rev.Lett.84:4019-4022,2000 | 10.1103/PhysRevLett.84.4019 | SU-4240-703,TIFR/TH/99-24 | quant-ph gr-qc hep-th | null | We establish an exact differential equation for the operator describing
time-dependent measurements continuous in time and obtain a series solution.
Suppose the projection operator $E(t) = U(t) E U^\dagger(t)$ is measured
continuously from t = 0 to T, where E is a projector leaving the initial state
unchanged and U(t) a unitary operator obeying U(0) = 1 and some smoothness
conditions in t. We prove that the probability of always finding E(t) = 1 from
t = 0 to T is unity. If $U(t) \neq 1$, the watched kettle is sure to `boil'.
| [
{
"version": "v1",
"created": "Fri, 17 Sep 1999 19:18:08 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Balachandran",
"A. P.",
""
],
[
"Roy",
"S. M.",
""
]
] |
quant-ph/9909057 | Antonio Vidiella-Barranco | A. Vidiella-Barranco (Universidade Estadual de Campinas, Brazil) | Entanglement and nonextensive statistics | 8 pages, LaTex, 4 figures | Phys. Lett A, 260, 335 (1999) | 10.1016/S0375-9601(99)00551-4 | null | quant-ph | null | It is presented a generalization of the von Neumann mutual information in the
context of Tsallis' nonextensive statistics. As an example, entanglement
between two (two-level) quantum subsystems is discussed. Important changes
occur in the generalized mutual information, which measures the degree of
entanglement, depending on the entropic index q.
| [
{
"version": "v1",
"created": "Fri, 17 Sep 1999 19:19:17 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Vidiella-Barranco",
"A.",
"",
"Universidade Estadual de Campinas, Brazil"
]
] |
quant-ph/9909058 | Dr. Daniel A. Lidar | Dave Bacon, Julia Kempe, Daniel A. Lidar, and K.B. Whaley (UC
Berkeley) | Universal Fault-Tolerant Computation on Decoherence-Free Subspaces | 5 pages, no figures. Many small changes and clarifications. Expanded
discussion of relevance to solid-state implementations. This version to
appear in Phys. Rev. Lett | Phys. Rev. Lett. Vol 85 (8), p. 1758-61 (2000) | 10.1103/PhysRevLett.85.1758 | null | quant-ph | null | A general scheme to perform universal quantum computation within
decoherence-free subspaces (DFSs) of a system's Hilbert space is presented.
This scheme leads to the first fault-tolerant realization of universal quantum
computation on DFSs with the properties that (i) only one- and two-qubit
interactions are required, and (ii) the system remains within the DFS
throughout the entire implementation of a quantum gate. We show explicitly how
to perform universal computation on clusters of the four-qubit DFS encoding one
logical qubit each under "collective decoherence" (qubit-permutation-invariant
system-bath coupling). Our results have immediate relevance to a number of
solid-state quantum computer implementations, in particular those in which
quantum logic is implemented through exchange interactions, such as the
recently proposed spin-spin coupled GaAs quantum dot arrays and the Si:$^{31}$P
nuclear spin arrays.
| [
{
"version": "v1",
"created": "Sat, 18 Sep 1999 00:26:31 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Jun 2000 19:00:48 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Bacon",
"Dave",
"",
"UC\n Berkeley"
],
[
"Kempe",
"Julia",
"",
"UC\n Berkeley"
],
[
"Lidar",
"Daniel A.",
"",
"UC\n Berkeley"
],
[
"Whaley",
"K. B.",
"",
"UC\n Berkeley"
]
] |
quant-ph/9909059 | Howard M. Wiseman | Jin Wang, H.M. Wiseman, and Z.Ficek | Quantum interference in the fluorescence of a molecular system | 11 pages, including 8 figures | null | 10.1103/PhysRevA.62.013818 | null | quant-ph | null | It has been observed experimentally [H.R. Xia, C.Y. Ye, and S.Y. Zhu, Phys.
Rev. Lett. {\bf 77}, 1032 (1996)] that quantum interference between two
molecular transitions can lead to a suppression or enhancement of spontaneous
emission. This is manifested in the fluorescent intensity as a function of the
detuning of the driving field from the two-photon resonance condition. Here we
present a theory which explains the observed variation of the number of peaks
with the mutual polarization of the molecular transition dipole moments. Using
master equation techniques we calculate analytically as well as numerically the
steady-state fluorescence, and find that the number of peaks depends on the
excitation process. If the molecule is driven to the upper levels by a
two-photon process, the fluorescent intensity consists of two peaks regardless
of the mutual polarization of the transition dipole moments. If the excitation
process is composed of both a two-step one-photon process and a one-step,
two-photon process, then there are two peaks on transitions with parallel
dipole moments and three peaks on transitions with antiparallel dipole moments.
This latter case is in excellent agreement with the experiment.
| [
{
"version": "v1",
"created": "Mon, 20 Sep 1999 03:29:43 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Wang",
"Jin",
""
],
[
"Wiseman",
"H. M.",
""
],
[
"Ficek",
"Z.",
""
]
] |
quant-ph/9909060 | Armin Uhlmann | Armin Uhlmann | Fidelity and Concurrence of conjugated states | 10 pages, RevTex, Correction: Enlarged, reorganized version. More
explanations | Phys. Rev. A, 62, 032307 (2000) | 10.1103/PhysRevA.62.032307 | null | quant-ph math-ph math.MP | null | We prove some new properties of fidelity (transition probability) and
concurrence, the latter defined by straightforward extension of Wootters
notation. Choose a conjugation and consider the dependence of fidelity or of
concurrence on conjugated pairs of density operators. These functions turn out
to be concave or convex roofs. Optimal decompositions are constructed. Some
applications to two- and tripartite systems illustrate the general theorem.
| [
{
"version": "v1",
"created": "Mon, 20 Sep 1999 09:06:48 GMT"
},
{
"version": "v2",
"created": "Sun, 10 Oct 1999 12:46:14 GMT"
},
{
"version": "v3",
"created": "Sat, 4 Dec 1999 14:50:40 GMT"
},
{
"version": "v4",
"created": "Fri, 7 Jul 2000 09:00:46 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Uhlmann",
"Armin",
""
]
] |
quant-ph/9909061 | Nikolay Vitanov | R. G. Unanyan, N. V. Vitanov, B. W. Shore, and K. Bergmann | Coherent properties of a tripod system coupled via a continuum | 9 pages, 4 figures, twocolumn revtex style. Copies with figures of
better quality available upon request | null | 10.1103/PhysRevA.61.043408 | null | quant-ph | null | We present results from a study of the coherence properties of a system
involving three discrete states coupled to each other by two-photon processes
via a common continuum. This tripod linkage is an extension of the standard
laser-induced continuum structure (LICS) which involves two discrete states and
two lasers. We show that in the tripod scheme, there exist two population
trapping conditions; in some cases these conditions are easier to satisfy than
the single trapping condition in two-state LICS. Depending on the pulse timing,
various effects can be observed. We derive some basic properties of the tripod
scheme, such as the solution for coincident pulses, the behaviour of the system
in the adiabatic limit for delayed pulses, the conditions for no ionization and
for maximal ionization, and the optimal conditions for population transfer
between the discrete states via the continuum. In the case when one of the
discrete states is strongly coupled to the continuum, the population dynamics
reduces to a standard two-state LICS problem (involving the other two states)
with modified parameters; this provides the opportunity to customize the
parameters of a given two-state LICS system.
| [
{
"version": "v1",
"created": "Mon, 20 Sep 1999 11:47:23 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Unanyan",
"R. G.",
""
],
[
"Vitanov",
"N. V.",
""
],
[
"Shore",
"B. W.",
""
],
[
"Bergmann",
"K.",
""
]
] |
quant-ph/9909062 | Paul Slater | Paul B. Slater (University of California) | Essentially All Gaussian Two-Party Quantum States are a priori
Nonclassical but Classically Correlated | Seven pages, one table. Expanded introduction, additional references
included | J. Opt. B: Quantum Semiclass. Opt. 2 (2000) L19-L24 | 10.1088/1464-4266/2/4/101 | null | quant-ph | null | Duan, Giedke, Cirac and Zoller (quant-ph/9908056) and, independently, Simon
(quant-ph/9909044) have recently found necessary and sufficient conditions for
the separability (classical correlation) of the Gaussian two-party (continuous
variable) states. Duan et al remark that their criterion is based on a "much
stronger bound" on the total variance of a pair of Einstein-Podolsky-Rosen-type
operators than is required simply by the uncertainty relation. Here, we seek to
formalize and test this particular assertion in both classical and
quantum-theoretic frameworks. We first attach to these states the classical a
priori probability (Jeffreys' prior), proportional to the volume element of the
Fisher information metric on the Riemannian manifold of Gaussian (quadrivariate
normal) probability distributions. Then, numerical evidence indicates that more
than ninety-nine percent of the Gaussian two-party states do, in fact, meet the
more stringent criterion for separability. We collaterally note that the prior
probability assigned to the classical states, that is those having positive
Glauber-Sudarshan P-representations, is less than one-thousandth of one
percent. We, then, seek to attach as a measure to the Gaussian two-party
states, the volume element of the associated (quantum-theoretic) Bures (minimal
monotone) metric. Our several extensive analyses, then, persistently yield
probabilities of separability and classicality that are, to very high orders of
accuracy, unity and zero, respectively, so the two apparently quite distinct
(classical and quantum-theoretic) forms of analysis are rather remarkably
consistent in their findings.
| [
{
"version": "v1",
"created": "Mon, 20 Sep 1999 22:01:22 GMT"
},
{
"version": "v2",
"created": "Mon, 18 Oct 1999 18:09:02 GMT"
},
{
"version": "v3",
"created": "Wed, 10 Nov 1999 19:01:05 GMT"
},
{
"version": "v4",
"created": "Tue, 21 Mar 2000 22:23:53 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Slater",
"Paul B.",
"",
"University of California"
]
] |
quant-ph/9909063 | Alexander Elgart | J. E. Avron and A. Elgart | Smooth adiabatic evolutions with leaky power tails | Final form, to appear in J. Phys. A; 11 pages, no figures | null | 10.1088/0305-4470/32/50/102 | null | quant-ph math-ph math.MP physics.atom-ph | null | Adiabatic evolutions with a gap condition have, under a range of
circumstances, exponentially small tails that describe the leaking out of the
spectral subspace. Adiabatic evolutions without a gap condition do not seem to
have this feature in general. This is a known fact for eigenvalue crossing. We
show that this is also the case for eigenvalues at the threshold of the
continuous spectrum by considering the Friedrichs model.
| [
{
"version": "v1",
"created": "Tue, 21 Sep 1999 08:58:14 GMT"
},
{
"version": "v2",
"created": "Mon, 8 Nov 1999 10:05:39 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Avron",
"J. E.",
""
],
[
"Elgart",
"A.",
""
]
] |
quant-ph/9909064 | Pinaki Roy | B.Roy and P.Roy | Time dependent nonclassical properties of even and odd nonlinear
coherent states | 3 eps figures | null | 10.1016/S0375-9601(99)00693-3 | null | quant-ph | null | We construct even and odd nonlinear coherent states of a parametric
oscillator and examine their nonclassical properties.It has been shown that
these superpositions exhibit squeezing and photon antibunching which change
with time.
| [
{
"version": "v1",
"created": "Tue, 21 Sep 1999 11:05:43 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Roy",
"B.",
""
],
[
"Roy",
"P.",
""
]
] |
quant-ph/9909065 | Marcel Reginatto | Marcel Reginatto | Hydrodynamical formulation of quantum mechanics, Kahler structure, and
Fisher information | 17 pages, no figures | null | null | null | quant-ph | null | The Schrodinger equation can be derived using the minimum Fisher information
principle. I discuss why such an approach should work, and also show that the
Kahler and Hilbert space structures of quantum mechanics result from combining
the symplectic structure of the hydrodynamical model with the Fisher
information metric.
| [
{
"version": "v1",
"created": "Tue, 21 Sep 1999 15:18:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Reginatto",
"Marcel",
""
]
] |
quant-ph/9909066 | John Grondalski | John P. Grondalski, Paul M. Alsing, Ivan H. Deutsch | Spatial Correlation Diagnostics for Atoms in Optical Lattices | 13 pages, 6 figures | "Spatial correlation diagnostics for atoms in optical lattices",
J. Grondalski, I. H. Deutsch, and P. M. Alsing, Opt. Exp. vol. 5, 249 (1999),
Direct link to Journal: http://epubs.osa.org/oearchive/pdf/12687.pdf | 10.1364/OE.5.000249 | null | quant-ph | null | We explore the use of first and second order same-time atomic spatial
correlation functions as a diagnostic for probing the small scale spatial
structure of atomic samples trapped in optical lattices. Assuming an ensemble
of equivalent atoms, properties of the local wave function at a given lattice
site can be measured using same-position first-order correlations. Statistics
of atomic distributions over the lattice can be measured via two-point
correlations, generally requiring the averaging of multiple realizations of
statistically similar but distinct realizations in order to obtain sufficient
signal to noise. Whereas two-point first order correlations are fragile due to
phase fluctuations from shot-to-shot in the ensemble, second order correlations
are robust. We perform numerical simulations to demonstrate these diagnostic
tools.
| [
{
"version": "v1",
"created": "Tue, 21 Sep 1999 17:07:46 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Aug 2000 02:37:40 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Grondalski",
"John P.",
""
],
[
"Alsing",
"Paul M.",
""
],
[
"Deutsch",
"Ivan H.",
""
]
] |
quant-ph/9909067 | Arvind | Arvind (GNDU. Amritsar) and Kavita Dorai (IISc. Bangalore) and Anil
Kumar (IISc. Bangalore) | Quantum entanglement in the NMR implementation of the Deutsch-Jozsa
algorithm | 4-pages in revtex with 5 eps figure included using psfig | Pramana Jr. of Physics 56, L705-L713 (2001) | 10.1007/s12043-001-0095-8 | null | quant-ph | null | A scheme to execute an n-bit Deutsch-Jozsa (D-J) algorithm using n qubits has
been implemented for up to three qubits on an NMR quantum computer. For the one
and two bit Deutsch problem, the qubits do not get entangled, hence the NMR
implementation is achieved without using spin-spin interactions. It is for the
three bit case, that the manipulation of entangled states becomes essential.
The interactions through scalar J-couplings in NMR spin systems have been
exploited to implement entangling transformations required for the three bit
D-J algorithm.
| [
{
"version": "v1",
"created": "Wed, 22 Sep 1999 08:34:48 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Arvind",
"",
"",
"GNDU. Amritsar"
],
[
"Dorai",
"Kavita",
"",
"IISc. Bangalore"
],
[
"Kumar",
"Anil",
"",
"IISc. Bangalore"
]
] |
quant-ph/9909068 | Miloslav Znojil | Miloslav Znojil | Short-range oscillators in power-series picture | 23 pages, latex, submitted to J. Phys. A: Math. Gen | J. Phys. A: Math. Gen. 33 (2000) 1647-59 | 10.1088/0305-4470/33/8/309 | null | quant-ph | null | A class of short-range potentials on the line is considered as an
asymptotically vanishing phenomenological alternative to the popular confining
polynomials. We propose a method which parallels the analytic Hill-Taylor
description of anharmonic oscillators and represents all our Jost solutions
non-numerically, in terms of certain infinite hypergeometric-like series. In
this way the well known solvable Rosen-Morse and scarf models are generalized.
| [
{
"version": "v1",
"created": "Wed, 22 Sep 1999 16:10:28 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Znojil",
"Miloslav",
""
]
] |
quant-ph/9909069 | P. Narayana Swamy | P. Narayana Swamy | q-Deformed Boson Oscillators and Zero Point Energy | 9 pages | Int. J. Mod. Phys. B12, 3495 (1998) | null | null | quant-ph | null | Just as for the ordinary quantum harmonic oscillators, we expect the
zero-point energy to play a crucial role in the correct high temperature
behavior. We accordingly reformulate the theory of the statistical distribution
function for the q-deformed boson oscillators and develop an approximate theory
incorporating the zero-point energy. We are then able to demonstrate that for
small deformations, the theory reproduces the correct limits both for very high
temperatures and for very low temperatures. The deformed theory thus reduces to
the undeformed theory in these extreme cases.
| [
{
"version": "v1",
"created": "Wed, 22 Sep 1999 16:32:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Swamy",
"P. Narayana",
""
]
] |
quant-ph/9909070 | David Collins | G. D. Sanders, K. W. Kim, and W. C. Holton | An optically driven quantum dot quantum computer | 4 figures | null | 10.1103/PhysRevA.60.4146 | null | quant-ph | null | We propose a quantum computer structure based on coupled asymmetric
single-electron quantum dots. Adjacent dots are strongly coupled by means of
electric dipole-dipole interactions enabling rapid computation rates. Further,
the asymmetric structures can be tailored for a long coherence time. The result
maximizes the number of computation cycles prior to loss of coherence.
| [
{
"version": "v1",
"created": "Wed, 22 Sep 1999 21:50:54 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Sanders",
"G. D.",
""
],
[
"Kim",
"K. W.",
""
],
[
"Holton",
"W. C.",
""
]
] |
quant-ph/9909071 | Robert Clifton | Rob Clifton (Department of Philosophy, Department of History and
Philosophy of Science, University of Pittsburgh), Bradley Monton (Department
of Philosophy, Princeton University) | Counting Marbles with 'Accessible' Mass Density: A Reply to Bassi and
Ghirardi | 14 pages, TeX, submitted to The British Journal for Philosophy of
Science | null | null | null | quant-ph | null | In a previous article (cf. quant-ph/9905065) we argued that, while Lewis is
correct that the enumeration principle fails in dynamical wavepacket reduction
theories, one need not following Lewis in rejecting these theories. Because the
dynamical reduction process itself prevents the failure of enumeration from
ever becoming manifest, and because one can treat the semantics for dynamical
reduction theories as not adding anything of ontological import to them, it is
reasonable to accept these theories notwithstanding Lewis's counting anomaly.
In their response to our paper (cf. quant-ph/9907050), Bassi and Ghirardi
reject our criticisms of their own response to Lewis, as well as our argument
against Lewis that dynamical reduction precludes failures of enumeration from
ever becoming manifest. Our intention here is to demonstrate that Bassi and
Ghirardi's responses to us do not succeed.
| [
{
"version": "v1",
"created": "Thu, 23 Sep 1999 01:24:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Clifton",
"Rob",
"",
"Department of Philosophy, Department of History and\n Philosophy of Science, University of Pittsburgh"
],
[
"Monton",
"Bradley",
"",
"Department\n of Philosophy, Princeton University"
]
] |
quant-ph/9909072 | Lev Vaidman | Y. Aharonov and L. Vaidman | Nonlocal Aspects of a Quantum Wave | 12 pages | null | 10.1103/PhysRevA.61.052108 | null | quant-ph hep-th | null | Various aspects of nonlocality of a quantum wave are discussed. In
particular, the question of the possibility of extracting information about the
relative phase in a quantum wave is analyzed. It is argued that there is a
profound difference in the nonlocal properties of the quantum wave between
fermion and boson particles. The phase of the boson quantum state can be found
from correlations between results of measurements in separate regions. These
correlations are identical to the Einstein-Podolsky-Rosen (EPR) correlations
between two entangled systems. An ensemble of results of measurements performed
on fermion quantum waves does not exhibit the EPR correlations and the relative
phase of fermion quantum waves cannot be found from these results. The
existence of a physical variable (the relative phase) which cannot be measured
locally is the nonlocality aspect of the quantum wave of a fermion.
| [
{
"version": "v1",
"created": "Thu, 23 Sep 1999 12:49:29 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Aharonov",
"Y.",
""
],
[
"Vaidman",
"L.",
""
]
] |
quant-ph/9909073 | Paul Busch | P. Busch (Hull, UK) | Quantum states and generalized observables: a simple proof of Gleason's
theorem | 3 pages, revtex. New title, and presentation substantially revised,
focus now being on the characterization of probability measures on the set of
effects rather than the question of hidden variables | Phys. Rev. Lett. 91, 120403 (2003) | 10.1103/PhysRevLett.91.120403 | null | quant-ph | null | A quantum state can be understood in a loose sense as a map that assigns a
value to every observable. Formalizing this characterization of states in terms
of generalized probability distributions on the set of effects, we obtain a
simple proof of the result, analogous to Gleason's theorem, that any quantum
state is given by a density operator. As a corollary we obtain a von
Neumann-type argument against non-contextual hidden variables. It follows that
on an individual interpretation of quantum mechanics, the values of effects are
appropriately understood as propensities.
| [
{
"version": "v1",
"created": "Thu, 23 Sep 1999 13:57:31 GMT"
},
{
"version": "v2",
"created": "Sat, 26 May 2001 00:02:36 GMT"
},
{
"version": "v3",
"created": "Wed, 28 May 2003 20:09:22 GMT"
}
] | 2011-01-04T00:00:00 | [
[
"Busch",
"P.",
"",
"Hull, UK"
]
] |
quant-ph/9909074 | Dima Shepelyansky | B. Georgeot and D. L. Shepelyansky (CNRS, Toulouse) | Quantum Chaos Border for Quantum Computing | revtex, 4 pages, 5 figures, more details and data added | null | 10.1103/PhysRevE.62.3504 | null | quant-ph chao-dyn cond-mat nlin.CD | null | We study a generic model of quantum computer, composed of many qubits coupled
by short-range interaction. Above a critical interqubit coupling strength,
quantum chaos sets in, leading to quantum ergodicity of the computer
eigenstates. In this regime the noninteracting qubit structure disappears, the
eigenstates become complex and the operability of the computer is destroyed.
Despite the fact that the spacing between multi-qubit states drops
exponentially with the number of qubits $n$, we show that the quantum chaos
border decreases only linearly with $n$. This opens a broad parameter region
where the efficient operation of a quantum computer remains possible.
| [
{
"version": "v1",
"created": "Thu, 23 Sep 1999 16:43:39 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Oct 1999 16:50:45 GMT"
},
{
"version": "v3",
"created": "Mon, 17 Jan 2000 11:54:39 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Georgeot",
"B.",
"",
"CNRS, Toulouse"
],
[
"Shepelyansky",
"D. L.",
"",
"CNRS, Toulouse"
]
] |
quant-ph/9909075 | Matteo G. A. Paris | Matteo G A Paris | Optical qubit by conditional interferometry | RevTeX, 4 pictures (6 ps-files). Web contact at
http://enterprise.pv.infn.it/~paris | Phys. Rev. A. vol 62, 033813 (2000) | 10.1103/PhysRevA.62.033813 | null | quant-ph | null | We suggest a method to prepare any chosen superposition a0 |0> + a1 |1> of
the vacuum and one-photon states. The method is based on a conditional
double-interferometer fed by an one-photon state and a coherent state. The
scheme involves only linear optical elements and avalanche photodetectors, and
therefore it should be realizable with current technology. A realistic
description of the triggering photodetectors is employed, i.e. we assume that
they can only check, with a certain efficiency, whether or not any photon is
present. We discuss two working regimes, and show that output states with
fidelity arbitrarily close to unit may be obtained, with non vanishing
conditional probability, also for low quantum efficiency at the photodetectors.
| [
{
"version": "v1",
"created": "Fri, 24 Sep 1999 11:40:14 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Paris",
"Matteo G A",
""
]
] |
quant-ph/9909076 | Valerie Nowak | Stephen L. Adler | Derivation of the Lindblad Generator Structure by use of the It\^o
Stochastic Calculus | Plain TEX, no figures or tables | null | 10.1016/S0375-9601(99)00847-6 | IASSNS-HEP-99/85 | quant-ph | null | We use the It\^o stochastic calculus to give a simple derivation of the
Lindblad form for the generator of a completely positive density matrix
evolution, by specialization from the corresponding global form for a
completely positive map. As a by-product, we obtain a generalized generator for
a completely positive stochastic density matrix evolution.
| [
{
"version": "v1",
"created": "Fri, 24 Sep 1999 20:31:44 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Adler",
"Stephen L.",
""
]
] |
quant-ph/9909077 | C. Y. Chen | Changye Chen | Legitimacy of wave-function expansion | 8 pages, 0 figure | null | null | null | quant-ph | null | In this letter we investigate the common procedure in which any wave function
is expanded into a series of eigenfunctions. It is shown that as far as
dynamical systems are concerned the expanding procedure involves various
mathematical and physical difficulties. With or without introducing phase
factors, such expansions do not represent dynamical wave functions.
| [
{
"version": "v1",
"created": "Sat, 25 Sep 1999 03:44:44 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chen",
"Changye",
""
]
] |
quant-ph/9909078 | Robert A. Herrmann | Robert A. Herrmann | The Encoding of Quantum State Information Within Subparticles | Plain Tex, 6 pages. In this version, significant uniqueness
statements are added | null | null | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A method is given by which the descriptive content of quantum state
information can be encoded into subparticle coordinates. This method is
consistent with the MA-model solution to the general grand unification problem.
Subparticle mechanisms via affine or linear transformations are also discussed.
| [
{
"version": "v1",
"created": "Sat, 25 Sep 1999 15:04:14 GMT"
},
{
"version": "v2",
"created": "Mon, 21 Feb 2005 19:28:04 GMT"
},
{
"version": "v3",
"created": "Fri, 8 Jul 2005 13:31:30 GMT"
},
{
"version": "v4",
"created": "Wed, 29 Mar 2006 15:51:55 GMT"
},
{
"version": "v5",
"created": "Sun, 6 Jan 2008 12:38:53 GMT"
},
{
"version": "v6",
"created": "Sat, 20 Dec 2008 14:16:44 GMT"
},
{
"version": "v7",
"created": "Mon, 22 Nov 2010 14:32:31 GMT"
}
] | 2010-11-23T00:00:00 | [
[
"Herrmann",
"Robert A.",
""
]
] |
quant-ph/9909079 | Alexander D. Panov | Alexander D. Panov | General equation for Zeno-like effects in spontaneous exponential decay | LaTeX 2.09 file, 11 pages, no figures. Accepted in Physics Letters A | Physics Letters A, V.260, No 6 (1999), P. 441-446 | 10.1016/S0375-9601(99)00570-8 | null | quant-ph | null | It was shown that different mechanisms of perturbation of spontaneous decay
constant: inelastic interaction of emitted particles with particle detector,
decay onto an unstable level, Rabi transition from the final state of decay
(electromagnetic field domination) and some others are really the special kinds
of one general effect - perturbation of decay constant by dissipation of the
final state of decay. Such phenomena are considered to be Zeno-like effects and
general formula for perturbed decay constant is deduced.
| [
{
"version": "v1",
"created": "Sun, 26 Sep 1999 09:37:23 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Panov",
"Alexander D.",
""
]
] |
quant-ph/9909080 | Arnold Neumaier | Arnold Neumaier | Noncommutative analysis and quantum physics I. States and ensembles | 38 pages | null | null | null | quant-ph gr-qc | null | In this sequence of papers, noncommutative analysis is used to give a
consistent axiomatic approach to a unified conceptual foundation of classical
and quantum physics.
The present Part I defines the concepts of observables, states and ensembles,
clarifies the logical relations and operations for them, and shows how they
give rise to dynamics and probabilities.
States are identified with maximal consistent sets of weak equalities in the
algebra of observables (instead of, as usual, with the rays in a Hilbert
space). This leads to a concise foundation of quantum mechanics, free of
undefined terms, separating in a clear way the deterministic and the stochastic
features of quantum physics.
The traditional postulates of quantum mechanics are derived from
well-motivated axiomatic assumptions. No special quantum logic is needed to
handle the peculiarities of quantum mechanics. Foundational problems associated
with the measurement process, such as the reduction of the state vector,
disappear.
The new interpretation of quantum mechanics contains `elements of physical
reality' without the need to introduce a classical framework with hidden
variables. In particular, one may talk about the state of the universe without
the need of an external observer and without the need to assume the existence
of multiple universes.
| [
{
"version": "v1",
"created": "Sun, 26 Sep 1999 15:01:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Neumaier",
"Arnold",
""
]
] |
quant-ph/9909081 | Hani Kaldass | A. Bohm and H. Kaldass | Rigged Hilbert Space Resonances and Time Asymmetric Quantum Mechanics | 17 pages | null | null | null | quant-ph math-ph math.MP | null | The Rigged Hilbert Space (RHS) theory of resonance scattering and decay is
reviewed and contrasted with the standard Hilbert space (HS) theory of quantum
mechanics. The main difference is in the choice of boundary conditions. Whereas
the conventional theory allows for the in-states $\phi^+$ and the out-states
(observables) $\psi^-$ of the S-matrix elements $(\psi^-,\phi^+)=(\psi^{out},S
\phi^{in})$ any elements of the HS $\H$, $\{\psi^-\}=\{\phi^+\}(=\H)$, the RHS
theory chooses the boundary conditions~:
$\phi^+\in\Phi_-\subset\H\subset\Phi_-^\times$, $\psi^-\in\Phi_+\subset
\H\subset \Phi_+^\times$, where $\Phi_-$ ($\Phi_+$) are Hardy class spaces
associated to the lower (upper) half-plane of the second sheet of the
analytically continued S-matrix. This can be phenomenologically justified by
causality. The two RHS's for states $\phi^+$ and observables $\psi^-$ provide
new vectors which are not in $\H$, e.g. the Dirac-Lippmann-Schwinger kets
$|E^{\pm}\in\Phi_{\mp}^{\times}$ (solutions of the Lippmann-Schwinger equation
with $\pm i\epsilon$ respectively) and the Gamow vectors
$|E_R-i\Gamma/2^\pm\in\Phi_{\mp}^\times$. The Gamow vectors $|E_R-i\Gamma/2^-$
have all the properties that one heuristically needs for quasistable states. In
addition, they give rise to asymmetric time evolution expressing
irreversibility on the microphysical level.
| [
{
"version": "v1",
"created": "Mon, 27 Sep 1999 03:05:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bohm",
"A.",
""
],
[
"Kaldass",
"H.",
""
]
] |
quant-ph/9909082 | Apoorva D. Patel | Apoorva Patel (CTS, IISc, Bangalore, India) | What is Quantum Computation? | Latex, 17 pages, no figures. Invited talk presented at the
Indo-French workshop on "Probing Fundamental Problems with Lasers and Cold
Atoms", IIA, Bangalore, India, January 1999. To appear in the proceedings.
Summary of lectures presented at the "Discussion Meeting on Quantum
Computation", JNCASR, Bangalore, India, July 1999 | null | null | CTS-IISc/6-99 | quant-ph | null | Quantum computation is a rapidly progressing field today. What are its
principles? In what sense is it distinct from conventional computation? What
are its advantages and disadvantages? What type of problems can it address? How
practical is it to make a quantum computer? I summarise some of the important
concepts of quantum computation, in an attempt to answer these questions. A
deeper understanding of them would pave the way for future development.
| [
{
"version": "v1",
"created": "Mon, 27 Sep 1999 10:37:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Patel",
"Apoorva",
"",
"CTS, IISc, Bangalore, India"
]
] |
quant-ph/9909083 | Andrew G. White | P. G. Kwiat (1), A. G. White (1), J. R. Mitchell (1), O. Nairz (2), G.
Weihs (2), H. Weinfurter (2), and A. Zeilinger (2) ((1) Los Alamos National
Laboratory (2) University of Innsbruck) | High-efficiency quantum interrogation measurements via the quantum Zeno
effect | 4 pages, 3 postscript figures. To appear in Phys. Rev. Lett;
submitted June 11, 1999 | Physical Review Letters 83, no. 23, pp. 4725-4728 (1999). | 10.1103/PhysRevLett.83.4725 | LAUR 98-5654 | quant-ph | null | The phenomenon of quantum interrogation allows one to optically detect the
presence of an absorbing object, without the measuring light interacting with
it. In an application of the quantum Zeno effect, the object inhibits the
otherwise coherent evolution of the light, such that the probability that an
interrogating photon is absorbed can in principle be arbitrarily small. We have
implemented this technique, demonstrating efficiencies exceeding the 50%
theoretical-maximum of the original ``interaction-free'' measurement proposal.
We have also predicted and experimentally verified a previously unsuspected
dependence on loss; efficiencies of up to 73% were observed and the feasibility
of efficiencies up to 85% was demonstrated.
| [
{
"version": "v1",
"created": "Mon, 27 Sep 1999 16:52:07 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Kwiat",
"P. G.",
""
],
[
"White",
"A. G.",
""
],
[
"Mitchell",
"J. R.",
""
],
[
"Nairz",
"O.",
""
],
[
"Weihs",
"G.",
""
],
[
"Weinfurter",
"H.",
""
],
[
"Zeilinger",
"A.",
""
]
] |
quant-ph/9909084 | V. Hushwater | V. Hushwater | Radiation Pressure Approach to the Repulsive Casimir Force | 11 pages, Revised summary of talk given to ITAMP Topical Group on
Casimir Forces, Cambridge, MA, March 16-27, 1998 | null | null | null | quant-ph | null | We study the Casimir force between a perfectly conducting and an infinitely
permeable plate with the radiation pressure approach. This method illustrates
how a repulsive force arises as a consequence of the redistribution of the
vacuum-field modes corresponding to specific boundary conditions. We discuss
also how the method of the zero-point radiation pressure follows from QED.
| [
{
"version": "v1",
"created": "Mon, 27 Sep 1999 21:54:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hushwater",
"V.",
""
]
] |
quant-ph/9909085 | Arkadiusz Jadczyk | Ph. Blanchard, A. Jadczyk and R. Olkiewicz | Completely Mixing Quantum Open Systems and Quantum Fractals | Latex format, 20 pages, 6 figures in jpg format. New replacement has
two more references (including one to a paper by G. Casati et al on quantum
fractal eigenstates), adds example and comments concerning mixing properties
of of a two-level atom driven by a laser field, and also adds a number of
other remarks which should make it easier to follow mathematical arguments | Physica D: Nonlinear Phenomena, 148 (3-4) (2001) pp. 227-241 | 10.1016/S0167-2789(00)00175-5 | null | quant-ph chao-dyn nlin.CD | null | Departing from classical concepts of ergodic theory, formulated in terms of
probability densities, measures describing the chaotic behavior and the loss of
information in quantum open systems are proposed. As application we discuss the
chaotic outcomes of continuous measurement processes in the EEQT framework.
Simultaneous measurement of four noncommuting spin components is shown to lead
to a chaotic jump on quantum spin sphere and to generate specific fractal
images - nonlinear ifs (iterated function system). The model is purely
theoretical at this stage, and experimental confirmation of the chaotic
behavior of measuring instruments during simultaneous continuous measurement of
several noncommuting quantum observables would constitute a quantitative
verification of Event Enhanced Quantum Theory.
| [
{
"version": "v1",
"created": "Tue, 28 Sep 1999 11:16:54 GMT"
},
{
"version": "v2",
"created": "Sat, 9 Oct 1999 18:07:47 GMT"
},
{
"version": "v3",
"created": "Thu, 25 May 2000 01:58:47 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Blanchard",
"Ph.",
""
],
[
"Jadczyk",
"A.",
""
],
[
"Olkiewicz",
"R.",
""
]
] |
quant-ph/9909086 | Bo-Sture Skagerstam | Bo-Sture Skagerstam | Topics in Modern Quantum Optics | 97 pages, 23 figures, 187 references. Misprints corrected, most
figures redrawn and references updated | null | null | null | quant-ph | null | This is the written version of lectures presented at "The 17th Symposium on
Theoretical Physics - Applied Field Theory", 29 June - 1 July, 1998, the
Sangsan Mathematical Science Building, Seoul National University, Seoul, Korea.
| [
{
"version": "v1",
"created": "Tue, 28 Sep 1999 17:35:03 GMT"
},
{
"version": "v2",
"created": "Sat, 6 Nov 1999 15:15:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Skagerstam",
"Bo-Sture",
""
]
] |
quant-ph/9909087 | Nikolaj A. Ketsaris | A. A. Ketsaris | Generalized equation of relativistic quantum mechanics in a gauge field | 13 pages, no figures, uses revtex, submitted to Phys.Rev.D | null | null | null | quant-ph | null | We develop an unified algebraic approach to the description of gauge
interactions within the framework of a new concept of quantum mechanics. The
next step in generalizing the space-time and the action vector space is made.
The gauge field is defined through linear mappings in the generalized
space-time and the action space. Relativistic quantum mechanics equations for
particles in a gauge field are derived from the structure equations for the
action space expanded in the linear mappings of action vectors. In a special
case, these equations are reduced to the relativistic equations for the leptons
in the electroweak field. As against the standard Glashow-Weinberg-Salam model,
the set of equations includes the equation for the right neutrino interacting
only with the weak Z-field.
| [
{
"version": "v1",
"created": "Tue, 28 Sep 1999 17:56:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ketsaris",
"A. A.",
""
]
] |
quant-ph/9909088 | Georgios Nikolopoulos | Georgios M. Nikolopoulos, S{\o}ren Bay and P. Lambropoulos | Quantum systems coupled to a structured reservoir with multiple
excitations | LaTeX format, 4 pages, 2 figures, to appear in Physical Review A | null | 10.1103/PhysRevA.60.5079 | null | quant-ph | null | We present a method for dealing with quantum systems coupled to a structured
reservoir with any density of modes and with more than one excitation. We apply
the method to a two-level atom coupled to the edge of a photonic band gap and a
defect mode. Results pertaining to this system, provide the solution to the
problem of two photons in the reservoir and possible generalization is
discussed.
| [
{
"version": "v1",
"created": "Wed, 29 Sep 1999 08:14:45 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Nikolopoulos",
"Georgios M.",
""
],
[
"Bay",
"Søren",
""
],
[
"Lambropoulos",
"P.",
""
]
] |
quant-ph/9909089 | Alberto Carlini | A. Carlini and A. Hosoya | Quantum Computers and Unstructured Search: Finding and Counting Items
with an Arbitrarily Entangled Initial State | Completely revised version, accepted for publ. on PLA.; 11 pages | null | null | TIT/HEP-430/COSMO-96 | quant-ph | null | Grover's quantum algorithm for an unstructured search problem and the Count
algorithm by Brassard et al. are generalized to the case when the initial state
is arbitrarily and maximally entangled. This ansatz might be relevant with
quantum subroutines, when the computational qubits and the environment are
coupled, and in general when the control over the quantum system is partial.
| [
{
"version": "v1",
"created": "Wed, 29 Sep 1999 08:17:54 GMT"
},
{
"version": "v2",
"created": "Mon, 4 Oct 1999 07:14:04 GMT"
},
{
"version": "v3",
"created": "Mon, 22 Jan 2001 09:43:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Carlini",
"A.",
""
],
[
"Hosoya",
"A.",
""
]
] |
quant-ph/9909090 | Vincent Buonomano | Vincent Buonomano | A Co-Operative Phenomena Type Local Realistic Theory | 8 pages, 1 figure (GIF) | null | null | null | quant-ph | null | We analyze a conceivable type of local realistic theory, which we call a
co-operative phenomena type local realistic theory. In an experimental
apparatus to measure second or fourth order interference effects, it images
that their exists a stable global pattern or mode in a hypothesized medium that
is at least the size of the coherence volume of all the involved beams. If you
change the position of a mirror, beam splitter, polarizer, state preparation,
or block a beam then a new and different stable global state is entered very
quickly. In an interferometer a photon passes only one arm of the apparatus but
knows if the other arm is open or closed since the global pattern through which
it travels through contains this information and guides it appropriately. In a
polarization correlation experiment, two distant polarizers are part of the
same global pattern or state which is very rapidly determined by the whole
apparatus. It is experimentally testable. The situation in relationship to the
special relativity is also discussed.
| [
{
"version": "v1",
"created": "Wed, 29 Sep 1999 13:58:09 GMT"
},
{
"version": "v2",
"created": "Sun, 3 Oct 1999 18:04:33 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Buonomano",
"Vincent",
""
]
] |
quant-ph/9909091 | Eugenio DelRe | E. DelRe (1), B. Crosignani (2), and P. Di Porto (2) ((1) Fondazione
Ugo Bordoni, (2) Dipartimento di Fisica, Universita' dell'Aquila) | A scheme for total quantum teleportation | 6 pages | null | 10.1103/PhysRevLett.84.2989 | null | quant-ph | null | We address the issue of totally teleporting the quantum state of an external
particle, as opposed to studies on partial teleportation of external
single-particle states, total teleportation of coherent states and encoded
single-particle states, and intramolecular teleportation of nuclear spin
states. We find a set of commuting observables whose measurement directly
projects onto the Bell-basis and discuss a possible experiment, based on
two-photon absorption, allowing, for the first time, total teleportation of the
state of a single external photon through a direct projective measurement.
| [
{
"version": "v1",
"created": "Wed, 29 Sep 1999 16:17:58 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"DelRe",
"E.",
""
],
[
"Crosignani",
"B.",
""
],
[
"Di Porto",
"P.",
""
]
] |
quant-ph/9909092 | Ali Mostafazadeh | Ali Mostafazadeh | Comment on Identical Motion in Classical and Quantum Mechanics | Plain Latex, accepted for publication in Phys. Rev. A | Phys.Rev. A60 (1999) 5144-5145 | 10.1103/PhysRevA.60.5144 | null | quant-ph hep-th | null | Makowski and Konkel [Phys. Rev. A 58, 4975 (1998)] have obtained certain
classes of potentials which lead to identical classical and quantum
Hamilton-Jacobi equations. We obtain the most general form of these potential.
| [
{
"version": "v1",
"created": "Thu, 30 Sep 1999 13:11:10 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Mostafazadeh",
"Ali",
""
]
] |
quant-ph/9909093 | Ali Mostafazadeh | Ali Mostafazadeh | Noncyclic geometric phase and its non-Abelian generalization | Plain Latex, accepted for publication in J. Phys. A: Math. Gen | J.Phys.A32:8157-8171,1999 | 10.1088/0305-4470/32/46/312 | null | quant-ph hep-th | null | We use the theory of dynamical invariants to yield a simple derivation of
noncyclic analogues of the Abelian and non-Abelian geometric phases. This
derivation relies only on the principle of gauge invariance and elucidates the
existing definitions of the Abelian noncyclic geometric phase. We also discuss
the adiabatic limit of the noncyclic geometric phase and compute the adiabatic
non-Abelian noncyclic geometric phase for a spin 1 magnetic (or electric)
quadrupole interacting with a precessing magnetic (electric) field.
| [
{
"version": "v1",
"created": "Thu, 30 Sep 1999 13:03:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mostafazadeh",
"Ali",
""
]
] |
quant-ph/9909094 | Emanuel Knill | E. Knill, R. Laflamme | Quantum Computation and Quadratically Signed Weight Enumerators | 7 pages | null | null | null | quant-ph cs.CC | null | We prove that quantum computation is polynomially equivalent to classical
probabilistic computation with an oracle for estimating the value of simple
sums, quadratically signed weight enumerators. The problem of estimating these
sums can be cast in terms of promise problems and has two interesting variants.
An oracle for the unconstrained variant may be more powerful than quantum
computation, while an oracle for a more constrained variant is efficiently
solvable in the one-bit model of quantum computation. Thus, problems involving
estimation of quadratically signed weight enumerators yield problems in BQP
(bounded error quantum polynomial time) that are distinct from the ones studied
so far, include a canonical BQP complete problem, and can be used to define and
study complexity classes and their relationships to quantum computation.
| [
{
"version": "v1",
"created": "Thu, 30 Sep 1999 22:24:33 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Knill",
"E.",
""
],
[
"Laflamme",
"R.",
""
]
] |
quant-ph/9910001 | Carlton M. Caves | Carlton M. Caves (1) and Gerard J. Milburn (2) ((1) University of New
Mexico, (2) University of Queensland) | Qutrit Entanglement | 12 pages; formatted in REVTEX; no figures; submitted to Optics
Communications on September 1, 1999 | null | 10.1016/S0030-4018(99)00693-8 | null | quant-ph | null | We consider the separability of various joint states for N qutrits. We derive
two results: (i) the separability condition for a two-qutrit state that is a
mixture of the maximally mixed state and a maximally entangled state (such a
state is a generalization of the Werner state for two qubits); (ii) upper and
lower bounds on the size of the neighborhood of separable states surrounding
the maximally mixed state for N qutrits.
| [
{
"version": "v1",
"created": "Thu, 30 Sep 1999 23:12:10 GMT"
},
{
"version": "v2",
"created": "Wed, 10 Nov 1999 18:00:56 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Caves",
"Carlton M.",
""
],
[
"Milburn",
"Gerard J.",
""
]
] |
quant-ph/9910002 | Dr Matthew J. Donald | Matthew J. Donald and Michal Horodecki | Continuity of Relative Entropy of Entanglement | 3 pages, RevTeX | Physics Letters A 264 (1999) 257-260 | null | null | quant-ph | null | We show that an entanglement measure called relative entropy of entanglement
satisfies a strong continuity condition. If two states are close to each other
then so are their entanglements per particle pair in this measure. It follows
in particular, that the measure is appropriate for the description of
entanglement manipulations in the limit of an infinite number of pairs of
particles.
| [
{
"version": "v1",
"created": "Fri, 1 Oct 1999 10:45:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Donald",
"Matthew J.",
""
],
[
"Horodecki",
"Michal",
""
]
] |
quant-ph/9910003 | Alina Suzko | A.A. Suzko and E.P. Velicheva (Joint Institute for Nuclear Research,
Dubna, Russia) | Exact solutions of nonstationary Schredinger equations and geometric
phase | 8 pages, Latex | Yadernaya Fizika 61 (1998) 1884-1888 | null | null | quant-ph | null | A procedure of solving nonstationary Schredinger equations in the exact
analytic form is elaborated on the basis of exactly solvable stationary models.
The exact solutions are employed to study the nonadiabatic geometric phase.
| [
{
"version": "v1",
"created": "Fri, 1 Oct 1999 12:53:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Suzko",
"A. A.",
"",
"Joint Institute for Nuclear Research,\n Dubna, Russia"
],
[
"Velicheva",
"E. P.",
"",
"Joint Institute for Nuclear Research,\n Dubna, Russia"
]
] |
quant-ph/9910004 | Shasanka Mohan Roy | S.M.Roy and Anu Venugopalan | Exact Solutions of the Caldeira-Leggett Master Equation: A Factorization
Theorem For Decoherence | 8 pages, latex | null | null | TIFR/TH/99-46 | quant-ph | null | Exact solutions of the Caldeira-Leggett Master equation for the reduced
density matrix for a free particle and for a harmonic oscillator system coupled
to a heat bath of oscillators are obtained for arbitrary initial conditions.
The solutions prove that the Fourier transform of the density matrix at time t
with respect to (x + x')/2, where x and x' are the initial and final
coordinates, factorizes exactly into a part depending linearly on the initial
density matrix and a part independent of it. The theorem yields the exact
initial state dependence of the density operator at time t and its eventual
diagonalization in the energy basis.
| [
{
"version": "v1",
"created": "Fri, 1 Oct 1999 13:47:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Roy",
"S. M.",
""
],
[
"Venugopalan",
"Anu",
""
]
] |
quant-ph/9910005 | Sergio De Filippo | Sergio De Filippo | Quantum Computation using Decoherence-Free States of the Physical
Operator Algebra | 16 pages, LATEX/REVTEX, expanded version to appear in Phys. Rev. A | null | 10.1103/PhysRevA.62.052307 | null | quant-ph cond-mat hep-th | null | The states of the physical algebra, namely the algebra generated by the
operators involved in encoding and processing qubits, are considered instead of
those of the whole system-algebra. If the physical algebra commutes with the
interaction Hamiltonian, and the system Hamiltonian is the sum of arbitrary
terms either commuting with or belonging to the physical algebra, then its
states are decoherence free. One of the considered examples shows that, for a
uniform collective coupling to the environment, the smallest number of physical
qubits encoding a decoherence free logical qubit is reduced from four to three.
| [
{
"version": "v1",
"created": "Fri, 1 Oct 1999 17:07:59 GMT"
},
{
"version": "v2",
"created": "Sun, 3 Oct 1999 06:29:07 GMT"
},
{
"version": "v3",
"created": "Mon, 7 Aug 2000 11:37:40 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"De Filippo",
"Sergio",
""
]
] |
quant-ph/9910006 | David Collins | David Collins (1), K. W. Kim (1), W. C. Holton (1), H.
Sierzputowska-Gracz (2), and E. O. Stejskal (3) ((1) Electrical and Computer
Engineering, (2) Biochemistry, (3) Chemistry, North Carolina State
University, Raleigh, NC) | NMR quantum computation with indirectly coupled gates | 9 pages, 2 figures. 10 additional figures illustrating output spectra | null | 10.1103/PhysRevA.62.022304 | null | quant-ph | null | An NMR realization of a two-qubit quantum gate which processes quantum
information indirectly via couplings to a spectator qubit is presented in the
context of the Deutsch-Jozsa algorithm. This enables a successful comprehensive
NMR implementation of the Deutsch-Jozsa algorithm for functions with three
argument bits and demonstrates a technique essential for multi-qubit quantum
computation.
| [
{
"version": "v1",
"created": "Fri, 1 Oct 1999 18:53:24 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Collins",
"David",
""
],
[
"Kim",
"K. W.",
""
],
[
"Holton",
"W. C.",
""
],
[
"Sierzputowska-Gracz",
"H.",
""
],
[
"Stejskal",
"E. O.",
""
]
] |
quant-ph/9910007 | Bo-Sture Skagerstam | Per Rekdal and Bo-Sture Skagerstam | Quantum Dynamics of Non-Degenerate Parametric Amplification | 32 pages, 13 figures. Accepted for publication in Physica Scripta | null | 10.1238/Physica.Regular.061a00296 | null | quant-ph | null | A simple model of a two-mode non-resonant parametric amplifier is studied
with special regard to non-classical features such as revivals and squeezing.
The methods used apply for an arbitrary pump parameter. Detailed analytical and
explicit expressions are given when the coupling of the two modes has an
harmonic time-dependence. Despite its simplicity the model exhibits a very
broad range of intricate physical effects. We show that quantum revivals are
possible for a broad continuous range of physical parameters in the case of
initial Fock states. For coherent states we find that such revivals are
possible only for certain discrete rational number combinations of the ratio of
frequency detuning and pump parameters. Correlation effects are shown to be
very sensitive to the initial state of the system.
| [
{
"version": "v1",
"created": "Fri, 1 Oct 1999 19:47:56 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Rekdal",
"Per",
""
],
[
"Skagerstam",
"Bo-Sture",
""
]
] |
quant-ph/9910008 | Oscar Rosas-Ortiz | D. J. Fernandez C. and O. Rosas-Ortiz | Evolution loops and spin-1/2 systems | 8 pages, LaTeX file, no figures. To appear in Rep. Math. Phys | Coherent States, Quantization and Gravity; M. Schlichenmaier et al
(Eds), Warsaw University Press, Poland (2001) 81-88 | null | null | quant-ph | null | The derivation of a new family of magnetic fields inducing exactly solvable
spin evolutions is presented. The conditions for which these fields generate
the evolution loops (dynamical processes for which any spin state evolves
cyclically) are studied. Their natural connection with geometric phases and the
corresponding calculation is also elaborated.
| [
{
"version": "v1",
"created": "Sun, 3 Oct 1999 18:05:19 GMT"
}
] | 2008-10-13T00:00:00 | [
[
"C.",
"D. J. Fernandez",
""
],
[
"Rosas-Ortiz",
"O.",
""
]
] |
quant-ph/9910009 | Oscar Rosas-Ortiz | O. Rosas-Ortiz, B Mielnik and L. M. Nieto | Backlund-type superposition and free particle n-susy partners | 4 pages, LaTeX file, no figures. To appear in proceedings of the 6th
International Conference on Squeezed States and Uncertainty Relations
(ICSSUR'99). Napoli, Italy, May 24-29 (1999) | Sixth International Conference on Squeezed States and Uncertainty
Relations D. Han and S. Solimeno (Eds.), NASA/CP-2000-209899 (2000) 218-221 | null | null | quant-ph | null | The higher order susy partners of Schroedinger Hamiltonians can be explicitly
constructed by iterating a nonlinear difference algorithm coinciding with the
Backlund superposition principle used in soliton theory. As an example, it is
applied in the construction of new higher order susy partners of the free
particle potential, which can be used as a handy tool in soliton theory.
| [
{
"version": "v1",
"created": "Sun, 3 Oct 1999 18:24:58 GMT"
}
] | 2008-10-13T00:00:00 | [
[
"Rosas-Ortiz",
"O.",
""
],
[
"Mielnik",
"B",
""
],
[
"Nieto",
"L. M.",
""
]
] |
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