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2025-04-04 00:00:00
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/0605142
|
Thomas Marlow
|
Thomas Marlow
|
Into the Fold: Searching for a Theory of Natural Inference
|
9 pages; v2: minor corrections v3: minor discussion added
| null | null | null |
quant-ph gr-qc
| null |
We introduce relationalism and discuss how it is useful for interpreting
probability theory and quantum mechanics. This paper is written in relatively
lay terms and presumes no prior knowledge of quantum theory.
|
[
{
"version": "v1",
"created": "Tue, 16 May 2006 16:00:08 GMT"
},
{
"version": "v2",
"created": "Fri, 19 May 2006 11:25:29 GMT"
},
{
"version": "v3",
"created": "Wed, 25 Oct 2006 14:47:45 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Marlow",
"Thomas",
""
]
] |
quant-ph/0605143
|
David Menzies
|
David Menzies and Natalia Korolkova
|
Procrustean entanglement concentration of continuous variable states of
light
|
6 pages, 3 figures; Typos corrected, References added and conclusion
extended, Accepted for publication in Physical Review A
|
Phys. Rev A, 74, 042315 (2006).
|
10.1103/PhysRevA.74.042315
| null |
quant-ph
| null |
We propose a Procrustean entanglement concentration scheme for continuous
variable states inspired by the scheme proposed in Fiurasek et. al. Phys. Rev.
A 67, 022304, (2003). We show that the eight-port homodyne measurement of
Fiurasek et. al. Phys. Rev. A 67, 022304, (2003) can be replaced by a balanced
homodyne measurement with the advantage of providing a success criterion that
allows Alice and Bob to determine if entanglement concentration was achieved.
In addition, it facilitates a straightforward and feasible experimental
implementation.
|
[
{
"version": "v1",
"created": "Tue, 16 May 2006 17:25:12 GMT"
},
{
"version": "v2",
"created": "Wed, 17 May 2006 16:08:51 GMT"
},
{
"version": "v3",
"created": "Fri, 8 Sep 2006 10:56:24 GMT"
}
] | 2007-11-01T00:00:00 |
[
[
"Menzies",
"David",
""
],
[
"Korolkova",
"Natalia",
""
]
] |
quant-ph/0605144
|
Michele Caponigro
|
Michele Caponigro, Stefano Mancini, Vladimir I. Man'ko
|
A probabilistic approach to quantum mechanics based on tomograms
| null |
Forteschritte der Physik Vol.54, N.7 pp.602-612 (2006).
|
10.1002/prop.200610304
| null |
quant-ph
| null |
It is usually believed that a picture of Quantum Mechanics in terms of true
probabilities cannot be given due to the uncertainty relations. Here we discuss
a tomographic approach to quantum states that leads to a probability
representation of quantum states. This can be regarded as a classical-like
formulation of quantum mechanics which avoids the counterintuitive concepts of
wave function and density operator. The relevant concepts of quantum mechanics
are then reconsidered and the epistemological implications of such approach
discussed.
|
[
{
"version": "v1",
"created": "Tue, 16 May 2006 18:26:28 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Caponigro",
"Michele",
""
],
[
"Mancini",
"Stefano",
""
],
[
"Man'ko",
"Vladimir I.",
""
]
] |
quant-ph/0605145
|
Wesley B. Cardoso
|
W. B. Cardoso and N. G. de Almeida
|
Statistical properties of the truncated state with random coefficients
|
7 pages, 11 figures, accept for publication in Physics Letters A
|
Physics Letters A 356 (2006) 104-109
|
10.1016/j.physleta.2006.03.032
| null |
quant-ph
| null |
In this Letter we introduce the truncated state with random coefficients
(TSRC). As the coefficients of the TSRC have in principle no algorithm to
produce them, our question is concerned about to what type of properties will
characterize the TSRC. A general method to engineer TSRC in the running-wave
domain is employed, which includes the errors due to the nonidealities of
detectors and photocounts.
|
[
{
"version": "v1",
"created": "Tue, 16 May 2006 20:08:59 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Cardoso",
"W. B.",
""
],
[
"de Almeida",
"N. G.",
""
]
] |
quant-ph/0605146
|
Adam Miranowicz
|
Adam Miranowicz, Sahin Kaya Ozdemir, Jiri Bajer, Masato Koashi,
Nobuyuki Imoto
|
Selective truncations of an optical state using projection synthesis
|
4 pages, 2 figures
|
J. Opt. Soc. Am. B 24, 379-383 (2007)
|
10.1364/JOSAB.24.000379
| null |
quant-ph
| null |
Selective truncation of Fock-state expansion of an optical field can be
achieved using projection synthesis. The process removes predetermined Fock
states from the input field by conditional measurement and teleportation. We
present a scheme based on multiport interferometry to perform projection
synthesis. This scheme can be used both as a generalized quantum scissors
device, which filters out Fock states with photon numbers higher than a
predetermined value, and also as a quantum punching device, which selectively
removes specific Fock states making holes in the Fock-state expansion of the
input field.
|
[
{
"version": "v1",
"created": "Tue, 16 May 2006 20:51:35 GMT"
}
] | 2009-08-03T00:00:00 |
[
[
"Miranowicz",
"Adam",
""
],
[
"Ozdemir",
"Sahin Kaya",
""
],
[
"Bajer",
"Jiri",
""
],
[
"Koashi",
"Masato",
""
],
[
"Imoto",
"Nobuyuki",
""
]
] |
quant-ph/0605147
|
Iris Reichenbach
|
Iris Reichenbach, Andrew Silberfarb, Rene Stock, Ivan H. Deutsch
|
A quasi-Hermitian pseudopotential for higher partial wave scattering
|
8 pages, 4 figures, accepted by PRA v3: some typos were corrected,
published version
|
Phys. Rev. A 74, 042724 (2006)
|
10.1103/PhysRevA.74.042724
| null |
quant-ph cond-mat.other physics.atom-ph
| null |
We formulate a new quasi-Hermitian delta-shell pseudopotential for higher
partial wave scattering, and show that any such potential must have an
energy-dependent regularization. The quasi-Hermiticity of the Hamiltonian leads
to a complete set of biorthogonal wave functions that can be used as a basis to
expand and diagonalize other two-body Hamiltonians. We demonstrate this
procedure for the case of ultracold atoms in a polarization-gradient optical
lattice, interacting pairwise when two atoms are transported together from
separated lattice sites. Here the pseudopotential depends explicitly on the
trapping potential. Additionally, we calculate the location of trap-induced
resonances for higher partial waves, which occur when a molecular eigenstate is
shifted to resonance with a trap eigenstate. We verify the accuracy of the
pseudopotential approach using a toy model in which a square well acts as the
true interaction potential, and see excellent agreement.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 03:19:33 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Sep 2006 19:01:12 GMT"
},
{
"version": "v3",
"created": "Sat, 18 Nov 2006 01:51:50 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Reichenbach",
"Iris",
""
],
[
"Silberfarb",
"Andrew",
""
],
[
"Stock",
"Rene",
""
],
[
"Deutsch",
"Ivan H.",
""
]
] |
quant-ph/0605148
|
Tsuyoshi Ito
|
David Avis (1), Hiroshi Imai (2 and 3) and Tsuyoshi Ito (2 and 4) ((1)
McGill University, (2) The University of Tokyo, (3) Japan Science and
Technology Agency, (4) Japan Society for the Promotion of Science)
|
On the Relationship between Convex Bodies Related to Correlation
Experiments with Dichotomic Observables
|
17 pages, 2 figures
| null |
10.1088/0305-4470/39/36/010
| null |
quant-ph
| null |
In this paper we explore further the connections between convex bodies
related to quantum correlation experiments with dichotomic variables and
related bodies studied in combinatorial optimization, especially cut polyhedra.
Such a relationship was established in Avis, Imai, Ito and Sasaki (2005 J.
Phys. A: Math. Gen. 38 10971-87) with respect to Bell inequalities. We show
that several well known bodies related to cut polyhedra are equivalent to
bodies such as those defined by Tsirelson (1993 Hadronic J. S. 8 329-45) to
represent hidden deterministic behaviors, quantum behaviors, and no-signalling
behaviors. Among other things, our results allow a unique representation of
these bodies, give a necessary condition for vertices of the no-signalling
polytope, and give a method for bounding the quantum violation of Bell
inequalities by means of a body that contains the set of quantum behaviors.
Optimization over this latter body may be performed efficiently by semidefinite
programming. In the second part of the paper we apply these results to the
study of classical correlation functions. We provide a complete list of tight
inequalities for the two party case with (m,n) dichotomic observables when
m=4,n=4 and when min{m,n}<=3, and give a new general family of correlation
inequalities.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 05:41:47 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Avis",
"David",
"",
"2 and 3"
],
[
"Imai",
"Hiroshi",
"",
"2 and 3"
],
[
"Ito",
"Tsuyoshi",
"",
"2 and 4"
]
] |
quant-ph/0605149
|
Brian J. Smith
|
Brian J. Smith and M. G. Raymer
|
Two-photon wave mechanics
|
5 pages, 2 figures
|
Phys. Rev. A 74, 062104 (2006)
|
10.1103/PhysRevA.74.062104
| null |
quant-ph
| null |
The position-representation wave function for multi-photon states and its
equation of motion are introduced. A major strength of the theory is that it
describes the complete evolution (including polarization and entanglement) of
multi-photon states propagating through inhomogeneous media. As a demonstration
of the two-photon wave function's use, we show how two photons in an
orbital-angular-momentum entangled state decohere upon propagation through a
turbulent atmosphere.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 06:16:50 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Feb 2007 17:49:07 GMT"
},
{
"version": "v3",
"created": "Wed, 21 Feb 2007 10:56:08 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Smith",
"Brian J.",
""
],
[
"Raymer",
"M. G.",
""
]
] |
quant-ph/0605150
|
Maciej Liskiewicz
|
Andreas Jakoby, Maciej Liskiewicz, and Aleksander Madry
|
Using quantum oblivious transfer to cheat sensitive quantum bit
commitment
|
12 pages
| null | null | null |
quant-ph cs.CR
| null |
It is well known that unconditionally secure bit commitment is impossible
even in the quantum world. In this paper a weak variant of quantum bit
commitment, introduced independently by Aharonov et al. [STOC, 2000] and Hardy
and Kent [Phys. Rev. Lett. 92 (2004)] is investigated. In this variant, the
parties require some nonzero probability of detecting a cheating, i.e. if Bob,
who commits a bit b to Alice, changes his mind during the revealing phase then
Alice detects the cheating with a positive probability (we call this property
binding); and if Alice gains information about the committed bit before the
revealing phase then Bob discovers this with positive probability (sealing). In
our paper we give quantum bit commitment scheme that is simultaneously binding
and sealing and we show that if a cheating gives epsilon advantage to a
malicious Alice then Bob can detect the cheating with a probability
Omega(epsilon^2). If Bob cheats then Alice's probability of detecting the
cheating is greater than some fixed constant lambda>0. This improves the
probabilities of cheating detections shown by Hardy and Kent and the scheme by
Aharonov et al. who presented a protocol that is either binding or sealing, but
not simultaneously both. To construct a cheat sensitive quantum bit commitment
scheme we use a protocol for a weak quantum one-out-of-two oblivious transfer.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 06:30:20 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Jakoby",
"Andreas",
""
],
[
"Liskiewicz",
"Maciej",
""
],
[
"Madry",
"Aleksander",
""
]
] |
quant-ph/0605151
|
Levay Peter
|
P\'eter L\'evay
|
On the geometry of four qubit invariants
|
19 pages
|
J. Phys. A: Math. Gen. 39 (2006) 9533-9545
|
10.1088/0305-4470/39/30/009
| null |
quant-ph math-ph math.MP
| null |
The geometry of four-qubit entanglement is investigated. We replace some of
the polynomial invariants for four-qubits introduced recently by new ones of
direct geometrical meaning. It is shown that these invariants describe four
points, six lines and four planes in complex projective space ${\bf CP}^3$. For
the generic entanglement class of stochastic local operations and classical
communication they take a very simple form related to the elementary symmetric
polynomials in four complex variables. Moreover, their magnitudes are
entanglement monotones that fit nicely into the geometric set of $n$-qubit ones
related to Grassmannians of $l$-planes found recently. We also show that in
terms of these invariants the hyperdeterminant of order 24 in the four-qubit
amplitudes takes a more instructive form than the previously published
expressions available in the literature. Finally in order to understand two,
three and four-qubit entanglement in geometric terms we propose a unified
setting based on ${\bf CP}^3$ furnished with a fixed quadric.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 07:30:27 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Lévay",
"Péter",
""
]
] |
quant-ph/0605152
|
Roger Andrews Dr
|
A T Joseph1, R Andrews1, E R Pike2 and S Sarkar2
|
Phase-modulated shaping of narrowband type-I parametric down-converted
photons
| null | null | null | null |
quant-ph
| null |
We present a general theoretical description of the temporal shaping of
narrowband noncollinear type-I down-converted photons using a spectral phase
filter with a symmetric phase distribution. By manipulating the spectral phase
of the signal or idler photon, we demonstrate control of the correlation time
and shape of the two-photon wave function with modulation frequency and
modulation depth of the phase distribution.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 13:02:57 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Joseph1",
"A T",
""
],
[
"Andrews1",
"R",
""
],
[
"Pike2",
"E R",
""
],
[
"Sarkar2",
"S",
""
]
] |
quant-ph/0605153
|
Feng Pan
|
Feng Pan, and J. P. Draayer
|
M-body Pure State Entanglement
|
9 pages, 2 figures
|
International Journal of Quantum Information 4 (2006) 965
| null | null |
quant-ph cond-mat.mes-hall
| null |
The simple entanglement of N-body N-particle pure states is extended to the
more general M-body or M-body N-particle states where $N\neq M$. Some new
features of the M-body N-particle pure states are discussed. An application of
the measure to quantify quantum correlations in a Bose-Einstien condensate
model is demonstrated.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 15:09:43 GMT"
},
{
"version": "v2",
"created": "Sun, 14 Jan 2007 16:43:53 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Pan",
"Feng",
""
],
[
"Draayer",
"J. P.",
""
]
] |
quant-ph/0605154
|
Evgeny Shchukin
|
E. Shchukin and W. Vogel
|
Multipartite continuous-variable entanglement
|
4 pages, 1 figures, modified and corrected version
| null |
10.1103/PhysRevA.74.030302
| null |
quant-ph
| null |
Necessary and sufficient observable conditions for the nonnegativity of all
partial transpositions of multi-mode quantum states are derived. The result is
a hierarchy of inequalities for minors in terms of moments of the given state.
Violations of any inequality is a sufficient condition for entanglement. Full
entanglement can be certified for a manifold of multi-mode quantum states. A
\textit{Mathematica} package is given for a systematic test of the hierarchy of
conditions.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 18:25:27 GMT"
},
{
"version": "v2",
"created": "Wed, 14 Jun 2006 08:56:52 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Shchukin",
"E.",
""
],
[
"Vogel",
"W.",
""
]
] |
quant-ph/0605155
|
Daniel Cavalcanti
|
Daniel Cavalcanti and Marcelo O. Terra Cunha
|
Estimating entanglement of unknown states
|
3 pages, 1 figure. Comments welcome. V2: references updated. Accepted
version by Applied Physics Letters
|
Appl. Phys. Lett. 89, 084102 (2006)
|
10.1063/1.2337535
| null |
quant-ph cond-mat.str-el
| null |
The experimental determination of entanglement is a major goal in the quantum
information field. In general the knowledge of the state is required in order
to quantify its entanglement. Here we express a lower bound to the robustness
of entanglement of a state based only on the measurement of the energy
observable and on the calculation of a separability energy. This allows the
estimation of entanglement dismissing the knowledge of the state in question.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 21:06:43 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Aug 2006 18:32:09 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Cavalcanti",
"Daniel",
""
],
[
"Cunha",
"Marcelo O. Terra",
""
]
] |
quant-ph/0605156
|
Mary Beth Ruskai
|
Percy Deift, Mary Beth Ruskai and Wolfgang Spitzer
|
Improved Gap Estimates for Simulating Quantum Circuits by Adiabatic
Evolution
| null |
Quantum Inf. Process 6, 121-125 (2007)
| null | null |
quant-ph
| null |
We use elementary variational arguments to prove, and improve on, gap
estimates which arise in simulating quantum circuits by adiabatic evolution.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 21:38:23 GMT"
}
] | 2009-01-14T00:00:00 |
[
[
"Deift",
"Percy",
""
],
[
"Ruskai",
"Mary Beth",
""
],
[
"Spitzer",
"Wolfgang",
""
]
] |
quant-ph/0605157
|
Asoka Biswas
|
Asoka Biswas and Daniel A. Lidar
|
Robust transmission of non-Gaussian entanglement over optical fibers
|
9 pages, 2 figures, RevTeX4, submitted to PRA
|
Phys. Rev. A 74, 062303 (2006)
|
10.1103/PhysRevA.74.062303
| null |
quant-ph
| null |
We show how the entanglement in a wide range of continuous variable
non-Gaussian states can be preserved against decoherence for long-range quantum
communication through an optical fiber. We apply protection via
decoherence-free subspaces and quantum dynamical decoupling to this end. The
latter is implemented by inserting phase shifters at regular intervals $\Delta
$ inside the fiber, where $\Delta $ is roughly the ratio of the speed of light
in the fiber to the bath high-frequency cutoff. Detailed estimates of relevant
parameters are provided using the boson-boson model of system-bath interaction
for silica fibers, and $\Delta $ is found to be on the order of a millimeter.
|
[
{
"version": "v1",
"created": "Wed, 17 May 2006 22:09:37 GMT"
}
] | 2016-08-08T00:00:00 |
[
[
"Biswas",
"Asoka",
""
],
[
"Lidar",
"Daniel A.",
""
]
] |
quant-ph/0605158
|
Massimiliano Federico Sacchi
|
Massimiliano F. Sacchi
|
Information-disturbance tradeoff in estimating a maximally entangled
state
|
4 pages. Accepted for publication on Physical Review Letters
|
Phys. Rev. Lett. 96, 220502 (2006)
|
10.1103/PhysRevLett.96.220502
| null |
quant-ph
| null |
We derive the amount of information retrieved by a quantum measurement in
estimating an unknown maximally entangled state, along with the pertaining
disturbance on the state itself. The optimal tradeoff between information and
disturbance is obtained, and a corresponding optimal measurement is provided.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 08:07:04 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Sacchi",
"Massimiliano F.",
""
]
] |
quant-ph/0605159
|
Sergey Peletminskii
|
Sergey V. Peletminskii and Yuriy V. Slyusarenko
|
Second quantization method in the presence of bound states of particles
|
35 pages
|
J.Math.Phys. 46 (2005) 022301
|
10.1063/1.1812359
| null |
quant-ph cond-mat.stat-mech
| null |
We develop an approximate second quantization method for describing the
many-particle systems in the presence of bound states of particles at low
energies (the kinetic energy of particles is small in comparison to the binding
energy of compound particles). In this approximation the compound and
elementary particles are considered on an equal basis. This means that creation
and annihilation operators of compound particles can be introduced. The
Hamiltonians, which specify the interactions between compound and elementary
particles and between compound particles themselves are found in terms of the
interaction amplitudes for elementary particles. The nonrelativistic quantum
electrodynamics is developed for systems containing both elementary and
compound particles. Some applications of this theory are considered.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 12:24:25 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Peletminskii",
"Sergey V.",
""
],
[
"Slyusarenko",
"Yuriy V.",
""
]
] |
quant-ph/0605160
|
Shubeur Rahman Mr
|
S. Rahman, T. M. Stace, H. P. Langtangen, M. Kakaoka and C. H. W.
Barnes
|
Pulse-induced acoustoelectric vibrations in surface-gated GaAs-based
quantum devices
|
To be published in Phys. Rev. B
|
Phys. Rev. B, 75, 205303, (2007)
|
10.1103/PhysRevB.75.205303
| null |
quant-ph
| null |
We present the results of a numerical investigation which show the excitation
of acoustoelectric modes of vibration in GaAs-based heterostructures due to
sharp nano-second electric-field pulses applied across surface gates. In
particular, we show that the pulses applied in quantum information processing
applications are capable of exciting acoustoelectric modes of vibration
including surface acoustic modes which propagate for distances greater than
conventional device dimensions. We show that the pulse-induced acoustoelectric
vibrations are capable of inducing significant undesired perturbations to the
evolution of quantum systems.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 10:02:30 GMT"
},
{
"version": "v2",
"created": "Wed, 24 May 2006 15:10:33 GMT"
},
{
"version": "v3",
"created": "Wed, 27 Sep 2006 17:12:24 GMT"
},
{
"version": "v4",
"created": "Thu, 22 Mar 2007 09:30:35 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Rahman",
"S.",
""
],
[
"Stace",
"T. M.",
""
],
[
"Langtangen",
"H. P.",
""
],
[
"Kakaoka",
"M.",
""
],
[
"Barnes",
"C. H. W.",
""
]
] |
quant-ph/0605161
|
Madalin Guta
|
Madalin Guta and Keiji Matsumoto
|
Optimal cloning of mixed Gaussian states
|
8 pages, 1 figure; proof of general form of covariant amplifiers
added
|
Phys. Rev A, 74, 032305 (2006)
|
10.1103/PhysRevA.74.032305
| null |
quant-ph
| null |
We construct the optimal 1 to 2 cloning transformation for the family of
displaced thermal equilibrium states of a harmonic oscillator, with a fixed and
known temperature. The transformation is Gaussian and it is optimal with
respect to the figure of merit based on the joint output state and norm
distance. The proof of the result is based on the equivalence between the
optimal cloning problem and that of optimal amplification of Gaussian states
which is then reduced to an optimization problem for diagonal states of a
quantum oscillator. A key concept in finding the optimum is that of stochastic
ordering which plays a similar role in the purely classical problem of Gaussian
cloning. The result is then extended to the case of n to m cloning of mixed
Gaussian states.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 10:48:10 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Jun 2006 14:14:29 GMT"
}
] | 2011-06-23T00:00:00 |
[
[
"Guta",
"Madalin",
""
],
[
"Matsumoto",
"Keiji",
""
]
] |
quant-ph/0605162
|
Bruno Galvan
|
Bruno Galvan
|
Typicality vs. probability in trajectory-based formulations of quantum
mechanics
|
24 pages, no figures. To appear in Foundation of Physics
|
Found. Phys. 37 1540-1562 (2007)
|
10.1007/s10701-007-9174-0
| null |
quant-ph
| null |
Bohmian mechanics represents the universe as a set of paths with a
probability measure defined on it. The way in which a mathematical model of
this kind can explain the observed phenomena of the universe is examined in
general. It is shown that the explanation does not make use of the full
probability measure, but rather of a suitable set function deriving from it,
which defines relative typicality between single-time cylinder sets. Such a set
function can also be derived directly from the standard quantum formalism,
without the need of an underlying probability measure. The key concept for this
derivation is the {\it quantum typicality rule}, which can be considered as a
generalization of the Born rule. The result is a new formulation of quantum
mechanics, in which particles follow definite trajectories, but which is only
based on the standard formalism of quantum mechanics.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 12:47:38 GMT"
},
{
"version": "v10",
"created": "Wed, 26 Sep 2007 13:55:53 GMT"
},
{
"version": "v2",
"created": "Mon, 22 May 2006 17:54:07 GMT"
},
{
"version": "v3",
"created": "Sun, 4 Jun 2006 21:48:32 GMT"
},
{
"version": "v4",
"created": "Tue, 13 Jun 2006 13:19:33 GMT"
},
{
"version": "v5",
"created": "Tue, 5 Sep 2006 15:00:18 GMT"
},
{
"version": "v6",
"created": "Mon, 2 Oct 2006 14:15:03 GMT"
},
{
"version": "v7",
"created": "Tue, 7 Nov 2006 17:47:37 GMT"
},
{
"version": "v8",
"created": "Thu, 28 Dec 2006 19:31:14 GMT"
},
{
"version": "v9",
"created": "Mon, 22 Jan 2007 22:11:35 GMT"
}
] | 2007-11-20T00:00:00 |
[
[
"Galvan",
"Bruno",
""
]
] |
quant-ph/0605163
|
Philipp Treutlein
|
Philipp Treutlein, Tilo Steinmetz, Yves Colombe, Benjamin Lev, Peter
Hommelhoff, Jakob Reichel, Markus Greiner, Olaf Mandel, Arthur Widera, Tim
Rom, Immanuel Bloch, and Theodor W. H\"ansch
|
Quantum Information Processing in Optical Lattices and Magnetic
Microtraps
|
15 pages, 11 figures, corrected author list
|
Fortschr. Phys. 54, 702-718 (2006)
|
10.1002/prop.200610325
| null |
quant-ph
| null |
We review our experiments on quantum information processing with neutral
atoms in optical lattices and magnetic microtraps.
Atoms in an optical lattice in the Mott insulator regime serve as a large
qubit register. A spin-dependent lattice is used to split and delocalize the
atomic wave functions in a controlled and coherent way over a defined number of
lattice sites. This is used to experimentally demonstrate a massively parallel
quantum gate array, which allows the creation of a highly entangled many-body
cluster state through coherent collisions between atoms on neighbouring lattice
sites.
In magnetic microtraps on an atom chip, we demonstrate coherent manipulation
of atomic qubit states and measure coherence lifetimes exceeding one second at
micron-distance from the chip surface. We show that microwave near-fields on
the chip can be used to create state-dependent potentials for the
implementation of a quantum controlled phase gate with these robust qubit
states. For single atom detection and preparation, we have developed high
finesse fiber Fabry-Perot cavities and integrated them on the atom chip. We
present an experiment in which we detected a very small number of cold atoms
magnetically trapped in the cavity using the atom chip.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 19:23:40 GMT"
},
{
"version": "v2",
"created": "Fri, 9 Jun 2006 13:13:14 GMT"
}
] | 2007-11-10T00:00:00 |
[
[
"Treutlein",
"Philipp",
""
],
[
"Steinmetz",
"Tilo",
""
],
[
"Colombe",
"Yves",
""
],
[
"Lev",
"Benjamin",
""
],
[
"Hommelhoff",
"Peter",
""
],
[
"Reichel",
"Jakob",
""
],
[
"Greiner",
"Markus",
""
],
[
"Mandel",
"Olaf",
""
],
[
"Widera",
"Arthur",
""
],
[
"Rom",
"Tim",
""
],
[
"Bloch",
"Immanuel",
""
],
[
"Hänsch",
"Theodor W.",
""
]
] |
quant-ph/0605164
|
Shi-Jian Gu
|
Shi-Jian Gu, Chang-Pu Sun, and Hai-Qing Lin
|
Universal role of correlation entropy in critical phenomena
|
10 pages, 9 figures
|
J. Phys. A: Math. Theor. 41, 025002 (2008).
|
10.1088/1751-8113/41/2/025002
| null |
quant-ph cond-mat.stat-mech
| null |
In statistical physics, if we successively divide an equilibrium system into
two parts, we will face a situation that, within a certain length $\xi$, the
physics of a subsystem is no longer the same as the original system. Then the
extensive properties of the thermal entropy $S($AB$)= S($A$)+S($B$)$ is
violated. This observation motivates us to introduce the concept of correlation
entropy between two points, as measured by mutual information in the
information theory, to study the critical phenomena. A rigorous relation is
established to display some drastic features of the non-vanishing correlation
entropy of the subsystem formed by any two distant particles with long-range
correlation. This relation actually indicates the universal role of the
correlation entropy in understanding critical phenomena. We also verify these
analytical studies in terms of two well-studied models for both the thermal and
quantum phase transitions: two-dimensional Ising model and one-dimensional
transverse field Ising model. Therefore, the correlation entropy provides us
with a new physical intuition in critical phenomena from the point of view of
the information theory.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 13:30:09 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Gu",
"Shi-Jian",
""
],
[
"Sun",
"Chang-Pu",
""
],
[
"Lin",
"Hai-Qing",
""
]
] |
quant-ph/0605165
|
Hefeng Wang
|
Hefeng Wang and Sabre Kais
|
Quantum Teleportation in One-Dimensional Quantum Dots System
|
5 pages, two figures
|
Chemcal Physics Letter 421 (2006) 338-342
|
10.1016/j.physleta.2005.11.002
| null |
quant-ph
| null |
We present a model of quantum teleportation protocol based on one-dimensional
quantum dots system. Three quantum dots with three electrons are used to
perform teleportation, the unknown qubit is encoded using one electron spin on
quantum dot A, the other two dots B and C are coupled to form a mixed
space-spin entangled state. By choosing the Hamiltonian for the mixed
space-spin entangled system, we can filter the space (spin) entanglement to
obtain pure spin (space) entanglement and after a Bell measurement, the unknown
qubit is transfered to quantum dot B. Selecting an appropriate Hamiltonian for
the quantum gate allows the spin-based information to be transformed into a
charge-based information. The possibility of generalizing this model to
N-electrons is discussed.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 14:45:08 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Wang",
"Hefeng",
""
],
[
"Kais",
"Sabre",
""
]
] |
quant-ph/0605166
|
Magdalena Stobi\'nska
|
Magdalena Stobi\'nska, G. J. Milburn, Krzysztof W\'odkiewicz
|
Wigner Function Evolution of Quantum States in Presence of Self-Kerr
Interaction
|
10 pages, 11 figures
|
Phys. Rev. A 78, 013810 (2008)
|
10.1103/PhysRevA.78.013810
| null |
quant-ph
| null |
A Fokker-Planck equation for the Wigner function evolution in a noisy Kerr
medium ($\chi^{(3)}$ non-linearity) is presented. We numerically solved this
equation taking a coherent state as an initial condition. The dissipation
effects are discussed. We provide examples of quantum interference, sub-Planck
phase space structures, and Gaussian versus non-Gaussian dynamical evolution of
the state. The results also apply to the description of a nanomechanical
resonator with an intrinsic Duffing nonlinearity.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 14:59:12 GMT"
},
{
"version": "v2",
"created": "Mon, 9 Oct 2006 15:00:19 GMT"
},
{
"version": "v3",
"created": "Thu, 14 Feb 2008 22:00:31 GMT"
},
{
"version": "v4",
"created": "Tue, 20 May 2008 20:24:11 GMT"
}
] | 2010-05-04T00:00:00 |
[
[
"Stobińska",
"Magdalena",
""
],
[
"Milburn",
"G. J.",
""
],
[
"Wódkiewicz",
"Krzysztof",
""
]
] |
quant-ph/0605167
|
Olavi Dannenberg
|
Olavi Dannenberg
|
Coherence theory and coherence phenomena in a closed spin-1/2 system
|
31 pages, 5 figures, v2: major changes, accepted for publication
|
Ann. Phys. (Berlin) 17, No. 6, 355-373 (2008)
|
10.1002/andp.200710300
| null |
quant-ph
| null |
A simplified Heisenberg spin model is studied in order to examine the idea of
decoherence in closed quantum systems. For this purpose, we present a
quantifiable definition to quantum coherence $\Xi$, and discuss in some detail
a general coherence theory and its elementary results. As expected, decoherence
is understood as a statistical process that is caused by the dynamics of the
system, similar to the growth of entropy. It appears that coherence is an
important measure that helps to understand quantum properties of a system,
e.g., the decoherence time can be derived from the coherence function $\Xi(t)$,
but not from the entropy dynamics. Moreover, the concept of decoherence time is
applicable in closed and finite systems. However, in most cases, the decay of
off-diagonal elements differs from the usual $\exp(-t/\tau_{\rm d})$ behaviour.
For concreteness, we report the form of decoherence time $\tau_{\rm d}$ in a
finite Heisenberg model with respect to the number of particles $N$, density
$n_{\rho}$, spatial dimension $D$ and $\epsilon$ in a $\eta/r^{\epsilon}$-type
of potential.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 15:44:38 GMT"
},
{
"version": "v2",
"created": "Sun, 18 May 2008 16:04:16 GMT"
}
] | 2008-05-18T00:00:00 |
[
[
"Dannenberg",
"Olavi",
""
]
] |
quant-ph/0605168
|
Pablo Barberis-Blostein
|
P. Barberis-Blostein
|
Field autocorrelations in electromagnetically induced transparency:
Effects of a squeezed probe field
| null |
Phys. Rev. A 74, 013803 (2006)
|
10.1103/PhysRevA.74.013803
| null |
quant-ph
| null |
The interaction of a quantized field with three-level atoms in $\Lambda$
configuration inside a two mode cavity is analyzed. We calculate the stationary
quadrature noise spectrum of the field outside the cavity in the case where the
input probe field is in a squeezed state and the atoms show electromagnetically
induced transparency (EIT). If the Rabi frequencies of both dipole transitions
of the atoms are different from zero, we show that the output probe field have
four maxima of squeezing absorption. We show that in some cases two of these
frequencies can be very close to the transition frequency of the atom, in a
region where the mean value of the field entering the cavity is hardly altered.
Furthermore, part of the absorbed squeezing of the probe field is transfered to
the pump field. For some conditions this transfer of squeezing can be complete.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 21:34:46 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Barberis-Blostein",
"P.",
""
]
] |
quant-ph/0605169
|
Carlos Pineda
|
Carlos Pineda, Thomas H. Seligman
|
A Bell pair in a generic random matrix environment
|
4 pages, 3 figures
|
Phys. Rev. A 75(1), 012106, (2007).
|
10.1103/PhysRevA.75.012106
| null |
quant-ph
| null |
Two non-interacting qubits are coupled to an environment. Both coupling and
environment are represented by random matrix ensembles. The initial state of
the pair is a Bell state, though we also consider arbitrary pure states.
Decoherence of the pair is evaluated analytically in terms of purity; Monte
Carlo calculations confirm these results and also yield the concurrence of the
pair. Entanglement within the pair accelerates decoherence. Numerics display
the relation between concurrence and purity known for Werner states, allowing
us to give a formula for concurrence decay.
|
[
{
"version": "v1",
"created": "Thu, 18 May 2006 22:28:07 GMT"
}
] | 2007-11-22T00:00:00 |
[
[
"Pineda",
"Carlos",
""
],
[
"Seligman",
"Thomas H.",
""
]
] |
quant-ph/0605170
|
Joe Britton
|
J. Britton, D. Leibfried, J. Beall, R. B. Blakestad, J. J. Bollinger,
J. Chiaverini, R. J. Epstein, J. D. Jost, D. Kielpinski, C. Langer, R. Ozeri,
R. Reichle, S. Seidelin, N. Shiga, J. H. Wesenberg, and D. J. Wineland
|
A microfabricated surface-electrode ion trap in silicon
|
4 pages, 6 figures
| null | null | null |
quant-ph
| null |
The prospect of building a quantum information processor underlies many
recent advances ion trap fabrication techniques. Potentially, a quantum
computer could be constructed from a large array of interconnected ion traps.
We report on a micrometer-scale ion trap, fabricated from bulk silicon using
micro-electromechanical systems (MEMS) techniques. The trap geometry is
relatively simple in that the electrodes lie in a single plane beneath the
ions. In such a trap we confine laser-cooled 24Mg+ ions approximately 40
microns above the surface. The fabrication technique and planar electrode
geometry together make this approach amenable to scaling up to large trap
arrays. In addition we observe that little laser cooling light is scattered by
the electrodes.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 16:12:06 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Britton",
"J.",
""
],
[
"Leibfried",
"D.",
""
],
[
"Beall",
"J.",
""
],
[
"Blakestad",
"R. B.",
""
],
[
"Bollinger",
"J. J.",
""
],
[
"Chiaverini",
"J.",
""
],
[
"Epstein",
"R. J.",
""
],
[
"Jost",
"J. D.",
""
],
[
"Kielpinski",
"D.",
""
],
[
"Langer",
"C.",
""
],
[
"Ozeri",
"R.",
""
],
[
"Reichle",
"R.",
""
],
[
"Seidelin",
"S.",
""
],
[
"Shiga",
"N.",
""
],
[
"Wesenberg",
"J. H.",
""
],
[
"Wineland",
"D. J.",
""
]
] |
quant-ph/0605171
|
Tao Qin
|
Tao Qin, Meisheng Zhao and Yongde Zhang
|
The classical capacity for continuous variable teleportation channel
|
The formula of fidelity corrected; the figure of fidelity replotted;
submitted for publication
| null |
10.1088/0256-307X/24/2/007
| null |
quant-ph
| null |
The process of quantum teleportation can be considered as a quantum channel.
The exact classical capacity of the continuous variable teleportation channel
is given. Also, the channel fidelity is derived. Consequently, the properties
of the continuous variable quantum teleportation are discussed and interesting
results are obtained.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 01:54:08 GMT"
},
{
"version": "v2",
"created": "Wed, 14 Jun 2006 00:39:40 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Qin",
"Tao",
""
],
[
"Zhao",
"Meisheng",
""
],
[
"Zhang",
"Yongde",
""
]
] |
quant-ph/0605172
|
Rastegin Alexey Eduardovich
|
A. E. Rastegin
|
Trace distance from the viewpoint of quantum operation techniques
|
26 pages, no figures. The bibliography is extended, explanatory
improvements
|
J. Phys. A: Math. Theor. 40 (2007) 9533-9549
|
10.1088/1751-8113/40/31/026
| null |
quant-ph
| null |
In the present paper, the trace distance is exposed within the quantum
operations formalism. The definition of the trace distance in terms of a
maximum over all quantum operations is given. It is shown that for any pair of
different states, there are an uncountably infinite number of maximizing
quantum operations. Conversely, for any operation of the described type, there
are an uncountably infinite number of those pairs of states that the maximum is
reached by the operation. A behavior of the trace distance under considered
operations is studied. Relations and distinctions between the trace distance
and the sine distance are discussed.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 05:43:30 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Jan 2007 10:41:25 GMT"
},
{
"version": "v3",
"created": "Tue, 24 Jul 2007 08:27:49 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Rastegin",
"A. E.",
""
]
] |
quant-ph/0605173
|
Indranil Chakrabarty ic
|
Indranil Chakrabarty, A.K.Pati, Satyabrata Adhikari
|
Stronger no-cloning, no-signalling and conservation of quantum
information
| null | null | null | null |
quant-ph
| null |
It is known that the stronger no-cloning theorem and the no-deleting theorem
taken together provide the permanence property of quantum information. Also, it
is known that the violation of the no-deletion theorem would imply signalling.
Here, we show that the violation of the stronger no-cloning theorem could lead
to signalling. Furthermore, we prove the stronger no-cloning theorem from the
conservation of quantum information. These observations imply that the
permanence property of quantum information is connected to the no-signalling
and the conservation of quantum information.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 06:27:18 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Chakrabarty",
"Indranil",
""
],
[
"Pati",
"A. K.",
""
],
[
"Adhikari",
"Satyabrata",
""
]
] |
quant-ph/0605174
|
A. Heidmann
|
O. Arcizet, P.-F. Cohadon, T. Briant, M. Pinard, A. Heidmann, J.-M.
Mackowski, C. Michel, L. Pinard, O. Francais, L. Rousseau
|
High-sensitivity optical monitoring of a micro-mechanical resonator with
a quantum-limited optomechanical sensor
|
4 pages, 5 figures
|
Phys. Rev. Lett. 97 (2006) 133601
|
10.1103/PhysRevLett.97.133601
| null |
quant-ph
| null |
We experimentally demonstrate the high-sensitivity optical monitoring of a
micro-mechanical resonator and its cooling by active control. Coating a
low-loss mirror upon the resonator, we have built an optomechanical sensor
based on a very high-finesse cavity (30000). We have measured the thermal noise
of the resonator with a quantum-limited sensitivity at the 10^-19 m/rootHz
level, and cooled the resonator down to 5K by a cold-damping technique.
Applications of our setup range from quantum optics experiments to the
experimental demonstration of the quantum ground state of a macroscopic
mechanical resonator.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 11:22:27 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Arcizet",
"O.",
""
],
[
"Cohadon",
"P. -F.",
""
],
[
"Briant",
"T.",
""
],
[
"Pinard",
"M.",
""
],
[
"Heidmann",
"A.",
""
],
[
"Mackowski",
"J. -M.",
""
],
[
"Michel",
"C.",
""
],
[
"Pinard",
"L.",
""
],
[
"Francais",
"O.",
""
],
[
"Rousseau",
"L.",
""
]
] |
quant-ph/0605175
|
Yong Hu
|
Yong Hu, Zheng-Wei Zhou and Guang-Can Guo
|
Always On Non-Nearest-Neighbor Coupling in Scalable Quantum Computing
| null | null |
10.1088/1367-2630/9/2/027
| null |
quant-ph
| null |
We investigate the non-nearest-neighbor interaction effect in 1-D spin-1/2
chain model. In many previous schemes this long-range coupling is omitted
because of its relative weak strength compared with the nearest-neighbor
coupling. We show that the quantum gate deviation induced by the omitted
long-range interaction depends on not only its strength but also the scale of
the system. This implies that omitting the long-range interaction may challenge
the scalability of previous schemes. We further consider how to suppress this
unwanted effect. We propose a quantum computation scheme. In this scheme, by
using appropriate encoding method, we effectively negate the influence of the
next-nearest-neighbor interaction in order to improve the precision of quantum
gates. We also discuss the feasibility of this scheme in 1-D Josephson charge
qubit array system. This work may offer improvement in scalable quantum
computing.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 12:59:46 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Hu",
"Yong",
""
],
[
"Zhou",
"Zheng-Wei",
""
],
[
"Guo",
"Guang-Can",
""
]
] |
quant-ph/0605176
|
Dominic William Berry
|
Dominic W. Berry and Mark R. Dowling
|
Two qubits can be entangled in two distinct temperature regions
|
6 pages, 4 figures, many new results
|
Phys. Rev. A 74, 062301 (2006)
|
10.1103/PhysRevA.74.062301
| null |
quant-ph
| null |
We have found that for a wide range of two-qubit Hamiltonians the
canonical-ensemble thermal state is entangled in two distinct temperature
regions. In most cases the ground state is entangled; however we have also
found an example where the ground state is separable and there are still two
regions. This demonstrates that the qualitative behavior of entanglement with
temperature can be much more complicated than might otherwise have been
expected; it is not simply determined by the entanglement of the ground state,
even for the simple case of two qubits. Furthermore, we prove a finite bound on
the number of possible entangled regions for two qubits, thus showing that
arbitrarily many transitions from entanglement to separability are not
possible. We also provide an elementary proof that the spectrum of the thermal
state at a lower temperature majorizes that at a higher temperature, for any
Hamiltonian, and use this result to show that only one entangled region is
possible for the special case of Hamiltonians without magnetic fields.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 18:09:39 GMT"
},
{
"version": "v2",
"created": "Mon, 7 Aug 2006 06:37:36 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Berry",
"Dominic W.",
""
],
[
"Dowling",
"Mark R.",
""
]
] |
quant-ph/0605177
|
Grigori Amosov
|
G.G. Amosov
|
On Weyl channels being covariant with respect to the maximum commutative
group of unitaries
|
A completely revised version, 20 pages
|
J. Math. Phys. 48 (2007) no. 1, P. 2104-2117
|
10.1063/1.2406054
| null |
quant-ph
| null |
We investigate the Weyl channels being covariant with respect to the maximum
commutative group of unitary operators. This class includes the quantum
depolarizing channel and the "two-Pauli" channel as well. Then, we show that
our estimation of the output entropy for a tensor product of the phase damping
channel and the identity channel based upon the decreasing property of the
relative entropy allows to prove the additivity conjecture for the minimal
output entropy for the quantum depolarizing channel in any prime dimesnsion and
for the "two Pauli" channel in the qubit case.
|
[
{
"version": "v1",
"created": "Fri, 19 May 2006 18:34:08 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Jul 2006 13:41:06 GMT"
},
{
"version": "v3",
"created": "Thu, 10 Aug 2006 11:53:46 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Amosov",
"G. G.",
""
]
] |
quant-ph/0605178
|
Mahmoud Abdel-Aty
|
F. Saif, M. Abdel-Aty, M. Javed, R. Ul-Islam and A.-S. F. Obada
|
Generation of maximally entangled states of two cavity modes
|
10 pages
|
Appl. Math. Inf. Sci. Vol. 1 No. 3 pp. 323 (2007)
| null | null |
quant-ph
| null |
In this letter we present a scheme for generating maximally entangled states
of two cavity modes which enables us to generate complete set of Bell basis
states having rather simple initial state preparation. Furthermore, we study
the interaction of a two-level atom with two modes of electromagnetic field in
a high Q cavity. The two-level atom acts as a control qubit and the two mode
electromagnetic field serves as a target qubit. This simple system of quantum
electrodynamics provides us experimentally feasible universal quantum logic
gates.
|
[
{
"version": "v1",
"created": "Sat, 20 May 2006 14:27:03 GMT"
},
{
"version": "v2",
"created": "Sat, 3 May 2008 14:55:58 GMT"
}
] | 2008-05-03T00:00:00 |
[
[
"Saif",
"F.",
""
],
[
"Abdel-Aty",
"M.",
""
],
[
"Javed",
"M.",
""
],
[
"Ul-Islam",
"R.",
""
],
[
"Obada",
"A. -S. F.",
""
]
] |
quant-ph/0605179
|
Ronald Hanson
|
R. Hanson, F. M. Mendoza, R. J. Epstein, and D. D. Awschalom
|
Polarization and readout of coupled single spins in diamond
| null |
Phys. Rev. Lett. 97, 087601 (2006)
|
10.1103/PhysRevLett.97.087601
| null |
quant-ph cond-mat.mes-hall cond-mat.other
| null |
We study the coupling of a single nitrogen-vacancy center in diamond to a
nearby single nitrogen defect at room temperature. The magnetic dipolar
coupling leads to a splitting in the electron spin resonance frequency of the
nitrogen-vacancy center, allowing readout of the state of a single nitrogen
electron spin. At magnetic fields where the spin splitting of the two centers
is the same we observe a strong polarization of the nitrogen electron spin. The
amount of polarization can be controlled by the optical excitation power. We
combine the polarization and the readout in time-resolved pump-probe
measurements to determine the spin relaxation time of a single nitrogen
electron spin. Finally, we discuss indications for hyperfine-induced
polarization of the nitrogen nuclear spin.
|
[
{
"version": "v1",
"created": "Sat, 20 May 2006 23:07:05 GMT"
},
{
"version": "v2",
"created": "Wed, 23 Aug 2006 17:48:31 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Hanson",
"R.",
""
],
[
"Mendoza",
"F. M.",
""
],
[
"Epstein",
"R. J.",
""
],
[
"Awschalom",
"D. D.",
""
]
] |
quant-ph/0605180
|
Doron Cohen
|
Doron Cohen
|
Lecture Notes in Quantum Mechanics
|
295 pages with some figures, textual improvements, no structural
changes, equations numbered by section
| null | null | null |
quant-ph cond-mat.mes-hall
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
These lecture notes cover undergraduate textbook topics (e.g. as in Sakurai),
and also additional advanced topics at the same level of presentation. In
particular: EPR and Bell; Basic postulates; The probability matrix; Measurement
theory; Entanglement; Quantum computation; Wigner-Weyl formalism; The adiabatic
picture; Berry phase; Linear response theory; Kubo formula; Modern approach to
scattering theory with mesoscopic orientation; Theory of the resolvent and the
Green function; Gauge and Galilei Symmetries; Motion in magnetic field; Quantum
Hall effect; Quantization of the electromagnetic field; Fock space formalism.
|
[
{
"version": "v1",
"created": "Sun, 21 May 2006 07:28:50 GMT"
},
{
"version": "v2",
"created": "Wed, 14 Feb 2007 13:53:09 GMT"
},
{
"version": "v3",
"created": "Wed, 8 Oct 2008 11:49:51 GMT"
},
{
"version": "v4",
"created": "Thu, 19 Jul 2012 05:17:57 GMT"
},
{
"version": "v5",
"created": "Tue, 27 Aug 2013 14:33:09 GMT"
},
{
"version": "v6",
"created": "Wed, 29 Aug 2018 06:14:33 GMT"
}
] | 2018-08-30T00:00:00 |
[
[
"Cohen",
"Doron",
""
]
] |
quant-ph/0605181
|
Itai Arad
|
Dorit Aharonov and Itai Arad
|
The BQP-hardness of approximating the Jones Polynomial
|
36 pages, 8 figures. A much improved and revised version, updated to
Feb 2011, which includes discussions and implications of related results
published after the original 2006 version of this paper
|
New J. Phys. 13 (2011) 035019
|
10.1088/1367-2630/13/3/035019
| null |
quant-ph cs.CC
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A celebrated important result due to Freedman, Larsen and Wang states that
providing additive approximations of the Jones polynomial at the k'th root of
unity, for constant k=5 and k>6, is BQP-hard. Together with the algorithmic
results of Freedman et al and Aharonov et al, this gives perhaps the most
natural BQP-complete problem known today and motivates further study of the
topic. In this paper we focus on the universality proof; we extend the
universality result of Freedman et al to k's that grow polynomially with the
number of strands and crossings in the link, thus extending the BQP-hardness of
Jones polynomial approximations to all values for which the AJL algorithm
applies, proving that for all those values, the problems are BQP-complete. As a
side benefit, we derive a fairly elementary proof of the Freedman et al density
result, without referring to advanced results from Lie algebra representation
theory, making this important result accessible to computer science audience.
We make use of two general lemmas we prove, the Bridge lemma and the Decoupling
lemma, which provide tools for establishing density of subgroups in SU(n).
Those tools seem to be of independent interest in more general contexts of
proving quantum universality. Our result also implies a completely classical
statement, that the_multiplicative_ approximations of the Jones polynomial, at
exactly the same values, are #P-hard, via a recent result due to Kuperberg.
Since the first publication of those results in their preliminary form
(arXiv:quant-ph/0605181v2), the methods we present here were used in several
other contexts. This paper is an improved and extended version of the original
results, and also includes discussions of the developments since then.
|
[
{
"version": "v1",
"created": "Sun, 21 May 2006 21:39:38 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Oct 2006 10:28:24 GMT"
},
{
"version": "v3",
"created": "Mon, 13 Dec 2010 20:57:34 GMT"
},
{
"version": "v4",
"created": "Tue, 14 Dec 2010 19:25:11 GMT"
},
{
"version": "v5",
"created": "Sat, 19 Feb 2011 16:06:43 GMT"
}
] | 2011-03-28T00:00:00 |
[
[
"Aharonov",
"Dorit",
""
],
[
"Arad",
"Itai",
""
]
] |
quant-ph/0605182
|
Jonathan Barrett
|
Jonathan Barrett, Adrian Kent and Stefano Pironio
|
Maximally Non-Local and Monogamous Quantum Correlations
|
5 pages, no figures
|
Phys. Rev. Lett. 97, 170409 (2006).
|
10.1103/PhysRevLett.97.170409
| null |
quant-ph cs.CR
| null |
We introduce a version of the chained Bell inequality for an arbitrary number
of measurement outcomes, and use it to give a simple proof that the maximally
entangled state of two d dimensional quantum systems has no local component.
That is, if we write its quantum correlations as a mixture of local
correlations and general (not necessarily quantum) correlations, the
coefficient of the local correlations must be zero. This suggests an
experimental programme to obtain as good an upper bound as possible on the
fraction of local states, and provides a lower bound on the amount of classical
communication needed to simulate a maximally entangled state in dxd dimensions.
We also prove that the quantum correlations violating the inequality are
monogamous among non-signalling correlations, and hence can be used for quantum
key distribution secure against post-quantum (but non-signalling)
eavesdroppers.
|
[
{
"version": "v1",
"created": "Sun, 21 May 2006 22:57:16 GMT"
}
] | 2011-04-08T00:00:00 |
[
[
"Barrett",
"Jonathan",
""
],
[
"Kent",
"Adrian",
""
],
[
"Pironio",
"Stefano",
""
]
] |
quant-ph/0605183
|
Peter Rohde
|
Henry L. Haselgrove, Peter P. Rohde
|
Trade-off between the tolerance of located and unlocated errors in
nondegenerate quantum error-correcting codes
|
6 pages, 3 figures, significant update, tighter bound proven
|
QIC 8, 0399 (2008)
| null | null |
quant-ph
| null |
In a recent study [Rohde et al., quant-ph/0603130 (2006)] of several quantum
error correcting protocols designed for tolerance against qubit loss, it was
shown that these protocols have the undesirable effect of magnifying the
effects of depolarization noise. This raises the question of which general
properties of quantum error-correcting codes might explain such an apparent
trade-off between tolerance to located and unlocated error types. We extend the
counting argument behind the well-known quantum Hamming bound to derive a bound
on the weights of combinations of located and unlocated errors which are
correctable by nondegenerate quantum codes. Numerical results show that the
bound gives an excellent prediction to which combinations of unlocated and
located errors can be corrected with high probability by certain large
degenerate codes. The numerical results are explained partly by showing that
the generalized bound, like the original, is closely connected to the
information-theoretic quantity the quantum coherent information. However, we
also show that as a measure of the exact performance of quantum codes, our
generalized Hamming bound is provably far from tight.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 03:20:41 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jul 2007 11:33:55 GMT"
}
] | 2008-05-19T00:00:00 |
[
[
"Haselgrove",
"Henry L.",
""
],
[
"Rohde",
"Peter P.",
""
]
] |
quant-ph/0605184
|
Xiaoyu Chen
|
Xiao-Yu Chen, Li-zhen Jiang, Liang Han
|
The entanglement of damped noon-state and its performance in phase
measurement
|
8 pages, 2 figures
| null | null | null |
quant-ph
| null |
The state evolution of the initial optical \textit{noon} state is
investigated. The residue entanglement of the state is calculated after it is
damped by amplitude and phase damping. The relative entropy of entanglement of
the damped state is exactly obtained. The performance of direct application of
the damped \textit{noon} state is compared with that of firstly distilling the
docoherence damped state then applying it in measurement.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 03:24:32 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Chen",
"Xiao-Yu",
""
],
[
"Jiang",
"Li-zhen",
""
],
[
"Han",
"Liang",
""
]
] |
quant-ph/0605185
|
Indranil Chakrabarty ic
|
Indranil Chakrabarty
|
Single qubit, two qubit gates and no signalling principle
|
14 pages, Accepted in Romanian journal of Physics
|
Romanian Journal of Physics, Vol-54, No3-4 (2009)
| null | null |
quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work we investigate that whether one can construct single and two
qubit gates for arbitrary quantum states from the principle of no signalling.
We considered the problem for Pauli gates, Hadamard gate, C-Not gate.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 04:58:04 GMT"
},
{
"version": "v2",
"created": "Mon, 13 Nov 2006 15:16:50 GMT"
},
{
"version": "v3",
"created": "Sat, 31 Jan 2009 07:11:34 GMT"
}
] | 2009-03-10T00:00:00 |
[
[
"Chakrabarty",
"Indranil",
""
]
] |
quant-ph/0605186
|
Indranil Chakrabarty ic
|
Indranil Chakrabarty, Satyabrata Adhikari, B.S. Choudhury
|
Revisiting impossible quantum operations using principle of
no-signalling and non increase of entanglement under LOCC
|
4 pages, Accepted in International Journal of Theoretical Physics
|
IJTP,Volume 46, Number 10, 2007
|
10.1007/s10773-007-9366-6
| null |
quant-ph
| null |
In this letter, we show the impossibility of the general operation introduced
by Pati [3] using two different but consistent principles (i) no-signalling
(ii) non increase of entanglement under LOCC.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 05:11:09 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Oct 2006 08:56:52 GMT"
},
{
"version": "v3",
"created": "Fri, 23 Feb 2007 16:02:18 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Chakrabarty",
"Indranil",
""
],
[
"Adhikari",
"Satyabrata",
""
],
[
"Choudhury",
"B. S.",
""
]
] |
quant-ph/0605187
|
Eliahu Comay
|
E. Comay
|
The Significance of Density in the Structure of Quantum Theories
|
12 pages, no figure
| null | null |
TAUP 2833-2006
|
quant-ph
| null |
It is proved that density plays a crucial role in the structure of quantum
field theory. The Dirac and the Klein-Gordon equations are examined. The
results prove that the Dirac equation is consistent with density related
requirements whereas the Klein-Gordon equation fails to do that. Experimental
data support these conclusions.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 08:05:56 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Comay",
"E.",
""
]
] |
quant-ph/0605188
|
Jing Cheng
|
Minghui Zhang, Qing Wei, Xia Shen, Yongfeng Liu, Honglin Liu, Jing
Cheng, Shensheng Han
|
Lensless Fourier-Transform Ghost Imaging with Classical Incoherent Light
|
14 pages, 4 figures, comments are welcome
| null |
10.1103/PhysRevA.75.021803
| null |
quant-ph
| null |
The Fourier-Transform ghost imaging of both amplitude-only and pure-phase
objects was experimentally observed with classical incoherent light at Fresnel
distance by a new lensless scheme. The experimental results are in good
agreement with the standard Fourier-transform of the corresponding objects.
This scheme provides a new route towards aberration-free diffraction-limited 3D
images with classically incoherent thermal light, which have no resolution and
depth-of-field limitations of lens-based tomographic systems.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 08:43:49 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Zhang",
"Minghui",
""
],
[
"Wei",
"Qing",
""
],
[
"Shen",
"Xia",
""
],
[
"Liu",
"Yongfeng",
""
],
[
"Liu",
"Honglin",
""
],
[
"Cheng",
"Jing",
""
],
[
"Han",
"Shensheng",
""
]
] |
quant-ph/0605189
|
Sergey Maksimenko
|
G.Ya. Slepyan and S.A. Maksimenko
|
Photon statistics dispersion in excitonic composites
|
12 pages
| null | null | null |
quant-ph
| null |
Linear media are predicted to exist whose relative permiability is an
operator in the space of quantum states of light. Such media are characterized
by a photon statistics--dependent refractive index. This indicates a new type
of optical dispersion -- the photon statistics dispersion. Interaction of
quantum light with such media modifies the photon number distribution and, in
particular, the degree of coherence of light. An excitonic composite -- a
collection of noninteracting quantum dots -- is considered as a realization of
the medium with the photon statistics dispersion. Expressions are derived for
generalized plane waves in an excitonic composite and input--output relations
for a planar layer of the material. Transformation rules for different photon
initial states are analyzed. Utilization of the photon statistics dispersion in
potential quantum--optical devices is discussed.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 08:48:42 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Slepyan",
"G. Ya.",
""
],
[
"Maksimenko",
"S. A.",
""
]
] |
quant-ph/0605190
|
Peter Blythe
|
P. Blythe, B. Varcoe
|
Quantum Computing Using Crossed Atomic Beams
|
13 pages, 3 figures. PACS: 32.80.Qk, 42.50.Pq, 03.67.Lx
| null | null | null |
quant-ph
| null |
A quantum computer is a hypothetical device in which the laws of quantum
mechanics are used to introduce a degree of parallelism into computations and
which could therefore significantly improve on the computational speed of a
classical computer at certain tasks. Cluster state quantum computing (recently
proposed by Raussendorf and Briegel) is a new paradigm in quantum information
processing and is a departure from the conventional model of quantum
computation. The cluster state quantum computer begins by creating a highly
entangled multi-particle state (the cluster state) which it uses as a quantum
resource during the computation. Information is processed in the computer via
selected measurements on individual qubits that form the cluster state. We
describe in detail how a scalable quantum computer can be constructed using
microwave cavity QED and, in a departure from the traditional understanding of
a computer as a fixed array of computational elements, we show that cluster
state quantum computing is well suited to atomic beam experiments. We show that
all of the necessary elements have been individually realised, and that the
construction of a truly scalable atomic beam quantum computer may be an
experimental reality in the near future.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 10:54:05 GMT"
},
{
"version": "v2",
"created": "Tue, 23 May 2006 13:44:07 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Blythe",
"P.",
""
],
[
"Varcoe",
"B.",
""
]
] |
quant-ph/0605191
|
Archan S. Majumdar
|
Biplab Ghosh, A. S. Majumdar, N. Nayak
|
Atomic entanglement mediated by a squeezed cavity field
|
6 pages, 7 eps figures
|
Int. J Theor. Phys. 12, 2 (2007)
| null | null |
quant-ph
| null |
We consider the coherent state radiation field inside a micromaser cavity and
study the entanglement mediated by it on a pair of two level atoms passing
though the cavity one after the other. We then investigate the effects of
squeezing of the cavity field on the atomic entanglement. We compute the
entanglement of formation for the emerging mixed two-atom state and show that
squeezing of the cavity radiation field can increase the atomic entanglement.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 12:06:26 GMT"
}
] | 2007-11-26T00:00:00 |
[
[
"Ghosh",
"Biplab",
""
],
[
"Majumdar",
"A. S.",
""
],
[
"Nayak",
"N.",
""
]
] |
quant-ph/0605192
|
Bryan Eastin
|
Bryan Eastin
|
Fault-Tolerant Thresholds for Encoded Ancillae with Homogeneous Errors
|
14 pages, 5 figures, 3 tables; v2 minor edits, v3 completely revised,
submitted to PRA
|
Phys. Rev. A, 75, 022301 (2007)
|
10.1103/PhysRevA.75.022301
| null |
quant-ph
| null |
I describe a procedure for calculating thresholds for quantum computation as
a function of error model given the availability of ancillae prepared in
logical states with independent, identically distributed errors. The thresholds
are determined via a simple counting argument performed on a single qubit of an
infinitely large CSS code. I give concrete examples of thresholds thus
achievable for both Steane and Knill style fault-tolerant implementations and
investigate their relation to threshold estimates in the literature.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 14:23:14 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Jun 2006 02:38:47 GMT"
},
{
"version": "v3",
"created": "Tue, 14 Nov 2006 02:18:25 GMT"
}
] | 2009-11-16T00:00:00 |
[
[
"Eastin",
"Bryan",
""
]
] |
quant-ph/0605193
|
Diego Arb\'o
|
Diego Arbo, Emil Persson, Joachim Burgdoerfer
|
Time Double-Slit Interference in Tunneling Ionization
|
7 pages, 5 figures
| null |
10.1103/PhysRevA.74.063407
| null |
quant-ph
| null |
We show that interference phenomena plays a big role for the electron yield
in ionization of atoms by an ultra-short laser pulse. Our theoretical study of
single ionization of atoms driven by few-cycles pulses extends the
photoelectron spectrum observed in the double-slit experiment by Lindner et al,
Phys. Rev. Lett. \textbf{95}, 040401 (2005) to a complete three-dimensional
momentum picture. We show that different wave packets corresponding to the same
single electron released at different times interfere, forming interference
fringes in the two-dimensional momentum distributions. These structures
reproduced by means of \textit{ab initio} calculations are understood within a
semiclassical model.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 14:36:14 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Arbo",
"Diego",
""
],
[
"Persson",
"Emil",
""
],
[
"Burgdoerfer",
"Joachim",
""
]
] |
quant-ph/0605194
|
Robert J. C. Spreeuw
|
T.W. Hijmans, T.N. Huussen, and R.J.C. Spreeuw
|
Time and frequency domain solutions in an optical analogue of Grover's
search algorithm
|
16 pages in preprint format, 6 figures v2: some minor revisions
|
J. Opt. Soc. Am. B 24, 214 (2007)
|
10.1364/JOSAB.24.000214
| null |
quant-ph
| null |
We present new results on an optical implementation of Grover's quantum
search algorithm. This extends previous work in which the transverse spatial
mode of a light beam oscillates between a broad initial input shape and a
highly localized spike, which reveals the position of the tagged item. The
spike reaches its maximum intensity after $\sim\sqrt N$ round trips in a cavity
equipped with two phase plates, where $N$ is the ratio of the surface area of
the original beam and the area of the phase spot or tagged item. In our
redesigned experiment the search space is now two-dimensional. In the time
domain we demonstrate for the first time a multiple item search where the items
appear directly as bright spots on the images of a gated camera. In a
complementary experiment we investigate the searching cavity in the frequency
domain. The oscillatory nature of the search algorithm can be seen as a
splitting of cavity eigenmodes, each of which concentrates up to 50% of its
power in the bright spot corresponding to the solution.
|
[
{
"version": "v1",
"created": "Mon, 22 May 2006 15:32:09 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Sep 2006 16:01:55 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Hijmans",
"T. W.",
""
],
[
"Huussen",
"T. N.",
""
],
[
"Spreeuw",
"R. J. C.",
""
]
] |
quant-ph/0605195
|
Anthony John Bracken
|
A.J. Bracken, D. Ellinas and I. Smyrnakis
|
Free Dirac evolution as a quantum random walk
|
16 pages, 1 figure. Latex2e file
| null |
10.1103/PhysRevA.75.022322
| null |
quant-ph
| null |
Any positive-energy state of a free Dirac particle that is initially
highly-localized, evolves in time by spreading at speeds close to the speed of
light. This general phenomenon is explained by the fact that the Dirac
evolution can be approximated arbitrarily closely by a quantum random walk,
where the roles of coin and walker systems are naturally attributed to the spin
and position degrees of freedom of the particle. Initially entangled and
spatially localized spin-position states evolve with asymptotic two-horned
distributions of the position probability, familiar from earlier studies of
quantum walks. For the Dirac particle, the two horns travel apart at close to
the speed of light.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 00:42:05 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Bracken",
"A. J.",
""
],
[
"Ellinas",
"D.",
""
],
[
"Smyrnakis",
"I.",
""
]
] |
quant-ph/0605196
|
Yi-Xin Chen
|
Lin Chen and Yi-Xin Chen
|
Classification of GHZ-type, W-type and GHZ-W-type multiqubit
entanglements
|
16 pages, Revtex
| null |
10.1103/PhysRevA.74.062310
| null |
quant-ph
| null |
We propose the concept of SLOCC-equivalent basis (SEB) in the multiqubit
space. In particular, two special SEBs, the GHZ-type and the W-type basis are
introduced. They can make up a more general family of multiqubit states, the
GHZ-W-type states, which is a useful kind of entanglement for quantum
teleporatation and error correction. We completely characterize the property of
this type of states, and mainly classify the GHZ-type states and the W-type
states in a regular way, which is related to the enumerative combinatorics.
Many concrete examples are given to exhibit how our method is used for the
classification of these entangled states.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 06:13:30 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Chen",
"Lin",
""
],
[
"Chen",
"Yi-Xin",
""
]
] |
quant-ph/0605197
|
Daniel Burgarth
|
Daniel Burgarth and Vittorio Giovannetti
|
The Generalized Lyapunov Theorem and its Application to Quantum Channels
|
13 pages, 3 figures
|
New J. Phys. 9 150 (2007)
|
10.1088/1367-2630/9/5/150
| null |
quant-ph math-ph math.MP
| null |
We give a simple and physically intuitive necessary and sufficient condition
for a map acting on a compact metric space to be mixing (i.e. infinitely many
applications of the map transfer any input into a fixed convergency point).
This is a generalization of the "Lyapunov direct method". First we prove this
theorem in topological spaces and for arbitrary continuous maps. Finally we
apply our theorem to maps which are relevant in Open Quantum Systems and
Quantum Information, namely Quantum Channels. In this context we also discuss
the relations between mixing and ergodicity (i.e. the property that there exist
only a single input state which is left invariant by a single application of
the map) showing that the two are equivalent when the invariant point of the
ergodic map is pure.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 19:54:40 GMT"
},
{
"version": "v2",
"created": "Fri, 9 Jun 2006 10:29:26 GMT"
},
{
"version": "v3",
"created": "Fri, 9 Mar 2007 15:38:58 GMT"
}
] | 2007-06-13T00:00:00 |
[
[
"Burgarth",
"Daniel",
""
],
[
"Giovannetti",
"Vittorio",
""
]
] |
quant-ph/0605198
|
Nicolas Menicucci
|
Nicolas C. Menicucci, Peter van Loock, Mile Gu, Christian Weedbrook,
Timothy C. Ralph, Michael A. Nielsen
|
Universal Quantum Computation with Continuous-Variable Cluster States
|
4 pages, no figures
|
Phys. Rev. Lett. 97, 110501 (2006)
|
10.1103/PhysRevLett.97.110501
| null |
quant-ph
| null |
We describe a generalization of the cluster-state model of quantum
computation to continuous-variable systems, along with a proposal for an
optical implementation using squeezed-light sources, linear optics, and
homodyne detection. For universal quantum computation, a nonlinear element is
required. This can be satisfied by adding to the toolbox any single-mode
non-Gaussian measurement, while the initial cluster state itself remains
Gaussian. Homodyne detection alone suffices to perform an arbitrary multi-mode
Gaussian transformation via the cluster state. We also propose an experiment to
demonstrate cluster-based error reduction when implementing Gaussian
operations.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 14:15:55 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Menicucci",
"Nicolas C.",
""
],
[
"van Loock",
"Peter",
""
],
[
"Gu",
"Mile",
""
],
[
"Weedbrook",
"Christian",
""
],
[
"Ralph",
"Timothy C.",
""
],
[
"Nielsen",
"Michael A.",
""
]
] |
quant-ph/0605199
|
Sahin Kaya Ozdemir Dr
|
Y. Hirayama, A. Miranowicz, T. Ota, G. Yusa, K. Muraki, S. K. Ozdemir,
and N. Imoto
|
Nanometre-scale nuclear-spin device for quantum information processing
|
16 pages, 5 figures
|
J. Phys.: Condens. Matter 18 (2006) S885-S900
|
10.1088/0953-8984/18/21/S13
| null |
quant-ph cond-mat.mes-hall
| null |
We have developed semiconductor point contact devices in which nuclear spins
in a nanoscale region are coherently controlled by all-electrical methods.
Different from the standard nuclear-magnetic resonance technique, the
longitudinal magnetization of nuclear spins is directly detected by measuring
resistance, resulting in ultra-sensitive detection of the microscopic quantity
of nuclear spins. All possible coherent oscillations have been successfully
demonstrated between two levels from four nuclear spin states of I = 3/2
nuclei. Quantum information processing is discussed based on two fictitious
qubits of an I = 3/2 system and methods are described for performing arbitrary
logical gates both on one and two qubits. A scheme for quantum state tomography
based on Mz-detection is also proposed. As the starting point of quantum
manipulations, we have experimentally prepared the effective pure states for
the I = 3/2 nuclear spin system.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 14:19:36 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Hirayama",
"Y.",
""
],
[
"Miranowicz",
"A.",
""
],
[
"Ota",
"T.",
""
],
[
"Yusa",
"G.",
""
],
[
"Muraki",
"K.",
""
],
[
"Ozdemir",
"S. K.",
""
],
[
"Imoto",
"N.",
""
]
] |
quant-ph/0605200
|
Anita Dabrowska
|
Anita Dabrowska
|
Continuous observation of a squeezed coherent state
|
Author changed and enlarged this article and post as Squeezed
coherent state undergoing a continuous nondemolition observation
| null | null | null |
quant-ph
| null |
The main aim of the paper is to present the analytical solution of the
Belavkin quantum filtering equation for damped harmonic oscillator being
initially in the squeezed coherent state for diffusion observation with complex
white noise. The comparison of the a priori and a posteriori mean value of the
optical quadrature operators and the photon number operator is given.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 16:31:02 GMT"
},
{
"version": "v2",
"created": "Mon, 9 Jul 2012 17:14:31 GMT"
}
] | 2012-07-10T00:00:00 |
[
[
"Dabrowska",
"Anita",
""
]
] |
quant-ph/0605201
|
Mikhail Lukin
|
A.Andre, D.DeMille, J.M.Doyle, M.D.Lukin, S.E.Maxwell, P.Rabl,
R.Schoelkopf, P.Zoller
|
Polar molecules near superconducting resonators: a coherent,
all-electrical, molecule-mesoscopic interface
| null | null | null | null |
quant-ph cond-mat.supr-con
| null |
The challenge of building a scalable quantum processor requires consolidation
of the conflicting requirements of achieving coherent control and preservation
of quantum coherence in a large scale quantum system. Moreover, the system
should be compatible with miniaturization and integration of quantum circuits.
Mesoscopic solid state systems such as superconducting islands and quantum dots
feature robust control techniques using local electrical signals and
self-evident scaling based on advances in fabrication; however, in general the
quantum states of solid state devices tend to decohere rapidly. In contrast,
quantum optical systems based on trapped ions and neutral atoms exhibit
dramatically better coherence properties, while miniaturization of atomic and
molecular systems, and their integration with mesoscopic electrical circuits,
remains an important challenge. Below we describe methods for the integration
of a single particle system -- an isolated polar molecule -- with mesoscopic
solid state devices in a way that produces robust, coherent, quantum-level
control. The methods described include the trapping, cooling, detection,
coherent manipulation and quantum coupling of isolated polar molecules at
sub-micron dimensions near cryogenic stripline microwave resonators. We show
that electrostatically trapped polar molecules can exhibit strong confinement
and fast, purely electrical gate control. Furthermore, the effect of electrical
noise sources, a key issue in quantum information processing, can be suppressed
to very low levels via appropriate preparation and manipulation of the polar
molecules. Our setup provides a scalable cavity QED-type quantum computer
architecture, where entanglement of distant qubits stored in long-lived
rotational molecular states is achieved via exchange of microwave photons.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 20:23:00 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Andre",
"A.",
""
],
[
"DeMille",
"D.",
""
],
[
"Doyle",
"J. M.",
""
],
[
"Lukin",
"M. D.",
""
],
[
"Maxwell",
"S. E.",
""
],
[
"Rabl",
"P.",
""
],
[
"Schoelkopf",
"R.",
""
],
[
"Zoller",
"P.",
""
]
] |
quant-ph/0605202
|
Han Pu
|
Han Pu, Peter Maenner, Weiping Zhang, and Hong Y. Ling
|
Adiabatic Condition for Nonlinear Systems
|
4 pages, 3 figures
| null |
10.1103/PhysRevLett.98.050406
| null |
quant-ph
| null |
We revisit the adiabatic criterion in stimulated Raman adiabatic passage for
the three-level $\Lambda$-system, and compare the situation with and without
nonlinearity. In linear systems, the adiabatic condition is derived with the
help of the instantaneous eigenvalues and eigenstates of the Hamiltonian, a
procedure that breaks down in the presence of nonlinearity. Using an explicit
example relevant to photoassociation of atoms into diatomic molecules, we
demonstrate that the proper way to derive the adiabatic condition for the
nonlinear systems is through a linearization procedure.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 22:37:44 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Pu",
"Han",
""
],
[
"Maenner",
"Peter",
""
],
[
"Zhang",
"Weiping",
""
],
[
"Ling",
"Hong Y.",
""
]
] |
quant-ph/0605203
|
Jian-Ming Tang
|
Jian-Ming Tang, Jeremy Levy, and Michael E. Flatte
|
All-electrical control of single ion spins in a semiconductor
|
5 pages, 3 figures
|
Phys. Rev. Lett. 97, 106803 (2006)
|
10.1103/PhysRevLett.97.106803
| null |
quant-ph cond-mat.mtrl-sci
| null |
We propose a method for all-electrical initialization, control and readout of
the spin of single ions substituted into a semiconductor. Mn ions in GaAs form
a natural example. In the ion's ground state the Mn core spin magnetic moment
locks antiparallel to the spin and orbital magnetic moment of a bound valence
hole from the GaAs host. Direct electrical manipulation of the ion spin is
possible because electric fields manipulate the orbital wave function of the
hole, and through the spin-orbit coupling the spin is reoriented as well.
Coupling two or more ion spins can be achieved using electrical gates to
control the size of the valence hole wave function near the semiconductor
surface. This proposal for coherent manipulation of individual ionic spins and
controlled coupling of ionic spins via electrical gates alone may find
applications in extremely high density information storage and in scalable
coherent or quantum information processing.
|
[
{
"version": "v1",
"created": "Tue, 23 May 2006 23:49:51 GMT"
},
{
"version": "v2",
"created": "Tue, 5 Sep 2006 17:40:16 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Tang",
"Jian-Ming",
""
],
[
"Levy",
"Jeremy",
""
],
[
"Flatte",
"Michael E.",
""
]
] |
quant-ph/0605204
|
Cunbing Huang
|
Xin-Wei Zha, Cun-Bing Huang
|
The complete basis with an unextendible product basis and
exact-entanglement bases (CBUPB) of three qubit
|
9 pages
| null | null | null |
quant-ph
| null |
In this paper, an unextendible product basis and exact-entanglement bases of
three qubit is given, and the properties of entanglement for exact-entanglement
bases are also discussed. In addition, the bound entangled mixed state is
obtained from the exact-entanglement bases.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 05:43:59 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Zha",
"Xin-Wei",
""
],
[
"Huang",
"Cun-Bing",
""
]
] |
quant-ph/0605205
|
Hank Miller
|
W. A. Berger and H. G. Miller
|
Improving the Convergence of an Iterative Algorithm Proposed By Waxman
| null | null |
10.1088/0305-4470/39/45/016
| null |
quant-ph math-ph math.MP
| null |
In the iterative algorithm recently proposed by Waxman for solving eigenvalue
problems, we point out that the convergence rate may be improved. For many
non-singular symmetric potentials which vanish asymptotically, a simple
analytical relationship between the coupling constant of the potential and the
ground state eigenvalue is obtained which can be used to make the algorithm
more efficient.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 07:51:16 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Berger",
"W. A.",
""
],
[
"Miller",
"H. G.",
""
]
] |
quant-ph/0605206
|
Teng-Yun Chen
|
Teng-Yun Chen, Jun Zhang, J.-C. Boileau, Xian-Min Jin, Bin Yang, Qiang
Zhang, Tao Yang, R. Laflamme, and Jian-Wei Pan
|
Experimental Quantum Communication without a Shared Reference Frame
|
4 pages, 4 figures
|
Phys.Rev.Lett. 96, 150504 (2006)
|
10.1103/PhysRevLett.96.150504
| null |
quant-ph
| null |
We present an experimental realization of a robust quantum communication
scheme [Phys. Rev. Lett. 93, 220501 (2004)] using pairs of photons entangled in
polarization and time. Our method overcomes errors due to collective rotation
of the polarization modes (e.g., birefringence in optical fiber or
misalignment), is insensitive to the phase's fluctuation of the interferometer,
and does not require any shared reference frame including time reference,
except the need to label different photons. The practical robustness of the
scheme is further shown by implementing a variation of the Bennett-Brassard
1984 quantum key distribution protocol over 1 km optical fiber.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 10:47:03 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 03:37:33 GMT"
}
] | 2007-06-13T00:00:00 |
[
[
"Chen",
"Teng-Yun",
""
],
[
"Zhang",
"Jun",
""
],
[
"Boileau",
"J. -C.",
""
],
[
"Jin",
"Xian-Min",
""
],
[
"Yang",
"Bin",
""
],
[
"Zhang",
"Qiang",
""
],
[
"Yang",
"Tao",
""
],
[
"Laflamme",
"R.",
""
],
[
"Pan",
"Jian-Wei",
""
]
] |
quant-ph/0605207
|
Eugeniy Mikhailov
|
Eugeniy E. Mikhailov, Keisuke Goda, Nergis Mavalvala
|
Non-invasive Measurements of Cavity Parameters by Use of Squeezed Vacuum
|
6 pages, 4 figures
|
Phys. Rev. A 74, 033817 (2006)
|
10.1103/PhysRevA.74.033817
| null |
quant-ph
| null |
We propose and experimentally demonstrate a method for non-invasive
measurements of cavity parameters by injection of squeezed vacuum into an
optical cavity. The principle behind this technique is the destruction of the
correlation between upper and lower quantum sidebands with respect to the
carrier frequency when the squeezed field is incident on the cavity. This
method is especially useful for ultrahigh $Q$ cavities, such as whispering
gallery mode (WGM) cavities, in which absorption and scattering by
light-induced nonlinear processes inhibit precise measurements of the cavity
parameters. We show that the linewidth of a test cavity is measured to be
$\gamma = 844\pm40$ kHz, which agrees with the classically measured linewidth
of the cavity within the uncertainty ($\gamma=856\pm34$ kHz).
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 13:36:12 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Jul 2006 21:55:52 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Mikhailov",
"Eugeniy E.",
""
],
[
"Goda",
"Keisuke",
""
],
[
"Mavalvala",
"Nergis",
""
]
] |
quant-ph/0605208
|
Yurii Ivanovich Bogdanov
|
A.Yu. Bogdanov, Yu.I. Bogdanov, K.A. Valiev
|
Entanglement of Quantum States, Thermodynamical Statistical
Distributions and Physical Nature of Temperature
|
11 pages, 2 figure, a report for the XI International Conference on
Quantum Optics (ICQO-2006), May 26-31, 2006, Minsk, Belarus
| null | null | null |
quant-ph cond-mat.stat-mech physics.data-an
| null |
Thermodynamical equilibrium is considered as an effect of quantum entangling
of the vacuum state of a system. An explicit mathematical model of multi-
particle entangled pure quantum states is developed and analyzed. In the
framework, the process of measurement results in probability distributions that
exactly correspond to the heat equilibrium of a system in a thermostat.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 13:44:44 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Bogdanov",
"A. Yu.",
""
],
[
"Bogdanov",
"Yu. I.",
""
],
[
"Valiev",
"K. A.",
""
]
] |
quant-ph/0605209
|
Miloslav Znojil
|
Miloslav Znojil
|
Matching method and exact solvability of discrete PT-symmetric square
wells
|
25 pp, 3 figures
|
J.Phys. A39 (2006) 10247
|
10.1088/0305-4470/39/32/S23
| null |
quant-ph
| null |
Discrete PT-symmetric square wells are studied. Their wave functions are
found proportional to classical Tshebyshev polynomials of complex argument. The
compact secular equations for energies are derived giving the real spectra in
certain intervals of non-Hermiticity strengths Z. It is amusing to notice that
although the known square well re-emerges in the usual continuum limit, a twice
as rich, upside-down symmetric spectrum is exhibited by all its present
discretized predecessors.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 13:48:33 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Znojil",
"Miloslav",
""
]
] |
quant-ph/0605210
|
Sascha Z\"ollner
|
Sascha Z\"ollner, Hans-Dieter Meyer, and Peter Schmelcher
|
Ultracold Few-Boson Systems in a Double-Well Trap
| null |
Phys. Rev. A 74, 053612 (2006)
|
10.1103/PhysRevA.74.053612
| null |
quant-ph cond-mat.other
| null |
We investigate the transition of a quasi-one-dimensional few-boson system
from a weakly correlated to a fragmented and finally a fermionized ground
state. Our numerically exact analysis, based on a multi-configurational method,
explores the interplay between different shapes of external and inter-particle
forces. Specifically, we demonstrate that the addition of a central barrier to
an otherwise harmonic trap may supports the system's fragmentation, with a
symmetry-induced distinction between even and odd atom numbers. Moreover, the
impact of inhomogeneous interactions is studied, where the effective coupling
strength is spatially modulated. It is laid out how the ground state can be
displaced in a controlled way depending on the trap and the degree of
modulation. We present the one- and two-body densities and, beyond that,
highlight the role of correlations on the basis of the natural occupations.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 14:20:11 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Zöllner",
"Sascha",
""
],
[
"Meyer",
"Hans-Dieter",
""
],
[
"Schmelcher",
"Peter",
""
]
] |
quant-ph/0605211
|
Aurelien Drezet
|
Aurelien Drezet, Andreas Hohenau, Joachim R. Krenn
|
Momentum transfer for momentum transfer-free which-path experiments
|
to appear in Phys. Rev . A (2006). (7 pages, 2 figures)
| null |
10.1103/PhysRevA.73.062112
| null |
quant-ph
| null |
We analyze the origin of interference disappearance in which-path double
aperture experiments. We show that we can unambiguously define an observable
momentum transfer between the quantum particle and the path detector and we
prove in particular that the so called ``momentum transfer free'' experiments
can be in fact logically interpreted in term of momentum transfer.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 15:33:19 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Drezet",
"Aurelien",
""
],
[
"Hohenau",
"Andreas",
""
],
[
"Krenn",
"Joachim R.",
""
]
] |
quant-ph/0605212
|
Mark Tame
|
M. S. Tame, M. Paternostro, C. Hadley, S. Bose, M. S. Kim
|
Decoherence-based exploration of d-dimensional one-way quantum
computation
|
8 pages, 11 figures, RevTeX 4
|
Phys. Rev. A 74, 042330 (2006)
|
10.1103/PhysRevA.74.042330
| null |
quant-ph cond-mat.other
| null |
We study the effects of amplitude and phase damping decoherence in
d-dimensional one-way quantum computation (QC). Our investigation shows how
information transfer and entangling gate simulations are affected for d>=2. To
understand motivations for extending the one-way model to higher dimensions, we
describe how d-dimensional qudit cluster states deteriorate under environmental
noise. In order to protect quantum information from the environment we consider
the encoding of logical qubits into physical qudits and compare entangled pairs
of linear qubit-cluster states with single qudit clusters of equal length and
total dimension. Our study shows a significant reduction in the performance of
one-way QC for d>2 in the presence of Markovian type decoherence models.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 15:57:54 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Tame",
"M. S.",
""
],
[
"Paternostro",
"M.",
""
],
[
"Hadley",
"C.",
""
],
[
"Bose",
"S.",
""
],
[
"Kim",
"M. S.",
""
]
] |
quant-ph/0605213
|
Takayuki Miyadera
|
Takayuki Miyadera, Hideki Imai
|
Wigner-Araki-Yanase theorem on Distinguishability
|
To be published in Phys.Rev.A
|
Phys.Rev.A 74, 024101 (2006)
|
10.1103/PhysRevA.74.024101
| null |
quant-ph
| null |
The presence of an additive conserved quantity imposes a limitation on the
measurement process. According to the Wigner-Araki-Yanase theorem, the perfect
repeatability and the distinguishability on the apparatus cannot be attained
simultaneously. Instead of the repeatability, in this paper, the
distinguishability on both systems is examined. We derive a trade-off
inequality between the distinguishability of the final states on the system and
the one on the apparatus. The inequality shows that the perfect
distinguishability of both systems cannot be attained simultaneously.
|
[
{
"version": "v1",
"created": "Wed, 24 May 2006 16:20:28 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Jul 2006 16:15:19 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Miyadera",
"Takayuki",
""
],
[
"Imai",
"Hideki",
""
]
] |
quant-ph/0605214
|
Fu-Guo Deng
|
Fu-Guo Deng, Xi-Han Li, Chun-Yan Li, Ping Zhou and Hong-Yu Zhou
|
Quantum secure direct communication network with superdense coding and
decoy photons
|
6 pages, 2 figure
|
Physcica Scripta 76 (2007) 25-30
|
10.1088/0031-8949/76/1/005
| null |
quant-ph
| null |
A quantum secure direct communication network scheme is proposed with quantum
superdense coding and decoy photons. The servers on a passive optical network
prepare and measure the quantum signal, i.e., a sequence of the $d$-dimensional
Bell states. After confirming the security of the photons received from the
receiver, the sender codes his secret message on them directly. For preventing
a dishonest server from eavesdropping, some decoy photons prepared by measuring
one photon in the Bell states are used to replace some original photons. One of
the users on the network can communicate any other one. This scheme has the
advantage of high capacity, and it is more convenient than others as only a
sequence of photons is transmitted in quantum line.
|
[
{
"version": "v1",
"created": "Thu, 25 May 2006 05:38:27 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 10:34:39 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Deng",
"Fu-Guo",
""
],
[
"Li",
"Xi-Han",
""
],
[
"Li",
"Chun-Yan",
""
],
[
"Zhou",
"Ping",
""
],
[
"Zhou",
"Hong-Yu",
""
]
] |
quant-ph/0605215
|
Ryu Sasaki
|
Satoru Odake and Ryu Sasaki
|
Unified Theory of Annihilation-Creation Operators for Solvable
(`Discrete') Quantum Mechanics
|
43 pages, no figures, LaTeX2e, with amsmath, amssymb
|
J.Math.Phys. 47 (2006) 102102
|
10.1063/1.2349485
|
DPSU-06-1, YITP-06-23
|
quant-ph hep-th math-ph math.CA math.MP nlin.SI
| null |
The annihilation-creation operators $a^{(\pm)}$ are defined as the
positive/negative frequency parts of the exact Heisenberg operator solution for
the `sinusoidal coordinate'. Thus $a^{(\pm)}$ are hermitian conjugate to each
other and the relative weights of various terms in them are solely determined
by the energy spectrum. This unified method applies to most of the solvable
quantum mechanics of single degree of freedom including those belonging to the
`discrete' quantum mechanics.
|
[
{
"version": "v1",
"created": "Thu, 25 May 2006 07:45:15 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Odake",
"Satoru",
""
],
[
"Sasaki",
"Ryu",
""
]
] |
quant-ph/0605216
|
Caroline Vandenplas Ms
|
M. Fannes and C. Vandenplas
|
Finite size mean-field models
|
20 pages
| null |
10.1088/0305-4470/39/45/001
| null |
quant-ph
| null |
We characterize the two-site marginals of exchangeable states of a system of
quantum spins in terms of a simple positivity condition. This result is used in
two applications. We first show that the distance between two-site marginals of
permutation invariant states on N spins and exchangeable states is of order
1/N. The second application relates the mean ground state energy of a
mean-field model of composite spins interacting through a product pair
interaction with the mean ground state energies of the components.
|
[
{
"version": "v1",
"created": "Thu, 25 May 2006 09:12:46 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Fannes",
"M.",
""
],
[
"Vandenplas",
"C.",
""
]
] |
quant-ph/0605217
|
Marcel Novaes
|
J.P. Keating, M. Novaes, S.D. Prado, M. Sieber
|
Semiclassical structure of chaotic resonance eigenfunctions
|
4 pages, 4 figures; some minor corrections, some changes in
presentation
|
Phys. Rev. Lett. 97, 150406 (2006)
|
10.1103/PhysRevLett.97.150406
| null |
quant-ph nlin.CD
| null |
We study the resonance (or Gamow) eigenstates of open chaotic systems in the
semiclassical limit, distinguishing between left and right eigenstates of the
non-unitary quantum propagator, and also between short-lived and long-lived
states. The long-lived left (right) eigenstates are shown to concentrate as
$\hbar\to 0$ on the forward (backward) trapped set of the classical dynamics.
The limit of a sequence of eigenstates $\{\psi(\hbar)\}_{\hbar\to 0}$ is found
to exhibit a remarkably rich structure in phase space that depends on the
corresponding limiting decay rate. These results are illustrated for the open
baker map, for which the probability density in position space is observed to
have self-similarity properties.
|
[
{
"version": "v1",
"created": "Thu, 25 May 2006 16:12:02 GMT"
},
{
"version": "v2",
"created": "Wed, 16 Aug 2006 19:57:29 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Keating",
"J. P.",
""
],
[
"Novaes",
"M.",
""
],
[
"Prado",
"S. D.",
""
],
[
"Sieber",
"M.",
""
]
] |
quant-ph/0605218
|
Mingsheng Ying
|
Mingsheng Ying and Yuan Feng
|
Quantum loop programs
| null |
Acta Informatica 47(4): 221-250 (2010)
| null | null |
quant-ph
| null |
Loop is a powerful program construct in classical computation, but its power
is still not exploited fully in quantum computation. The exploitation of such
power definitely requires a deep understanding of the mechanism of quantum loop
programs. In this paper, we introduce a general scheme of quantum loops and
describe its computational process. The notions of termination and almost
termination are proposed for quantum loops, and the function computed by a
quantum loop is defined. To show their expressive power, quantum loops are
applied in describing quantum walks. Necessary and sufficient conditions for
termination and almost termination of a general quantum loop on any mixed input
state are presented. A quantum loop is said to be (almost) terminating if it
(almost) terminates on any input state. We show that a quantum loop is almost
terminating if and only if it is uniformly almost terminating. It is observed
that a small disturbance either on the unitary transformation in the loop body
or on the measurement in the loop guard can make any quantum loop (almost)
terminating. Moreover, a representation of the function computed by a quantum
loop is given in terms of finite summations of matrices. To illustrate the
notions and results obtained in this paper, two simplest classes of quantum
loop programs, one qubit quantum loops, and two qubit quantum loops defined by
controlled gates, are carefully examined.
|
[
{
"version": "v1",
"created": "Thu, 25 May 2006 14:05:29 GMT"
},
{
"version": "v2",
"created": "Thu, 4 Jan 2007 14:06:11 GMT"
}
] | 2013-04-02T00:00:00 |
[
[
"Ying",
"Mingsheng",
""
],
[
"Feng",
"Yuan",
""
]
] |
quant-ph/0605219
|
Alexander Yu. Vlasov
|
Alexander Yu. Vlasov
|
Classical simulators of quantum computers and no-go theorems
|
LaTeX, 22 pp, 7 fig, v2: small changes in text, refs, figs. Comments
are welcome
| null | null | null |
quant-ph cs.OH
| null |
It is discussed, why classical simulators of quantum computers escape from
some no-go claims like Kochen-Specker, Bell, or recent Conway-Kochen "Free
Will" theorems.
|
[
{
"version": "v1",
"created": "Thu, 25 May 2006 15:47:52 GMT"
},
{
"version": "v2",
"created": "Tue, 13 Jun 2006 12:44:57 GMT"
}
] | 2010-05-11T00:00:00 |
[
[
"Vlasov",
"Alexander Yu.",
""
]
] |
quant-ph/0605220
|
Xiaofei Huang
|
Xiaofei Huang
|
A Global Optimization Approach to Quantum Mechanics
| null | null | null |
Tsinghua-SIST-05-25-2006p
|
quant-ph
| null |
This paper presents a global optimization approach to quantum mechanics,
which describes the most fundamental dynamics of the universe. It suggests that
the wave-like behavior of (sub)atomic particles could be the critical
characteristic of a global optimization method deployed by nature so that
(sub)atomic systems can find their ground states corresponding to the global
minimum of some energy function associated with the system. The classic
time-independent Schrodinger equation is shown to be derivable from the global
optimization method to support this argument.
|
[
{
"version": "v1",
"created": "Thu, 25 May 2006 22:58:35 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Huang",
"Xiaofei",
""
]
] |
quant-ph/0605221
|
Satoru Odake
|
Satoru Odake and Ryu Sasaki
|
Exact solution in the Heisenberg picture and annihilation-creation
operators
|
10 pages, no figures. Abstract, Introduction revised; Conclusion
added; Document-class changed. To appear in Phys. Lett. B
|
Phys.Lett. B641 (2006) 112-117
|
10.1016/j.physletb.2006.08.017
|
DPSU-06-2, YITP-06-24
|
quant-ph hep-th math-ph math.CA math.MP nlin.SI
| null |
The annihilation-creation operators of the harmonic oscillator, the basic and
most important tools in quantum physics, are generalised to most solvable
quantum mechanical systems of single degree of freedom including the so-called
`discrete' quantum mechanics. They admit exact Heisenberg operator solution. We
present unified definition of the annihilation-creation operators (a^{(\pm)})
as the positive/negative frequency parts of the exact Heisenberg operator
solution.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 04:55:00 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Aug 2006 04:39:02 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Odake",
"Satoru",
""
],
[
"Sasaki",
"Ryu",
""
]
] |
quant-ph/0605222
|
Robert Collins
|
Karen J. Gordon, Veronica Fernandez, Paul D. Townsend, and Gerald S.
Buller
|
A Short Wavelength GigaHertz Clocked Fiber-Optic Quantum Key
Distribution System
|
Pre-press version
|
IEEE Journal of Quantum Electronics, Volume 40 (7), pp900-908
(2004)
|
10.1109/JQE.2004.830182
| null |
quant-ph
| null |
A quantum key distribution system has been developed, using standard
telecommunications optical fiber, which is capable of operating at clock rates
of greater than 1 GHz. The quantum key distribution system implements a
polarization encoded version of the B92 protocol. The system employs
vertical-cavity surface-emitting lasers with emission wavelengths of 850 nm as
weak coherent light sources, and silicon single photon avalanche diodes as the
single photon detectors. A distributed feedback laser of emission wavelength
1.3 micro-metres, and a linear gain germanium avalanche photodiode was used to
optically synchronize individual photons over the standard telecommunications
fiber. The quantum key distribution system exhibited a quantum bit error rate
of 1.4%, and an estimated net bit rate greater than 100,000 bits-per-second for
a 4.2 km transmission range. For a 10 km fiber range a quantum bit error rate
of 2.1%, and estimated net bit rate of greater than 7,000 bits-per-second was
achieved.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 10:12:10 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Gordon",
"Karen J.",
""
],
[
"Fernandez",
"Veronica",
""
],
[
"Townsend",
"Paul D.",
""
],
[
"Buller",
"Gerald S.",
""
]
] |
quant-ph/0605223
|
Vittorio Giovannetti
|
Vittorio Giovannetti
|
Entanglement and statistics in Hong-Ou-Mandel interferometry
|
7 pages, 3 figures; minor editorial changes and new references added
|
Laser Phys. 16 (2006) 1406-1410
|
10.1134/S1054660X06100033
| null |
quant-ph cond-mat.mes-hall hep-th
| null |
Hong-Ou-Mandel interferometry allows one to detect the presence of
entanglement in two-photon input states. The same result holds for
two-particles input states which obey to Fermionic statistics. In the latter
case however anti-bouncing introduces qualitative differences in the
interferometer response. This effect is analyzed in a Gedankenexperiment where
the particles entering the interferometer are assumed to belong to a
one-parameter family of quons which continuously interpolate between the
Bosonic and Fermionic statistics.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 10:34:23 GMT"
},
{
"version": "v2",
"created": "Sat, 1 Jul 2006 11:40:37 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Giovannetti",
"Vittorio",
""
]
] |
quant-ph/0605224
|
Dennis Kretschmann
|
Giacomo Mauro D'Ariano, Dennis Kretschmann, Dirk Schlingemann,
Reinhard F. Werner
|
Reexamination of Quantum Bit Commitment: the Possible and the Impossible
|
v1: 26 pages, 4 eps figures. v2: 31 pages, 5 eps figures; replaced
with published version; title changed to comply with puzzling Phys. Rev.
regulations; impossibility proof extended to protocols with infinitely many
rounds or a continuous communication tree; security proof of decoherence
monster protocol expanded; presentation clarified
|
Phys. Rev. A 76, 032328 (2007)
|
10.1103/PhysRevA.76.032328
| null |
quant-ph
| null |
Bit commitment protocols whose security is based on the laws of quantum
mechanics alone are generally held to be impossible. In this paper we give a
strengthened and explicit proof of this result. We extend its scope to a much
larger variety of protocols, which may have an arbitrary number of rounds, in
which both classical and quantum information is exchanged, and which may
include aborts and resets. Moreover, we do not consider the receiver to be
bound to a fixed "honest" strategy, so that "anonymous state protocols", which
were recently suggested as a possible way to beat the known no-go results are
also covered. We show that any concealing protocol allows the sender to find a
cheating strategy, which is universal in the sense that it works against any
strategy of the receiver. Moreover, if the concealing property holds only
approximately, the cheat goes undetected with a high probability, which we
explicitly estimate. The proof uses an explicit formalization of general two
party protocols, which is applicable to more general situations, and a new
estimate about the continuity of the Stinespring dilation of a general quantum
channel. The result also provides a natural characterization of protocols that
fall outside the standard setting of unlimited available technology, and thus
may allow secure bit commitment. We present a new such protocol whose security,
perhaps surprisingly, relies on decoherence in the receiver's lab.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 15:26:19 GMT"
},
{
"version": "v2",
"created": "Mon, 15 Oct 2007 14:34:02 GMT"
}
] | 2013-05-29T00:00:00 |
[
[
"D'Ariano",
"Giacomo Mauro",
""
],
[
"Kretschmann",
"Dennis",
""
],
[
"Schlingemann",
"Dirk",
""
],
[
"Werner",
"Reinhard F.",
""
]
] |
quant-ph/0605225
|
Yafei Yu
|
Yafei Yu, Yi Xu, Jin Liu
|
A quantum secret sharing scheme among three parties ultilizing
four-qubit Smolin bound entangled state
| null | null | null | null |
quant-ph
| null |
Four-qubit Smolin bound entangled state has a distinct feature: the state is
not distillable when every qubit is seperated from each other; but it makes two
separated qubit entangled if the other qubits group together. Here the feature
is applied to quantum secret sharing, a QSS protocol similar to Ekert 91
protocol of QKD is proposed. The security problem, disadvantage and advantageof
this protocol are disscused.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 14:49:49 GMT"
},
{
"version": "v2",
"created": "Sun, 28 May 2006 09:50:29 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Yu",
"Yafei",
""
],
[
"Xu",
"Yi",
""
],
[
"Liu",
"Jin",
""
]
] |
quant-ph/0605226
|
Feng Lu
|
Feng Lu and Dan C. Marinescu
|
Quantum Error Correction of Time-Correlated Errors
|
14 pages, 3 figures
| null | null | null |
quant-ph
| null |
The complexity of the error correction circuitry forces us to design quantum
error correction codes capable of correcting a single error per error
correction cycle. Yet, time-correlated error are common for physical
implementations of quantum systems; an error corrected during the previous
cycle may reoccur later due to physical processes specific for each physical
implementation of the qubits. In this paper we study quantum error correction
for a restricted class of time-correlated errors in a spin-boson model. The
algorithm we propose allows the correction of two errors per error correction
cycle, provided that one of them is time-correlated. The algorithm can be
applied to any stabilizer code when the two logical qubits $\mid 0_L>$ and
$\mid 1_L>$ are entangled states of $2^{n}$ basis states in
$\mathcal{H}_{2^n}$.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 18:50:10 GMT"
},
{
"version": "v2",
"created": "Tue, 30 Jan 2007 20:25:27 GMT"
},
{
"version": "v3",
"created": "Tue, 13 Feb 2007 00:35:37 GMT"
},
{
"version": "v4",
"created": "Fri, 6 Apr 2007 20:57:12 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Lu",
"Feng",
""
],
[
"Marinescu",
"Dan C.",
""
]
] |
quant-ph/0605227
|
Vinay Ambegaokar
|
Vinay Ambegaokar
|
Equilibration of a dissipative quantum oscillator
| null |
Ann. Phys. (Leipzig) 16, 319 (2007)
|
10.1002/andp.200610236
| null |
quant-ph cond-mat.stat-mech
| null |
An explicit demonstration is given of a harmonic oscillator in equilibrium
approaching the equilibrium of a corresponding interacting system by coupling
it to a thermal bath consisting of a continuum of harmonic oscillators.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 18:28:20 GMT"
}
] | 2007-06-27T00:00:00 |
[
[
"Ambegaokar",
"Vinay",
""
]
] |
quant-ph/0605228
|
Kovid Goyal
|
Kovid Goyal, Alex McCauley and Robert Raussendorf
|
Purification of large bicolorable graph states
|
12 pages, 5 figures, revtex; typos and clarifications added
|
Phys. Rev. A 74, 032318 (2006)
|
10.1103/PhysRevA.74.032318
| null |
quant-ph
| null |
We describe novel purification protocols for bicolorable graph states. The
protocols scale efficiently for large graph states. We introduce a method of
analysis that allows us to derive simple recursion relations characterizing
their behavior as well as analytical expressions for their thresholds and fixed
point behavior. We introduce two purification protocols with high threshold.
They can, for graph degree four, tolerate 1% (3%) gate error or 20% (30%) local
error.
|
[
{
"version": "v1",
"created": "Sun, 28 May 2006 17:24:30 GMT"
},
{
"version": "v2",
"created": "Sun, 17 Sep 2006 19:24:35 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Goyal",
"Kovid",
""
],
[
"McCauley",
"Alex",
""
],
[
"Raussendorf",
"Robert",
""
]
] |
quant-ph/0605229
|
Alberto Marino
|
Alberto M. Marino and C. R. Stroud, Jr
|
Deterministic Secure Communications using Two-Mode Squeezed States
|
10 pages, 4 figures
| null |
10.1103/PhysRevA.74.022315
| null |
quant-ph
| null |
We propose a scheme for quantum cryptography that uses the squeezing phase of
a two-mode squeezed state to transmit information securely between two parties.
The basic principle behind this scheme is the fact that each mode of the
squeezed field by itself does not contain any information regarding the
squeezing phase. The squeezing phase can only be obtained through a joint
measurement of the two modes. This, combined with the fact that it is possible
to perform remote squeezing measurements, makes it possible to implement a
secure quantum communication scheme in which a deterministic signal can be
transmitted directly between two parties while the encryption is done
automatically by the quantum correlations present in the two-mode squeezed
state.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 23:08:00 GMT"
}
] | 2012-08-27T00:00:00 |
[
[
"Marino",
"Alberto M.",
""
],
[
"Stroud,",
"C. R.",
"Jr"
]
] |
quant-ph/0605230
|
Alberto Marino
|
Alberto M. Marino, C. R. Stroud, Jr., Vincent Wong, Ryan S. Bennink,
and Robert W. Boyd
|
Bichromatic Local Oscillator for Detection of Two-Mode Squeezed States
of Light
|
11 pages, 3 figures
| null |
10.1364/JOSAB.24.000335
| null |
quant-ph
| null |
We present a new technique for the detection of two-mode squeezed states of
light that allows for a simple characterization of these quantum states. The
usual detection scheme, based on heterodyne measurements, requires the use of a
local oscillator with a frequency equal to the mean of the frequencies of the
two modes of the squeezed field. As a result, unless the two modes are close in
frequency, a high-frequency shot-noise-limited detection system is needed. We
propose the use of a bichromatic field as the local oscillator in the
heterodyne measurements. By the proper selection of the frequencies of the
bichromatic field, it is possible to arbitrarily select the frequency around
which the squeezing information is located, thus making it possible to use a
low-bandwidth detection system and to move away from any excess noise present
in the system.
|
[
{
"version": "v1",
"created": "Fri, 26 May 2006 23:26:49 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Marino",
"Alberto M.",
""
],
[
"Stroud,",
"C. R.",
"Jr."
],
[
"Wong",
"Vincent",
""
],
[
"Bennink",
"Ryan S.",
""
],
[
"Boyd",
"Robert W.",
""
]
] |
quant-ph/0605231
|
Giovanna Morigi Dr
|
David Vitali, Giovanna Morigi, J\"urgen Eschner
|
A single cold atom as efficient stationary source of EPR-entangled light
|
13 pages, 5 figures
|
Phys. Rev. A 74, 053814 (2006)
|
10.1103/PhysRevA.74.053814
| null |
quant-ph
| null |
The Stokes and anti-Stokes components of the spectrum of resonance
fluorescence of a single trapped atom, which originate from the mechanical
coupling between the scattered photons and the quantized motion of the atomic
center of mass, exhibit quantum correlations which are of two-mode-squeezing
type. We study and demonstrate the build-up of such correlations in a specific
setup, which is experimentally accessible, and where the atom acts as efficient
and continuous source of EPR-entangled, two-mode squeezed light.
|
[
{
"version": "v1",
"created": "Sat, 27 May 2006 13:34:01 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Jan 2007 13:34:24 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Vitali",
"David",
""
],
[
"Morigi",
"Giovanna",
""
],
[
"Eschner",
"Jürgen",
""
]
] |
quant-ph/0605232
|
Gustavo Lima
|
G. Lima, Leonardo Neves, Ivan F. Santos, J. G. Aguirre G\'omez, C.
Saavedra and S. P\'adua
|
Propagation of spatially entangled qudits through free space
|
5 Pages, 4 Figures, REVTeX4
|
Physical Review A 73, 032340 (2006)
|
10.1103/PhysRevA.73.032340
| null |
quant-ph
| null |
We show the propagation of entangled states of high-dimensional quantum
systems. The qudits states were generated using the transverse correlation of
the twin photons produced by spontaneous parametric down-conversion. Their
free-space distribution was performed at the laboratory scale and the
propagated states maintained a high-fidelity with their original form. The use
of entangled qudits allow an increase in the quantity of information that can
be transmitted and may also guarantee more privacy for communicating parties.
Therefore, studies about propagating entangled states of qudits are important
for the effort of building quantum communication networks.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 04:30:51 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Lima",
"G.",
""
],
[
"Neves",
"Leonardo",
""
],
[
"Santos",
"Ivan F.",
""
],
[
"Gómez",
"J. G. Aguirre",
""
],
[
"Saavedra",
"C.",
""
],
[
"Pádua",
"S.",
""
]
] |
quant-ph/0605233
|
Bhabani Prasad Mandal Dr.
|
Bhabani Prasad Mandal (Banaras Hindu University) and Saurabh Gupta
|
Pseudo-Hermitian Interactions in Dirac Theory: Examples
|
13 pages, Latex, No figs, Revised version to appear in MPLA
|
Mod. Phys. Lett. A 25, 1723 (2010)
|
10.1142/S0217732310032901
| null |
quant-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider a couple of examples to study the pseudo-Hermitian interaction in
relativistic quantum mechanics. Rasbha interaction, commonly used to study the
spin Hall effect, is considered with imaginary coupling. The corresponding
Dirac Hamiltonian is shown to be parity pseudo-Hermitian. In the other example
we consider parity pseudo-Hermitian scalar interaction with arbitrary parameter
in Dirac theory. In both the cases we show that the energy spectrum is real and
all the other features of non-relativistic pseudo-Hermitian formulation are
present. Using the spectral method the positive definite metric operator
($\eta$) has been calculated explicitly for both the models to ensure positive
definite norms for the state vectors.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 05:57:42 GMT"
},
{
"version": "v2",
"created": "Sat, 17 Feb 2007 05:55:47 GMT"
},
{
"version": "v3",
"created": "Thu, 18 Feb 2010 11:29:45 GMT"
}
] | 2015-09-30T00:00:00 |
[
[
"Mandal",
"Bhabani Prasad",
"",
"Banaras Hindu University"
],
[
"Gupta",
"Saurabh",
""
]
] |
quant-ph/0605234
|
Paul Barclay
|
Paul E. Barclay, Benjamin Lev, Kartik Srinivasan, Oskar Painter, Hideo
Mabuchi
|
Integration of fiber coupled high-Q silicon nitride microdisks with atom
chips
|
Published vesion. Minor changes
|
Appl. Phys. Lett. 89, 131108 (2006)
|
10.1063/1.2356892
| null |
quant-ph physics.optics
| null |
Micron scale silicon nitride (SiN_x) microdisk optical resonators are
demonstrated with Q = 3.6 x 10^6 and an effective mode volume of 15 (\lambda /
n)^3 at near visible wavelengths. A hydrofluoric acid wet etch provides
sensitive tuning of the microdisk resonances, and robust mounting of a fiber
taper provides efficient fiber optic coupling to the microdisks while allowing
unfettered optical access for laser cooling and trapping of atoms. Measurements
indicate that cesium adsorption on the SiN_x surfaces significantly red-detunes
the microdisk resonances. A technique for parallel integration of multiple (10)
microdisks with a single fiber taper is also demonstrated.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 07:00:43 GMT"
},
{
"version": "v2",
"created": "Tue, 30 May 2006 05:42:46 GMT"
},
{
"version": "v3",
"created": "Wed, 27 Sep 2006 20:35:06 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Barclay",
"Paul E.",
""
],
[
"Lev",
"Benjamin",
""
],
[
"Srinivasan",
"Kartik",
""
],
[
"Painter",
"Oskar",
""
],
[
"Mabuchi",
"Hideo",
""
]
] |
quant-ph/0605235
|
Bernhard G. Bodmann
|
Bernhard G. Bodmann, David W. Kribs and Vern I. Paulsen
|
Decoherence-Insensitive Quantum Communication by Optimal C^*-Encoding
|
20 pages, no figures, amsart
| null | null | null |
quant-ph
| null |
The central issue in this article is to transmit a quantum state in such a
way that after some decoherence occurs, most of the information can be restored
by a suitable decoding operation. For this purpose, we incorporate redundancy
by mapping a given initial quantum state to a messenger state on a
larger-dimensional Hilbert space via a $C^*$-algebra embedding. Our noise model
for the transmission is a phase damping channel which admits a noiseless or
decoherence-free subspace or subsystem. More precisely, the transmission
channel is obtained from convex combinations of a set of lowest rank yes/no
measurements that leave a component of the messenger state unchanged. The
objective of our encoding is to distribute quantum information optimally across
the noise-susceptible component of the transmission when the noiseless
component is not large enough to contain all the quantum information to be
transmitted. We derive simple geometric conditions for optimal encoding and
construct examples.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 18:34:08 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Bodmann",
"Bernhard G.",
""
],
[
"Kribs",
"David W.",
""
],
[
"Paulsen",
"Vern I.",
""
]
] |
quant-ph/0605236
|
Adnan Tegmen
|
T. Hakioglu, A. Tegmen, B. Demircioglu
|
$\hbar$-independent Universality of the Quantum-Classical Canonical
Transformations
|
13 pages, no figures
|
Phys. Lett. A 360 (2007) 501-506
|
10.1016/j.physleta.2006.08.060
| null |
quant-ph
| null |
A theory of non-unitary-invertible as well as unitary canonical
transformations is formulated in the context of Weyl's phase space
representations. That all quantum canonical transformations without an explicit
$\hbar$ dependence are also classical mechanical and vice versa is demonstrated
in the phase space. Contrary to some earlier results, it is also shown that the
quantum generators and their classical counterparts are identical and
$\hbar$-independent. The latter is a powerful result bringing the theory of
classical canonical transformations and the $\hbar$-independent quantum ones on
an equal footing.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 07:58:01 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Hakioglu",
"T.",
""
],
[
"Tegmen",
"A.",
""
],
[
"Demircioglu",
"B.",
""
]
] |
quant-ph/0605237
|
Vivi Petersen
|
Vivi Petersen and Klaus Molmer
|
Estimation of fluctuating magnetic fields by an atomic magnetometer
|
8 pages, 6 figures
| null |
10.1103/PhysRevA.74.043802
| null |
quant-ph
| null |
We present a theoretical analysis of the ability of atomic magnetometers to
estimate a fluctuating magnetic field. Our analysis makes use of a Gaussian
state description of the atoms and the probing field, and it presents the
estimator of the field and a measure of its uncertainty which coincides in the
appropriate limit with the achievements for a static field. We show by
simulations that the estimator for the current value of the field
systematically lags behind the actual value of the field, and we suggest a more
complete theory, where measurement results at any time are used to update and
improve both the estimate of the current value and the estimate of past values
of the B-field.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 08:25:32 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Petersen",
"Vivi",
""
],
[
"Molmer",
"Klaus",
""
]
] |
quant-ph/0605238
|
Gabriel Hetet
|
G. Hetet, A. Peng, M. T. Johnsson, M. T. L. Hsu, O. Gloeckl, P. K.
Lam, H .A. Bachor, and J. J. Hope
|
Erratum : Squeezing and entanglement delay using slow light
|
1 page, no figure
| null |
10.1103/PhysRevA.74.059902
| null |
quant-ph
| null |
An inconsistency was found in the equations used to calculate the variance of
the quadrature fluctuations of a field propagating through a medium
demonstrating electromagnetically induced transparency (EIT). The decoherence
term used in our original paper introduces inconsistency under weak probe
approximation. In this erratum we give the Bloch equations with the correct
dephasing terms. The conclusions of the original paper remain the same. Both
entanglement and squeezing can be delayed and preserved using EIT without
adding noise when the decoherence rate is small.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 09:25:53 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Hetet",
"G.",
""
],
[
"Peng",
"A.",
""
],
[
"Johnsson",
"M. T.",
""
],
[
"Hsu",
"M. T. L.",
""
],
[
"Gloeckl",
"O.",
""
],
[
"Lam",
"P. K.",
""
],
[
"Bachor",
"H . A.",
""
],
[
"Hope",
"J. J.",
""
]
] |
quant-ph/0605239
|
Michel R. P. Planat
|
Michel R. P. Planat (FEMTO-ST), Metod Saniga (FEMTO-ST, Astrinstsav),
Maurice R. Kibler (IPNL)
|
Quantum Entanglement and Projective Ring Geometry
|
13 pages, 6 figures Fig. 3 improved, typos corrected; Version 4:
Final Version Published in SIGMA (Symmetry, Integrability and Geometry:
Methods and Applications) at http://www.emis.de/journals/SIGMA/
|
Symmetry, Integrability and Geometry: Methods and Applications
(SIGMA) 2 (2006) Paper 066, 14 pages
| null | null |
quant-ph math-ph math.MP
| null |
The paper explores the basic geometrical properties of the observables
characterizing two-qubit systems by employing a novel projective ring geometric
approach. After introducing the basic facts about quantum complementarity and
maximal quantum entanglement in such systems, we demonstrate that the
15$\times$15 multiplication table of the associated four-dimensional matrices
exhibits a so-far-unnoticed geometrical structure that can be regarded as three
pencils of lines in the projective plane of order two. In one of the pencils,
which we call the kernel, the observables on two lines share a base of Bell
states. In the complement of the kernel, the eight vertices/observables are
joined by twelve lines which form the edges of a cube. A substantial part of
the paper is devoted to showing that the nature of this geometry has much to do
with the structure of the projective lines defined over the rings that are the
direct product of $n$ copies of the Galois field GF(2), with $n$ = 2, 3 and 4.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 12:28:28 GMT"
},
{
"version": "v2",
"created": "Mon, 12 Jun 2006 13:04:42 GMT"
},
{
"version": "v3",
"created": "Tue, 15 Aug 2006 19:26:24 GMT"
},
{
"version": "v4",
"created": "Fri, 18 Aug 2006 13:10:10 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Planat",
"Michel R. P.",
"",
"FEMTO-ST"
],
[
"Saniga",
"Metod",
"",
"FEMTO-ST, Astrinstsav"
],
[
"Kibler",
"Maurice R.",
"",
"IPNL"
]
] |
quant-ph/0605240
|
XiaoHu Zheng
|
Xiao-Hu Zheng, Ping Dong, Zheng-Yuan Xue, Zhuo-Liang Cao
|
Generation of cluster states with Josephson charge qubits
|
3 figures, 4 pages
|
Phys. Lett. A 365, 156 (2007) .
|
10.1016/j.physleta.2006.12.066
| null |
quant-ph
| null |
A scheme for the generation of the cluster states based on the Josephson
charge qubit is proposed. The two-qubit generating case is first introduced,
and then generalized to multi-qubit case. The scheme is simple and easily
manipulated, because any two charge qubits can be selectively and effectively
coupled by a common inductance. More manipulations can be realized before
decoherence sets in. All the devices in the scheme are well within the current
technology.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 12:45:48 GMT"
}
] | 2008-04-01T00:00:00 |
[
[
"Zheng",
"Xiao-Hu",
""
],
[
"Dong",
"Ping",
""
],
[
"Xue",
"Zheng-Yuan",
""
],
[
"Cao",
"Zhuo-Liang",
""
]
] |
quant-ph/0605241
|
Olli-Pentti Saira
|
Olli-Pentti Saira, Ville Bergholm, Teemu Ojanen, Mikko Mottonen
|
Equivalent qubit dynamics under classical and quantum noise
|
5 pages, 2 figures; converted to PRA format, added Fig. 2, corrected
typos
|
Phys. Rev. A 75, 012308 (2007)
|
10.1103/PhysRevA.75.012308
| null |
quant-ph
| null |
We study the dynamics of quantum systems under classical and quantum noise,
focusing on decoherence in qubit systems. Classical noise is described by a
random process leading to a stochastic temporal evolution of a closed quantum
system, whereas quantum noise originates from the coupling of the microscopic
quantum system to its macroscopic environment. We derive deterministic master
equations describing the average evolution of the quantum system under
classical continuous-time Markovian noise and two sets of master equations
under quantum noise. Strikingly, these three equations of motion are shown to
be equivalent in the case of classical random telegraph noise and proper
quantum environments. Hence fully quantum-mechanical models within the Born
approximation can be mapped to a quantum system under classical noise.
Furthermore, we apply the derived equations together with pulse optimization
techniques to achieve high-fidelity one-qubit operations under random telegraph
noise, and hence fight decoherence in these systems of great practical
interest.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 12:59:19 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Feb 2007 08:01:30 GMT"
}
] | 2010-10-25T00:00:00 |
[
[
"Saira",
"Olli-Pentti",
""
],
[
"Bergholm",
"Ville",
""
],
[
"Ojanen",
"Teemu",
""
],
[
"Mottonen",
"Mikko",
""
]
] |
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