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2025-04-04 00:00:00
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/0604058
|
A. M. Fedotov
|
A.M. Fedotov, Yu.E. Lozovik, N.B. Narozhny, and A.N. Petrosyan
|
Dynamical Casimir Effect in a one-dimensional uniformly contracting
cavity
|
13 pages, 4 figures
|
Phys. Rev. A 74, 013806 (2006)
|
10.1103/PhysRevA.74.013806
| null |
quant-ph
| null |
We consider particle creation (the Dynamical Casimir effect) in a uniformly
contracting ideal one-dimensional cavity non-perturbatively. The exact
expression for the energy spectrum of created particles is obtained and its
dependence on parameters of the problem is discussed. Unexpectedly, the number
of created particles depends on the duration of the cavity contracting
non-monotonously. This is explained by quantum interference of the events of
particle creation which are taking place only at the moments of acceleration
and deceleration of a boundary, while stable particle states exist (and thus no
particles are created) at the time of contracting.
|
[
{
"version": "v1",
"created": "Sun, 9 Apr 2006 16:36:30 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Fedotov",
"A. M.",
""
],
[
"Lozovik",
"Yu. E.",
""
],
[
"Narozhny",
"N. B.",
""
],
[
"Petrosyan",
"A. N.",
""
]
] |
quant-ph/0604059
|
Bin Shang
|
Bin Shang
|
Query complexity for searching multiple marked states from an unsorted
database
|
4 pages,4 figures,twocolumn
| null |
10.1088/0253-6102/48/2/013
| null |
quant-ph
| null |
An important and usual problem is to search all states we want from a
database with a large number of states. In such, recall is vital. Grover's
original quantum search algorithm has been generalized to the case of multiple
solutions, but no one has calculated the query complexity in this case. We will
use a generalized algorithm with higher precision to solve such a search
problem that we should find all marked states and show that the practical query
complexity increases with the number of marked states. In the end we will
introduce an algorithm for the problem on a ``duality computer'' and show its
advantage over other algorithms.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 11:39:37 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Shang",
"Bin",
""
]
] |
quant-ph/0604060
|
Fu-Guo Deng
|
Fu-Guo Deng, Xi-Han Li, Pan Chen, Chun-Yan Li, and Hong-Yu Zhou
|
Fake-signal-and-cheating attack on quantum secret sharing
|
5 page, no figure
| null | null | null |
quant-ph
| null |
We present a fake-signal-and-cheating attack strategy for the dishonest agent
in quantum secret sharing (QSS) to steal the information of the other agents'
fully and freely. It is found that almost all the QSS protocols existing, such
as the two famous QSS protocols, the Hillery-Bu$\check{z}$ek-Berthiaume [Phys.
Rev. A \textbf{59}, 1829 (1999)] and the Karlsson-Koashi-Imoto [Phys. Rev. A
\textbf{59}, 162 (1999)], can be eavesdropped freely if the process for the
eavesdropping check is accomplished with the cooperation of the dishonest
agent. He can sends a fake signal to the other agents after intercepting the
original photons and storing them. His action can be hidden with entanglement
swapping and cheating when the photons are chosen as the samples for checking
eavesdropping. Finally, we present a possible improvement of these QSS
protocols' security with decoy photons.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 11:10:57 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Deng",
"Fu-Guo",
""
],
[
"Li",
"Xi-Han",
""
],
[
"Chen",
"Pan",
""
],
[
"Li",
"Chun-Yan",
""
],
[
"Zhou",
"Hong-Yu",
""
]
] |
quant-ph/0604061
|
Harumichi Nishimura
|
Masahito Hayashi, Kazuo Iwama, Harumichi Nishimura, Rudy Raymond,
Shigeru Yamashita
|
(4,1)-Quantum Random Access Coding Does Not Exist
|
8pages, 3figures
|
New J. Phys 8 (2006) 129
|
10.1088/1367-2630/8/8/129
| null |
quant-ph
| null |
An (n,1,p)-Quantum Random Access (QRA) coding, introduced by Ambainis, Nayak,
Ta-shma and Vazirani in ACM Symp. on Theory of Computing 1999, is the following
communication system: The sender which has n-bit information encodes his/her
information into one qubit, which is sent to the receiver. The receiver can
recover any one bit of the original n bits correctly with probability at least
p, through a certain decoding process based on positive operator-valued
measures. Actually, Ambainis et al. shows the existence of a (2,1,0.85)-QRA
coding and also proves the impossibility of its classical counterpart. Chuang
immediately extends it to a (3,1,0.79)-QRA coding and whether or not a
(4,1,p)-QRA coding such that p > 1/2 exists has been open since then. This
paper gives a negative answer to this open question.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 03:23:45 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Hayashi",
"Masahito",
""
],
[
"Iwama",
"Kazuo",
""
],
[
"Nishimura",
"Harumichi",
""
],
[
"Raymond",
"Rudy",
""
],
[
"Yamashita",
"Shigeru",
""
]
] |
quant-ph/0604062
|
Dafa Li
|
D. Li, X.Li, H. Huang, X. Li
|
Fixed-point Quantum Search for Different Phase Shifts
|
8 pages
|
Phys. Lett. A 362, 260-264 (2007)
|
10.1016/j.physleta.2006.10.030
| null |
quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Grover recently presented the fixed-point search algorithm. In this letter,
we study the fixed-point search algorithm obtained by replacing equal phase
shifts of $\pi /3$ by different phase shifts.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 03:40:11 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Jul 2006 08:59:19 GMT"
},
{
"version": "v3",
"created": "Fri, 18 Aug 2006 08:32:14 GMT"
},
{
"version": "v4",
"created": "Mon, 21 Dec 2009 08:39:15 GMT"
}
] | 2012-05-08T00:00:00 |
[
[
"Li",
"D.",
""
],
[
"Li",
"X.",
""
],
[
"Huang",
"H.",
""
],
[
"Li",
"X.",
""
]
] |
quant-ph/0604063
|
S. Javad Akhtarshenas
|
S. Javad Akhtarshenas
|
Canonical Coset Parameterization and the Bures Metric of the Three-level
Quantum Systems
|
12 pages, 1 figure, typos fixed, references added
|
J. Math. Phys., Vol. 48, 012102 (2007)
| null | null |
quant-ph
| null |
An explicit parameterization for the state space of an $n$-level density
matrix is given. The parameterization is based on the canonical coset
decomposition of unitary matrices. We also compute, explicitly, the Bures
metric tensor over the state space of two- and three-level quantum systems.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 05:45:08 GMT"
},
{
"version": "v2",
"created": "Sun, 14 Jan 2007 16:20:48 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Akhtarshenas",
"S. Javad",
""
]
] |
quant-ph/0604064
|
Carlo Rovelli
|
Matteo Smerlak, Carlo Rovelli
|
Relational EPR
|
Revised, published version
|
Found.Phys.37:427-445,2007
|
10.1007/s10701-007-9105-0
| null |
quant-ph gr-qc physics.hist-ph
| null |
We study the EPR-type correlations from the perspective of the relational
interpretation of quantum mechanics. We argue that these correlations do not
entail any form of 'non-locality', when viewed in the context of this
interpretation. The abandonment of strict Einstein realism implied by the
relational stance permits to reconcile quantum mechanics, completeness,
(operationally defined) separability, and locality.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 08:47:06 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Feb 2007 23:18:19 GMT"
},
{
"version": "v3",
"created": "Sun, 4 Mar 2007 16:20:04 GMT"
}
] | 2013-05-07T00:00:00 |
[
[
"Smerlak",
"Matteo",
""
],
[
"Rovelli",
"Carlo",
""
]
] |
quant-ph/0604065
|
Ralf Schutzhold
|
Ralf Sch\"utzhold, Gernot Schaller, Dietrich Habs
|
Signatures of the Unruh effect from electrons accelerated by
ultra-strong laser fields
|
4 pages, 1 figure
|
Phys.Rev.Lett. 97 (2006) 121302; Erratum-ibid. 97 (2006) 139902
|
10.1103/PhysRevLett.97.121302
| null |
quant-ph
| null |
We calculate the radiation resulting from the Unruh effect for strongly
accelerated electrons and show that the photons are created in pairs whose
polarizations are maximally entangled. Apart from the photon statistics, this
quantum radiation can further be discriminated from the classical (Larmor)
radiation via the different spectral and angular distributions. The signatures
of the Unruh effect become significant if the external electromagnetic field
accelerating the electrons is not too far below the Schwinger limit and might
be observable with future facilities. Finally, the corrections due to the
birefringent nature of the QED vacuum at such ultra-high fields are discussed.
PACS: 04.62.+v, 12.20.Fv, 41.60.-m, 42.25.Lc.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 10:04:19 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Schützhold",
"Ralf",
""
],
[
"Schaller",
"Gernot",
""
],
[
"Habs",
"Dietrich",
""
]
] |
quant-ph/0604066
|
Farhan Saif
|
Farhan Saif
|
Classical and Quantum Chaos in Atom Optics
|
105 pages, 14 figures
|
Physics Reports 419, 207 (2005); Physics Reports 425, 369 (2006)
|
10.1016/j.physrep.2005.12.004
| null |
quant-ph nlin.CD
| null |
The interaction of an atom with an electromagnetic field is discussed in the
presence of a time periodic external modulating force. It is explained that a
control on atom by electromagnetic fields helps to design the quantum analog of
classical optical systems. In these atom optical systems chaos may appear at
the onset of external fields. The classical and quantum chaotic dynamics is
discussed, in particular in an atom optics Fermi accelerator. It is found that
the quantum dynamics exhibits dynamical localization and quantum recurrences.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 12:06:54 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Saif",
"Farhan",
""
]
] |
quant-ph/0604067
|
Dario Tamascelli
|
Diego de Falco and Dario Tamascelli
|
Speed and entropy of an interacting continuous time quantum walk
|
25 pages, 14 figures
|
J. Phys. A: Math. Gen. 39 (2006) 5873-5895
|
10.1088/0305-4470/39/20/016
| null |
quant-ph
| null |
We present some dynamic and entropic considerations about the evolution of a
continuous time quantum walk implementing the clock of an autonomous machine.
On a simple model, we study in quite explicit terms the Lindblad evolution of
the clocked subsystem, relating the evolution of its entropy to the spreading
of the wave packet of the clock. We explore possible ways of reducing the
generation of entropy in the clocked subsystem, as it amounts to a deficit in
the probability of finding the target state of the computation. We are thus
lead to examine the benefits of abandoning some classical prejudice about how a
clocking mechanism should operate.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 14:05:36 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Apr 2006 08:21:20 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"de Falco",
"Diego",
""
],
[
"Tamascelli",
"Dario",
""
]
] |
quant-ph/0604068
|
Haba Zbigniew
|
Z. Haba
|
Bounds on the heat kernel of the Schroedinger operator in a random
electromagnetic field
|
some technical improvements, new references, to appear in
Journ.Phys.A
| null |
10.1088/0305-4470/39/31/019
| null |
quant-ph math-ph math.MP
| null |
We obtain lower and upper bounds on the heat kernel and Green functions of
the Schroedinger operator in a random Gaussian magnetic field and a fixed
scalar potential. We apply stochastic Feynman-Kac representation, diamagnetic
upper bounds and the Jensen inequality for the lower bound. We show that if the
covariance of the electromagnetic (vector) potential is increasing at large
distances then the lower bound is decreasing exponentially fast for large
distances and a large time.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 14:29:34 GMT"
},
{
"version": "v2",
"created": "Mon, 19 Jun 2006 12:01:59 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Haba",
"Z.",
""
]
] |
quant-ph/0604069
|
Elena Rufeil
|
E. Rufeil Fiori and H. M. Pastawski
|
Survival probability of surface excitations in a 2d lattice:
non-Markovian effects and Survival Collapse
|
4 pages, 3 figures. Braz. Journ. of Phys., in press. Braz. Journ. of
Phys., in press. Braz. Journ. of Phys., in press. Braz. Journ. of Phys., in
press. Braz. Journ. of Phys., in press. Braz. Journ. of Phys., in press.
Braz. Journ. of Phys., in press
| null |
10.1590/S0103-97332006000600012
| null |
quant-ph
| null |
The evolution of a surface excitation in a two dimentional model is analyzed.
I) It starts quadratically up to a spreading time t_{S}. II) It follows an
exponential behavior governed by a self-consistent Fermi Golden Rule. III) At
longer times, the exponential is overrun by an inverse power law describing
return processes governed by quantum diffusion. At this last transition time
t_{R} a survival collapse becomes possible, bringing the survival probability
down by several orders of magnitude. We identify this strongly destructive
interference as an antiresonance in the time domain.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 18:37:22 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Fiori",
"E. Rufeil",
""
],
[
"Pastawski",
"H. M.",
""
]
] |
quant-ph/0604070
|
Tzvetan Metodi
|
Darshan D. Thaker (1), Tzvetan S. Metodi (1), Andrew W. Cross (3),
Isaac L. Chuang (3), Frederic T. Chong (2) ((1) University of California at
Davis, (2) University of California at Santa Barbara, (3) Massachusetts
Institute of Technology)
|
Quantum Memory Hierarchies: Efficient Designs to Match Available
Parallelism in Quantum Computing
|
12 pages, 8 figures, To appear in the International Symposium on
Computer Architecture (ISCA-33), Boston, MA, 2006
| null | null | null |
quant-ph
| null |
The assumption of maximum parallelism support for the successful realization
of scalable quantum computers has led to homogeneous, ``sea-of-qubits''
architectures. The resulting architectures overcome the primary challenges of
reliability and scalability at the cost of physically unacceptable system area.
We find that by exploiting the natural serialization at both the application
and the physical microarchitecture level of a quantum computer, we can reduce
the area requirement while improving performance. In particular we present a
scalable quantum architecture design that employs specialization of the system
into memory and computational regions, each individually optimized to match
hardware support to the available parallelism. Through careful application and
system analysis, we find that our new architecture can yield up to a factor of
thirteen savings in area due to specialization. In addition, by providing a
memory hierarchy design for quantum computers, we can increase time performance
by a factor of eight. This result brings us closer to the realization of a
quantum processor that can solve meaningful problems.
|
[
{
"version": "v1",
"created": "Mon, 10 Apr 2006 20:36:25 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Thaker",
"Darshan D.",
""
],
[
"Metodi",
"Tzvetan S.",
""
],
[
"Cross",
"Andrew W.",
""
],
[
"Chuang",
"Isaac L.",
""
],
[
"Chong",
"Frederic T.",
""
]
] |
quant-ph/0604071
|
Ruixue Xu
|
Ping Han, Rui-Xue Xu, Baiqing Li, Jian Xu, Ping Cui, Yan Mo, YiJing
Yan
|
Kinetics and thermodynamics of electron transfer in Debye solvents: An
analytical and nonperturbative reduced density matrix theory
|
8 pages, 5 figures. J. Phys. Chem. B, accepted
| null | null | null |
quant-ph
| null |
A nonperturbative electron transfer rate theory is developed based on the
reduced density matrix dynamics, which can be evaluated readily for the Debye
solvent model without further approximation. Not only does it recover for
reaction rates the celebrated Marcus' inversion and Kramers' turnover
behaviors, the present theory also predicts for reaction thermodynamics, such
as equilibrium Gibbs free-energy and entropy, some interesting
solvent-dependent features that are calling for experimental verification.
Moreover, a continued fraction Green's function formalism is also constructed,
which can be used together with Dyson equation technique, for efficient
evaluation of nonperturbative reduced density matrix dynamics.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 04:42:56 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Han",
"Ping",
""
],
[
"Xu",
"Rui-Xue",
""
],
[
"Li",
"Baiqing",
""
],
[
"Xu",
"Jian",
""
],
[
"Cui",
"Ping",
""
],
[
"Mo",
"Yan",
""
],
[
"Yan",
"YiJing",
""
]
] |
quant-ph/0604072
|
Gilles Brassard
|
Gilles Brassard
|
Brief History of Quantum Cryptography: A Personal Perspective
|
14 pages, no figures
|
Proceedings of IEEE Information Theory Workshop on Theory and
Practice in Information Theoretic Security, Awaji Island, Japan, pp. 19-23,
October 2005
|
10.1109/ITWTPI.2005.1543949
| null |
quant-ph
| null |
Quantum cryptography is the only approach to privacy ever proposed that
allows two parties (who do not share a long secret key ahead of time) to
communicate with provably perfect secrecy under the nose of an eavesdropper
endowed with unlimited computational power and whose technology is limited by
nothing but the fundamental laws of nature. This essay provides a personal
historical perspective on the field. For the sake of liveliness, the style is
purposely that of a spontaneous after-dinner speech.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 14:21:25 GMT"
}
] | 2016-11-18T00:00:00 |
[
[
"Brassard",
"Gilles",
""
]
] |
quant-ph/0604073
|
Ramazan Sever
|
Sameer M. Ikhdair and Ramazan Sever
|
Bound energy for the exponential-cosine-screened Coulomb potential
|
18 pages
|
J. Math. Chem. 41, 329(2007)
| null | null |
quant-ph
| null |
An alternative approximation scheme has been used in solving the Schrodinger
equation for the exponential-cosine-screened Coulomb potential. The bound state
energ\i es for various eigenstates and the corresponding wave functions are
obtained analytically up to the second perturbation term.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 08:04:39 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Ikhdair",
"Sameer M.",
""
],
[
"Sever",
"Ramazan",
""
]
] |
quant-ph/0604074
|
Klaus Hornberger
|
Klaus Hornberger
|
Thermal limitation of far-field matter-wave interference
|
8 pages, 2 figures; published version
|
Phys. Rev. A 73, 052102 (2006)
|
10.1103/PhysRevA.73.052102
| null |
quant-ph
| null |
We assess the effect of the heat radiation emitted by mesoscopic particles on
their ability to show interference in a double slit arrangement. The analysis
is based on a stationary, phase-space based description of matter wave
interference in the presence of momentum-exchange mediated decoherence.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 09:17:16 GMT"
},
{
"version": "v2",
"created": "Wed, 10 May 2006 16:50:57 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Hornberger",
"Klaus",
""
]
] |
quant-ph/0604075
|
Mikhail Krivoruchenko
|
M. I. Krivoruchenko (Moscow, ITEP & Tubingen U.) and Amand Faessler
(Tubingen U.)
|
Weyl's symbols of Heisenberg operators of canonical coordinates and
momenta as quantum characteristics
|
27 pages REVTeX, 6 EPS Figures. New references added. Accepted for
publication to JMP
|
J.Math.Phys.48:052107,2007
|
10.1063/1.2735816
| null |
quant-ph cond-mat.stat-mech hep-th math-ph math.AP math.CA math.DS math.MP
| null |
The knowledge of quantum phase flow induced under the Weyl's association rule
by the evolution of Heisenberg operators of canonical coordinates and momenta
allows to find the evolution of symbols of generic Heisenberg operators. The
quantum phase flow curves obey the quantum Hamilton's equations and play the
role of characteristics. At any fixed level of accuracy of semiclassical
expansion, quantum characteristics can be constructed by solving a coupled
system of first-order ordinary differential equations for quantum trajectories
and generalized Jacobi fields. Classical and quantum constraint systems are
discussed. The phase-space analytic geometry based on the star-product
operation can hardly be visualized. The statement "quantum trajectory belongs
to a constraint submanifold" can be changed e.g. to the opposite by a unitary
transformation. Some of relations among quantum objects in phase space are,
however, left invariant by unitary transformations and support partly geometric
relations of belonging and intersection. Quantum phase flow satisfies the
star-composition law and preserves hamiltonian and constraint star-functions.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 11:26:56 GMT"
},
{
"version": "v2",
"created": "Thu, 30 Nov 2006 11:07:56 GMT"
},
{
"version": "v3",
"created": "Sat, 12 May 2007 10:58:07 GMT"
}
] | 2016-09-08T00:00:00 |
[
[
"Krivoruchenko",
"M. I.",
"",
"Moscow, ITEP & Tubingen U."
],
[
"Faessler",
"Amand",
"",
"Tubingen U."
]
] |
quant-ph/0604076
|
Daniela Dragoman
|
Daniela Dragoman
|
Evolution Law of Quantum Observables from Classical Hamiltonian in
Non-Commutative Phase Space
|
10 pages, no figures
| null | null | null |
quant-ph
| null |
The evolution equations of quantum observables are derived from the classical
Hamiltonian equations of motion with the only additional assumption that the
phase space is non-commutative. The demonstration of the quantum evolution laws
is quite general; it does not rely on any assumption on the operator nature of
x and p and is independent of the quantum mechanical formalism.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 10:49:55 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Dragoman",
"Daniela",
""
]
] |
quant-ph/0604077
|
Zhaohui Wei
|
Zhaohui Wei and Mingsheng Ying
|
Quantum adiabatic evolutions that can't be used to design efficient
algorithms
|
4 pages, 1 figure
| null | null | null |
quant-ph
| null |
Quantum adiabatic computation is a novel paradigm for the design of quantum
algorithms, which is usually used to find the minimum of a classical function.
In this paper, we show that if the initial hamiltonian of a quantum adiabatic
evolution with a interpolation path is too simple, the minimal gap between the
ground state and the first excited state of this quantum adiabatic evolution is
an inverse exponential distance. Thus quantum adiabatic evolutions of this kind
can't be used to design efficient quantum algorithms. Similarly, we show that a
quantum adiabatic evolution with a simple final hamiltonian also has a long
running time, which suggests that some functions can't be minimized efficiently
by any quantum adiabatic evolution with a interpolation path.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 13:30:27 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Apr 2006 15:55:26 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Wei",
"Zhaohui",
""
],
[
"Ying",
"Mingsheng",
""
]
] |
quant-ph/0604078
|
Ramazan Sever
|
Sameer M. Ikhdair and Ramazan Sever
|
Bound states of a more general exponential screened Coulomb potential
|
14 pages
|
J. Math. Chem. 41, 343(2007)
| null | null |
quant-ph
| null |
An alternative approximation scheme has been used in solving the Schrodinger
equation to the more general case of exponential screened Coulomb potential,
V(r)=-(a/r)\[1+(1+br)e^{-2br}]. The bound state energies of the 1s, $2s, and
3s-states, together with the ground state wave function are obtained
analytically upto the second perturbation term.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 13:35:03 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Ikhdair",
"Sameer M.",
""
],
[
"Sever",
"Ramazan",
""
]
] |
quant-ph/0604079
|
Simon Kochen
|
John Conway, Simon Kochen
|
The Free Will Theorem
|
31 pages, 6figures
| null |
10.1007/s10701-006-9068-6
| null |
quant-ph
| null |
On the basis of three physical axioms, we prove that if the choice of a
particular type of spin 1 experiment is not a function of the information
accessible to the experimenters, then its outcome is equally not a function of
the information accessible to the particles. We show that this result is
robust, and deduce that neither hidden variable theories nor mechanisms of the
GRW type for wave function collapse can be made relativistic. We also establish
the consistency of our axioms and discuss the philosophical implications.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 14:06:42 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Conway",
"John",
""
],
[
"Kochen",
"Simon",
""
]
] |
quant-ph/0604080
|
Doyeol (David) Ahn
|
Doyeol Ahn
|
Effects of Hawking radiation and Wigner rotation on fermion entanglement
|
version 3
| null | null | null |
quant-ph
| null |
In this work, we report that the Hawking radiation effect on fermions is
fundamentally different from the case of scalar particles. Intrinsic properties
of fermions (exclusion principle and spin) affect strongly the interaction of
fermions with both Hawking radiation and metric of the spacetime. In particular
we have found the following: first, while the fermion vacuum state seen by the
Rindler observer is an entangled state in which the right and left Rindler
wedge states appear in correlated pairs as in the case of the scalar particles,
the entanglement disappears in the excited state due to the exclusion
principle; second, the spin of the fermion experiences the Winger rotation
under a uniform acceleration; and third, the quantum information of fermions
encoded in spin (entangled state is composed of different spin states but with
the same mode function) is dissipated not by the Hawking radiation but by the
Wigner rotation as the pair approaches the event horizon.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 16:57:17 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Sep 2006 04:27:23 GMT"
},
{
"version": "v3",
"created": "Wed, 27 Sep 2006 04:19:55 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Ahn",
"Doyeol",
""
]
] |
quant-ph/0604081
|
Stephan Goetzinger
|
S. Gotzinger, L. de S. Menezes, A. Mazzei, O. Benson, S. Kuhn, V.
Sandoghdar
|
Controlled photon transfer between two individual nanoemitters via
shared high-Q modes of a microsphere resonator
|
accepted for publication in Nano Letters
| null |
10.1021/nl060306p
| null |
quant-ph
| null |
We realize controlled cavity-mediated photon transfer between two single
nanoparticles over a distance of several tens of micrometers. First, we show
how a single nanoscopic emitter attached to a near-field probe can be coupled
to high-Q whispering-gallery modes of a silica microsphere at will. Then we
demonstrate transfer of energy between this and a second nanoparticle deposited
on the sphere surface. We estimate the photon transfer efficiency to be about
six orders of magnitude higher than that via free space propagation at
comparable separations.
|
[
{
"version": "v1",
"created": "Tue, 11 Apr 2006 23:37:54 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Gotzinger",
"S.",
""
],
[
"Menezes",
"L. de S.",
""
],
[
"Mazzei",
"A.",
""
],
[
"Benson",
"O.",
""
],
[
"Kuhn",
"S.",
""
],
[
"Sandoghdar",
"V.",
""
]
] |
quant-ph/0604082
|
Angel S. Sanz
|
A. S. Sanz, H. Han, and P. Brumer
|
Aspects of quantum coherence in the optical Bloch equations
|
18 pages, 6 figures; to appear in J Chem Phys
|
J. Chem. Phys. 124, 214106 (2006)
|
10.1063/1.2200703
| null |
quant-ph
| null |
Aspects of coherence and decoherence are analyzed within the optical Bloch
equations. By rewriting the analytic solution in an alternate form, we are able
to emphasize a number of unusual features: (a) despite the Markovian nature of
the bath, coherence at long times can be retained; (b) the long-time asymptotic
degree of coherence in the system is intertwined with the asymptotic difference
in level populations; (c) the traditional population-relaxation and decoherence
times, $T_1$ and $T_2$, lose their meaning when the system is in the presence
of an external field, and are replaced by more general overall timescales; (d)
increasing the field strength, quantified by the Rabi frequency, $\Omega$,
increases the rate of decoherence rather than reducing it, as one might expect;
and (e) maximum asymptotic coherence is reached when the system parameters
satisfy $\Omega^2 = 1/(T_1 T_2)$.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 08:08:21 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Sanz",
"A. S.",
""
],
[
"Han",
"H.",
""
],
[
"Brumer",
"P.",
""
]
] |
quant-ph/0604083
|
Zeqian Chen
|
Zeqian Chen
|
Wave equations for determining energy-level gaps of quantum systems
|
3 pages
| null | null | null |
quant-ph
| null |
An differential equation for wave functions is proposed, which is equivalent
to Schr\"{o}dinger's wave equation and can be used to determine energy-level
gaps of quantum systems. Contrary to Schr\"{o}dinger's wave equation, this
equation is on `bipartite' wave functions. It is shown that those `bipartite'
wave functions satisfy all the basic properties of Schr\"{o}dinger's wave
functions. Further, it is argued that `bipartite' wave functions can present a
mathematical expression of wave-particle duality. This provides an alternative
approach to the mathematical formalism of quantum mechanics.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 08:09:20 GMT"
},
{
"version": "v2",
"created": "Sun, 16 Apr 2006 07:46:43 GMT"
},
{
"version": "v3",
"created": "Sun, 10 Sep 2006 02:56:04 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Chen",
"Zeqian",
""
]
] |
quant-ph/0604084
|
Armando Perez
|
C. Navarrete-Benlloch, A. Perez and Eugenio Roldan
|
Nonlinear optical Galton board
|
8 pages, 8 figures
|
Physical Review A 75, 062333 (2007)
|
10.1103/PhysRevA.75.062333
| null |
quant-ph
| null |
We generalize the concept of optical Galton board (OGB), first proposed by
Bouwmeester et al. {[}Phys. Rev. A \textbf{61}, 013410 (2000)], by introducing
the possibility of nonlinear self--phase modulation on the wavefunction during
the walker evolution. If the original Galton board illustrates classical
diffusion, the OGB, which can be understood as a grid of Landau--Zener
crossings, illustrates the influence of interference on diffusion, and is
closely connected with the quantum walk. Our nonlinear generalization of the
OGB shows new phenomena, the most striking of which is the formation of
non-dispersive pulses in the field distribution (soliton--like structures).
These exhibit a variety of dynamical behaviors, including ballistic motion,
dynamical localization, non--elastic collisions and chaotic behavior, in the
sense that the dynamics is very sensitive to the nonlinearity strength.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 08:27:38 GMT"
},
{
"version": "v2",
"created": "Mon, 9 Jul 2007 15:15:35 GMT"
}
] | 2007-07-31T00:00:00 |
[
[
"Navarrete-Benlloch",
"C.",
""
],
[
"Perez",
"A.",
""
],
[
"Roldan",
"Eugenio",
""
]
] |
quant-ph/0604085
|
Daowen Qiu
|
Lvzhou Li, Daowen Qiu
|
A Polynomial-Time Algorithm for the Equivalence between Quantum
Sequential Machines
|
22 pages; some results have been added, while some proofs have been
abbreviated
| null | null | null |
quant-ph
| null |
Quantum sequential machines (QSMs) are a quantum version of stochastic
sequential machines (SSMs). Recently, we showed that two QSMs M_1 and M_2 with
n_1 and n_2 states, respectively, are equivalent iff they are
(n_1+n_2)^2--equivalent (Theoretical Computer Science 358 (2006) 65-74).
However, using this result to check the equivalence likely needs exponential
expected time. In this paper, we consider the time complexity of deciding the
equivalence between QSMs and related problems. The main results are as follows:
(1) We present a polynomial-time algorithm for deciding the equivalence between
QSMs, and, if two QSMs are not equivalent, this algorithm will produce an
input-output pair with length not more than (n_1+n_2)^2. (2) We improve the
bound for the equivalence between QSMs from (n_1+n_2)^2 to n_1^2+n_2^2-1, by
employing Moore and Crutchfield's method (Theoretical Computer Science
237 (2000) 275-306). (3) We give that two MO-1QFAs with n_1 and n_2 states,
respectively, are equivalent iff they are (n_1+n_2)^2--equivalent, and further
obtain a polynomial-time algorithm for deciding the equivalence between two
MO-1QFAs. (4) We provide a counterexample showing that Koshiba's method to
solve the problem of deciding the equivalence between MM-1QFAs may be not
valid, and thus the problem is left open again.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 10:08:18 GMT"
},
{
"version": "v2",
"created": "Mon, 30 Oct 2006 09:02:05 GMT"
}
] | 2016-09-08T00:00:00 |
[
[
"Li",
"Lvzhou",
""
],
[
"Qiu",
"Daowen",
""
]
] |
quant-ph/0604086
|
Hiroo Azuma
|
Hiroo Azuma
|
Quantum computation with Kerr-nonlinear photonic crystals
|
20 pages, Latex2e, 4 eps figures; v2: minor corrections; v3: a new
section added; v4: Sec. 4 is totally rewritten; v5: one section is removed;
v6: minor corrections
|
J. Phys. D: Appl. Phys. 41 (2008) 025102
|
10.1088/0022-3727/41/2/025102
| null |
quant-ph
| null |
In this paper, we consider a method for implementing a quantum logic gate
with photons whose wave function propagates in a one-dimensional Kerr-nonlinear
photonic crystal. The photonic crystal causes the incident photons to undergo
Bragg reflection by its periodic structure of dielectric materials and forms
the photonic band structure, namely, the light dispersion relation. This
dispersion relation reduces the group velocity of the wave function of the
photons, so that it enhances nonlinear interaction of the photons. (Because
variation of the group velocity against the wave vector is very steep, we have
to tune up the wavelength of injected photons precisely, however.) If the
photonic crystal includes layers of a Kerr medium, we can rotate the phase of
the wave function of the incident photons by a large angle efficiently. We show
that we can construct the nonlinear sign-shift (NS) gate proposed by Knill,
Laflamme, and Milburn (KLM) by this method. Thus, we can construct the
conditional sign-flip gate for two qubits, which is crucial for quantum
computation. Our NS gate works with probability unity in principle while KLM's
original one is a nondeterministic gate conditioned on the detection of an
auxiliary photon.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 14:42:45 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Apr 2006 02:37:06 GMT"
},
{
"version": "v3",
"created": "Wed, 12 Jul 2006 06:06:17 GMT"
},
{
"version": "v4",
"created": "Sat, 2 Sep 2006 04:13:18 GMT"
},
{
"version": "v5",
"created": "Sat, 24 Nov 2007 11:37:18 GMT"
},
{
"version": "v6",
"created": "Sat, 22 Dec 2007 00:22:40 GMT"
}
] | 2011-11-09T00:00:00 |
[
[
"Azuma",
"Hiroo",
""
]
] |
quant-ph/0604087
|
Daniela Dragoman
|
Daniela Dragoman
|
On the Quantum-Classical Character of the Quantum Wavefunction of
Material Particles
|
21 pages, no figures
| null | null | null |
quant-ph
| null |
We show that the quantum wavefunction, interpreted as the probability density
of finding a single non-localized quantum particle, which evolves according to
classical laws of motion, is an intermediate description of a material quantum
particle between the quantum and classical realms. Accordingly, classical and
quantum mechanics should not be treated separately, a unified description in
terms of the Wigner distribution function being possible. Although defined on
classical phase space coordinates, the Wigner distribution function
accommodates the nonlocalization property of quantum systems, and leads to both
the Schrodinger equation for the quantum wavefunction and to the definition of
position and momentum operators.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 15:56:48 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Dragoman",
"Daniela",
""
]
] |
quant-ph/0604088
|
Tam\'as V\'ertesi
|
T. V\'ertesi
|
Relative information encoded in the degree of entanglement to
discriminate bipartite states
|
10 pages, no figures. Accepted in Physics Letters A
| null |
10.1016/j.physleta.2006.04.031
| null |
quant-ph
| null |
It has been recently shown (Bartlett et al. 2003) that information encoded
into relative degrees of freedom enables communication without a common
reference frame using entangled bipartite states. In this case the relative
information stored in the two-qubit system is shared between the polarization
degrees of freedom and the degree of entanglement. In the present article a
specific state discrimination problem is envisioned where the degree of
entanglement carries the only relative parameter, so that certain maximally
entangled states are perfectly distinguishable, while discrimination of product
states is impossible.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 17:37:41 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Vértesi",
"T.",
""
]
] |
quant-ph/0604089
|
J. Maurice Rojas
|
J. Maurice Rojas
|
A Number Theoretic Interpolation Between Quantum and Classical
Complexity Classes
|
14 pages, no figures
| null | null | null |
quant-ph math.NT
| null |
We reveal a natural algebraic problem whose complexity appears to interpolate
between the well-known complexity classes BQP and NP:
(*) Decide whether a univariate polynomial with exactly m monomial terms has
a p-adic rational root. In particular, we show that while (*) is doable in
quantum randomized polynomial time when m=2 (and no classical randomized
polynomial time algorithm is known), (*) is nearly NP-hard for general m: Under
a plausible hypothesis involving primes in arithmetic progression (implied by
the Generalized Riemann Hypothesis for certain cyclotomic fields), a randomized
polynomial time algorithm for (*) would imply the widely disbelieved inclusion
NP \subseteq BPP. This type of quantum/classical interpolation phenomenon
appears to new.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 16:40:38 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Apr 2006 20:03:47 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Rojas",
"J. Maurice",
""
]
] |
quant-ph/0604090
|
Barbara M. Terhal
|
Krysta M. Svore, David P. DiVincenzo and Barbara M. Terhal
|
Noise Threshold for a Fault-Tolerant Two-Dimensional Lattice
Architecture
|
20 pages, 11 figures. v2 has some small changes and a link to a
website with supplementary material. v3: Corrects earlier error in fault
tolerant T gate construction. Describes different strategy for non-Clifford
fault tolerance
|
Quant. Inf. Comp. Vol. 7, No. 4, pp. 297-318 (2007)
| null | null |
quant-ph
| null |
We consider a model of quantum computation in which the set of operations is
limited to nearest-neighbor interactions on a 2D lattice. We model movement of
qubits with noisy SWAP operations. For this architecture we design a
fault-tolerant coding scheme using the concatenated [[7,1,3]] Steane code. Our
scheme is potentially applicable to ion-trap and solid-state quantum
technologies. We calculate a lower bound on the noise threshold for our local
model using a detailed failure probability analysis. We obtain a threshold of
1.85 x 10^-5 for the local setting, where memory error rates are one-tenth of
the failure rates of gates, measurement, and preparation steps. For the
analogous nonlocal setting, we obtain a noise threshold of 3.61 x 10^-5. Our
results thus show that the additional SWAP operations required to move qubits
in the local model affect the noise threshold only moderately.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 18:54:04 GMT"
},
{
"version": "v2",
"created": "Fri, 26 May 2006 14:22:00 GMT"
},
{
"version": "v3",
"created": "Fri, 3 Nov 2006 19:04:50 GMT"
}
] | 2008-10-17T00:00:00 |
[
[
"Svore",
"Krysta M.",
""
],
[
"DiVincenzo",
"David P.",
""
],
[
"Terhal",
"Barbara M.",
""
]
] |
quant-ph/0604091
|
Denes Petz
|
Anna Jencova and Denes Petz
|
Sufficiency in quantum statistical inference. A survey with examples
|
23 pages
|
J. Infinite Dimensional Analysis and Quantum Probability, 9(2006),
331-352.
| null | null |
quant-ph
| null |
This paper attempts to give an overview about sufficiency in the setting of
quantum statistics. The basic concepts are treated paralelly to the the measure
theoretic case. It turns out that several classical examples and results have a
non-commutative analogue. Some of the results are presented without proof (but
with exact references) and the presentation is intended to be self-contained.
The main examples discussed in the paper are related the Weyl algebra and to
the exponential family of states. The characterization of sufficiency in terms
of quantum Fisher information is a new result.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 20:12:18 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Jencova",
"Anna",
""
],
[
"Petz",
"Denes",
""
]
] |
quant-ph/0604092
|
Henrique Boschi-Filho
|
P. F. Borges, H. Boschi-Filho and A. N. Vaidya
|
Scattering and Bound State Green's Functions on a Plane via so(2,1) Lie
Algebra
|
21 Latex pages. Typos corrected. Results unchanged. Version to appear
in JMP
|
J.Math.Phys. 47 (2006) 112103
|
10.1063/1.2363259
| null |
quant-ph hep-th
| null |
We calculate the Green's functions for the particle-vortex system, for two
anyons on a plane with and without a harmonic regulator and in a uniform
magnetic field. These Green's functions which describe scattering or bound
states (depending on the specific potential in each case) are obtained exactly
using an algebraic method related to the SO(2,1) Lie group. From these Green's
functions we obtain the corresponding wave functions and for the bound states
we also find the energy spectra.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 20:24:24 GMT"
},
{
"version": "v2",
"created": "Fri, 11 Aug 2006 19:35:12 GMT"
},
{
"version": "v3",
"created": "Tue, 17 Oct 2006 18:42:24 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Borges",
"P. F.",
""
],
[
"Boschi-Filho",
"H.",
""
],
[
"Vaidya",
"A. N.",
""
]
] |
quant-ph/0604093
|
Yuri Golubev
|
T.Golubeva and Yu.Golubev (V. A. Fock Physics Institute,
St.-Petersburg, Russia)
|
Induced photon statistics in three-level lasers
|
13 pages, 2 figures, RevTeX4. Submitted to Phys. Rev. A
|
Physical Review A 75, 023815 ?2007?
|
10.1103/PhysRevA.75.023815
| null |
quant-ph
| null |
The statistical properties of three-level lasing are investigated
theoretically. It is assumed that the three-level medium is coherently excited
by another laser with an arbitrary photon statistics. It is proved that, under
the specific conditions, the photon statistics of the three-level laser
duplicate the photon statistics of the exciting laser. We call this phenomenon
an induced photon statistics. We suggest to use this to analyze the statistical
properties of a laser involved into a feedback process. Applying this laser for
the coherent pump of a three-level laser, we can follow its photon statistics
by means of direct following the three-level generation. In accordance with [H.
M. Wiseman and G. J. Milburn, Phys. Rev. A, 49, 1350-1366 (1994)], we conclude
that the feedback in itself is unable to generate the non-classical
manifestation in the laser field.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 21:05:09 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Golubeva",
"T.",
"",
"V. A. Fock Physics Institute,\n St.-Petersburg, Russia"
],
[
"Golubev",
"Yu.",
"",
"V. A. Fock Physics Institute,\n St.-Petersburg, Russia"
]
] |
quant-ph/0604094
|
Xiongfeng Ma
|
Xiongfeng Ma, Chi-Hang Fred Fung, Fr\'ed\'eric Dupuis, Kai Chen,
Kiyoshi Tamaki and Hoi-Kwong Lo
|
Decoy state quantum key distribution with two-way classical
post-processing
| null |
PHYSICAL REVIEW A 74, 032330 (2006)
|
10.1103/PhysRevA.74.032330
| null |
quant-ph
| null |
Decoy states have recently been proposed as a useful method for substantially
improving the performance of quantum key distribution protocols when a coherent
state source is used. Previously, data post-processing schemes based on one-way
classical communications were considered for use with decoy states. In this
paper, we develop two data post-processing schemes for the decoy-state method
using two-way classical communications. Our numerical simulation (using
parameters from a specific QKD experiment as an example) results show that our
scheme is able to extend the maximal secure distance from 142km (using only
one-way classical communications with decoy states) to 181km. The second scheme
is able to achieve a 10% greater key generation rate in the whole regime of
distances.
|
[
{
"version": "v1",
"created": "Wed, 12 Apr 2006 21:41:38 GMT"
}
] | 2016-08-16T00:00:00 |
[
[
"Ma",
"Xiongfeng",
""
],
[
"Fung",
"Chi-Hang Fred",
""
],
[
"Dupuis",
"Frédéric",
""
],
[
"Chen",
"Kai",
""
],
[
"Tamaki",
"Kiyoshi",
""
],
[
"Lo",
"Hoi-Kwong",
""
]
] |
quant-ph/0604095
|
Ramazan Sever
|
Sameer M. Ikhdair and Ramazan Sever
|
Series Solutions of the N-Dimensional Position-Dependent Mass
Schrodinger Equation with a General Class of Potentials
|
12 pages
| null | null | null |
quant-ph
| null |
The analytical solutions of the N-dimensional Schrodinger equation with
position-dependent mass for a general class of central potentials is obtained
via the series expansion method. The position-dependent mass is expanded in
series about origin. As a special case, the analytical bound-state series
solutions and the recursion relation of the linear-plus-Coulomb (Cornell)
potential with the decaying position-dependent mass m=m_{0}e^{-\lambda r} are
also found.
|
[
{
"version": "v1",
"created": "Thu, 13 Apr 2006 08:22:16 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Ikhdair",
"Sameer M.",
""
],
[
"Sever",
"Ramazan",
""
]
] |
quant-ph/0604096
|
Gen Kimura
|
Gen Kimura, Hajime Tanaka and Masanao Ozawa
|
Solution to the Mean King's problem with mutually unbiased bases for
arbitrary levels
|
REVTeX4, 4 pages
|
Phys. Rev. A 73, 050301(R) (2006).
|
10.1103/PhysRevA.73.050301
| null |
quant-ph
| null |
The Mean King's problem with mutually unbiased bases is reconsidered for
arbitrary d-level systems. Hayashi, Horibe and Hashimoto [Phys. Rev. A 71,
052331 (2005)] related the problem to the existence of a maximal set of d-1
mutually orthogonal Latin squares, in their restricted setting that allows only
measurements of projection-valued measures. However, we then cannot find a
solution to the problem when e.g., d=6 or d=10. In contrast to their result, we
show that the King's problem always has a solution for arbitrary levels if we
also allow positive operator-valued measures. In constructing the solution, we
use orthogonal arrays in combinatorial design theory.
|
[
{
"version": "v1",
"created": "Thu, 13 Apr 2006 10:03:03 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Kimura",
"Gen",
""
],
[
"Tanaka",
"Hajime",
""
],
[
"Ozawa",
"Masanao",
""
]
] |
quant-ph/0604097
|
Yong Li
|
Yong Li, Z. D. Wang, and C. P. Sun
|
Quantum criticality in a generalized Dicke model
|
6 pages, 3 figures
|
Phys. Rev. A 74, 023815 (2006)
|
10.1103/PhysRevA.74.023815
| null |
quant-ph
| null |
We employ a generalized Dicke model to study theoretically the quantum
criticality of an extended two-level atomic ensemble interacting with a
single-mode quantized light field. Effective Hamiltonians are derived and
diagonalized to investigate numerically their eigenfrequencies for different
quantum phases in the system. Based on the analysis of the eigenfrequencies, an
intriguing quantum-phase transition from a normal phase to a superradiant phase
is revealed clearly, which is quite different from that observed with a
standard Dicke model.
|
[
{
"version": "v1",
"created": "Thu, 13 Apr 2006 12:47:03 GMT"
},
{
"version": "v2",
"created": "Mon, 1 Oct 2007 11:39:31 GMT"
}
] | 2007-10-01T00:00:00 |
[
[
"Li",
"Yong",
""
],
[
"Wang",
"Z. D.",
""
],
[
"Sun",
"C. P.",
""
]
] |
quant-ph/0604098
|
Vahid Karimipour
|
F. Ghahhari, V. Karimipour and R. Shahrokhshahi
|
Dynamics of entanglement of bosonic modes on symmetric graphs
|
14 pages, 11 figures, Accepted for publication in Physics Letters A
|
Phys. Lett. A 363 (2007) 271-276.
|
10.1016/j.physleta.2006.11.013
| null |
quant-ph
| null |
We investigate the dynamics of an initially disentangled Gaussian state on a
general finite symmetric graph. As concrete examples we obtain properties of
this dynamics on mean field graphs of arbitrary sizes. In the same way that
chains can be used for transmitting entanglement by their natural dynamics,
these graphs can be used to store entanglement. We also consider two kinds of
regular polyhedron which show interesting features of entanglement sharing.
|
[
{
"version": "v1",
"created": "Thu, 13 Apr 2006 13:30:48 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Nov 2006 04:32:05 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Ghahhari",
"F.",
""
],
[
"Karimipour",
"V.",
""
],
[
"Shahrokhshahi",
"R.",
""
]
] |
quant-ph/0604099
|
Z. D. Wang
|
Xiaoguang Wang and Z. D. Wang
|
Thermal Entanglement in Ferrimagnetic Chains
|
4 pages, 3 figures
|
Phys. Rev. A73, 064302(2006)
|
10.1103/PhysRevA.73.064302
| null |
quant-ph
| null |
A formula to evaluate the entanglement in an one-dimensional ferrimagnetic
system is derived. Based on the formula, we find that the thermal entanglement
in a small size spin-1/2 and spin-s ferrimagnetic chain is rather robust
against temperature, and the threshold temperature may be arbitrarily high when
s is sufficiently large. This intriguing result answers unambiguously a
fundamental question: ``can entanglement and quantum behavior in physical
systems survive at arbitrary high temperatures?"
|
[
{
"version": "v1",
"created": "Thu, 13 Apr 2006 14:27:04 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Wang",
"Xiaoguang",
""
],
[
"Wang",
"Z. D.",
""
]
] |
quant-ph/0604100
|
Efstratios Manousakis
|
Efstratios Manousakis
|
Founding quantum theory on the basis of consciousness
|
41 pages, 3 figures. To be published in Foundations of Physics, Vol
36 (6) (June 2006), published online at
http://dx.doi.org/10.1007/s10701-006-9049-9
|
Found. Phys. 36(6), 795 (2006)
|
10.1007/s10701-006-9049-9
| null |
quant-ph
| null |
In the present work, quantum theory is founded on the framework of
consciousness, in contrast to earlier suggestions that consciousness might be
understood starting from quantum theory. The notion of streams of
consciousness, usually restricted to conscious beings, is extended to the
notion of a Universal/Global stream of conscious flow of ordered events. The
streams of conscious events which we experience constitute sub-streams of the
Universal stream. Our postulated ontological character of consciousness also
consists of an operator which acts on a state of potential consciousness to
create or modify the likelihoods for later events to occur and become part of
the Universal conscious flow. A generalized process of measurement-perception
is introduced, where the operation of consciousness brings into existence, from
a state of potentiality, the event in consciousness. This is mathematically
represented by (a) an operator acting on the state of potential-consciousness
before an actual event arises in consciousness and (b) the reflecting of the
result of this operation back onto the state of potential-consciousness for
comparison in order for the event to arise in consciousness. Beginning from our
postulated ontology that consciousness is primary and from the most elementary
conscious contents, such as perception of periodic change and motion, quantum
theory follows naturally as the description of the conscious experience.
|
[
{
"version": "v1",
"created": "Thu, 13 Apr 2006 14:57:31 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Manousakis",
"Efstratios",
""
]
] |
quant-ph/0604101
|
Kimikazu Kato
|
Kimikazu Kato, Mayumi Oto, Hiroshi Imai and Keiko Imai
|
Voronoi Diagrams for Pure 1-qubit Quantum States
|
7 pages, 2 figures. Talk presented at "International Symposium on
Voronoi Diagrams in Science and Engineering 2005"
| null | null | null |
quant-ph
| null |
1-qubit quantum states form a space called the three-dimensional Bloch ball.
To compute Holevo capacity, Voronoi diagrams in the Bloch ball with respect to
the quantum divergence have been used as a powerful tool. These diagrams
basically treat mixed quantum states corresponding to points in the interior of
the Bloch ball. Due to the existence of logarithm in the quantum divergence,
the diagrams are not defined on pure quantum states corresponding to points on
the two-dimensional sphere. This paper first defines the Voronoi diagrams for
pure quantum states on the Bloch sphere by the Fubini-Study distance and the
Bures distance. We also introduce other Voronoi diagrams on the sphere obtained
by taking a limit of Voronoi diagrams for mixed quantum states by the quantum
divergences in the Bloch ball. These diagrams are shown to be equivalent to the
ordinary Voronoi diagram on the sphere.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 02:00:34 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Kato",
"Kimikazu",
""
],
[
"Oto",
"Mayumi",
""
],
[
"Imai",
"Hiroshi",
""
],
[
"Imai",
"Keiko",
""
]
] |
quant-ph/0604102
|
Andreas Klappenecker
|
Salah A. Aly, Andreas Klappenecker, Pradeep Kiran Sarvepalli
|
On Quantum and Classical BCH Codes
|
17 pages, LaTeX
| null | null | null |
quant-ph
| null |
Classical BCH codes that contain their (Euclidean or Hermitian) dual codes
can be used to construct quantum stabilizer codes; this correspondence studies
the properties of such codes. It is shown that a BCH code of length n can
contain its dual code only if its designed distance d=O(sqrt(n)), and the
converse is proved in the case of narrow-sense codes. Furthermore, the
dimension of narrow-sense BCH codes with small design distance is completely
determined, and - consequently - the bounds on their minimum distance are
improved. These results make it possible to determine the parameters of quantum
BCH codes in terms of their design parameters.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 05:09:29 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Aly",
"Salah A.",
""
],
[
"Klappenecker",
"Andreas",
""
],
[
"Sarvepalli",
"Pradeep Kiran",
""
]
] |
quant-ph/0604103
|
Fu Jian
|
Jian Fu
|
A novel interferometer to beat the standard quantum limit using optical
transverse modes in multimode waveguide
|
9 pages, 3 figures,some errors corrected
| null | null | null |
quant-ph
| null |
We propose a novel interferometer by using optical transverse modes in
multimode waveguide that can beat the standard quantum limit. In the scheme,
the classical simulation of $N$-partical quantum entangled states is generated
by using $N$ independent classical fields and linear optical elements. Similar
to the quantum-enhanced measurements, the classical simulation can also achieve
$\sqrt{N}$ enhancement over the precision of the measurement $N$ times for
independent fields. Due to only using classical fields and linear optical
elements, the scheme can be realized much more easily.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 05:50:18 GMT"
},
{
"version": "v2",
"created": "Tue, 2 May 2006 08:45:26 GMT"
},
{
"version": "v3",
"created": "Wed, 3 May 2006 06:52:45 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Fu",
"Jian",
""
]
] |
quant-ph/0604104
|
Manas Patra
|
Manas Patra
|
Projective invariant measures and approximation of quantum circuits
|
17 pages
| null | null | null |
quant-ph
| null |
In this paper we introduce a projective invarinat measure on the special
unitary group. It is directly related to transition probabilities. It has some
interesting connection with convex geometry. Applications to approximation of
quantum circuits and entanglement are given.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 07:22:03 GMT"
},
{
"version": "v2",
"created": "Sat, 15 Apr 2006 05:31:58 GMT"
},
{
"version": "v3",
"created": "Tue, 18 Apr 2006 15:02:29 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Patra",
"Manas",
""
]
] |
quant-ph/0604105
|
Manas Patra
|
Manas Patra
|
Estimating Information Gain in Measurements in Suboptimal Bases for
Quantum State Tomography
|
13 pages
| null | null | null |
quant-ph
| null |
It is known that mutually unbiased bases, whenever they exist, are optimal in
an information theoretic sense for the determination of unknown state of a
quantum ensemble. These bases may not exist in most dimensions and some
suboptimal choices have to be made. The present paper deals with estimates of
the information loss in suboptimal choice of bases. The information is
calculated directly in terms of transition probabilities. I give estimates for
the information content of measurement in some approximate MUBs proposed
recently.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 07:31:47 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Apr 2006 15:09:17 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Patra",
"Manas",
""
]
] |
quant-ph/0604106
|
Omar Mustafa
|
Omar Mustafa and S. Habib Mazharimousavi
|
$\eta$-weak-Pseudo-Hermiticity generators and exact solvability
|
8 pages, no figures, to appear in Phys. Lett. A
|
Phys.Lett. A357 (2006) 295-297
|
10.1016/j.physleta.2006.06.027
| null |
quant-ph
| null |
Exact solvability of some non-Hermitian $\eta$-weak-pseudo-Hermitian
Hamiltonians is explored as a byproduct of $\eta$-weak-pseudo-Hermiticity
generators. A class of V_{eff}(x)=V(x)+iW(x) potentials is considered, where
the imaginary part W(x) is used as an $\eta$-weak-pseudo-Hermiticity generator
to obtain exactly solvable $\eta$-weak-pseudo-Hermitian Hamiltonian models.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 09:35:36 GMT"
},
{
"version": "v2",
"created": "Sun, 4 Jun 2006 11:33:04 GMT"
},
{
"version": "v3",
"created": "Mon, 12 Jun 2006 12:02:54 GMT"
},
{
"version": "v4",
"created": "Tue, 13 Jun 2006 09:43:14 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Mustafa",
"Omar",
""
],
[
"Mazharimousavi",
"S. Habib",
""
]
] |
quant-ph/0604107
|
Graeme Smith
|
Graeme Smith and John A. Smolin
|
Degenerate Quantum Codes for Pauli Channels
|
Introduction changed to give more motivation and background. Figure 1
replaced
|
Phys. Rev. Lett. 98, 030501 (2007)
|
10.1103/PhysRevLett.98.030501
| null |
quant-ph
| null |
A striking feature of quantum error correcting codes is that they can
sometimes be used to correct more errors than they can uniquely identify. Such
degenerate codes have long been known, but have remained poorly understood. We
provide a heuristic for designing degenerate quantum codes for high noise
rates, which is applied to generate codes that can be used to communicate over
almost any Pauli channel at rates that are impossible for a nondegenerate code.
The gap between nondegenerate and degenerate code performance is quite large,
in contrast to the tiny magnitude of the only previous demonstration of this
effect. We also identify a channel for which none of our codes outperform the
best nondegenerate code and show that it is nevertheless quite unlike any
channel for which nondegenerate codes are known to be optimal.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 20:05:58 GMT"
},
{
"version": "v2",
"created": "Sat, 23 Dec 2006 15:57:58 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Smith",
"Graeme",
""
],
[
"Smolin",
"John A.",
""
]
] |
quant-ph/0604108
|
Hong Shen
|
Xiao-Feng Qian, Z. Song
|
Relation between two measures of entanglement in spin-1/2 and spinless
fermion quantum chain systems
|
7 pages, no figures, publication version, to appear in PRA
|
Phys. Rev. A 74, 022302 (2006)
|
10.1103/PhysRevA.74.022302
| null |
quant-ph
| null |
The concepts of concurrence and mode concurrence are the measures of
entanglement for spin-1/2 and spinless fermion systems respectively. Based on
the Jordan-Wigner transformation, any spin-1/2 system is always associated with
a fermion system (called counterpart system). The comparison of concurrence and
mode concurrence can be made with the aid of the Marshall's sign rule for the
ground states of spin-1/2 $XXZ$ and spinless fermion chain systems. We observe
that there exists an inequality between concurrence and mode concurrence for
the ground states of the two corresponding systems. The spin-1/2 XY chain
system and its spinless fermion counterpart as a realistic example is discussed
to demonstrate the analytical results.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 22:15:03 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Jul 2006 02:18:29 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Qian",
"Xiao-Feng",
""
],
[
"Song",
"Z.",
""
]
] |
quant-ph/0604109
|
Remigiusz Augusiak
|
Remigiusz Augusiak, Maciej Demianowicz, Pawel Horodecki
|
Universal observable detecting all two-qubit entanglement and
determinant based separability tests
|
5 pages, RevTeX, one figure replaced by another, tight bounds on
negativity and concurrence added, function proved to be a monotone under the
pure LOCC, list of authors put in alphabetical order
|
Physical Review A 77, 030301(R) (2008)
|
10.1103/PhysRevA.77.030301
| null |
quant-ph
| null |
We construct a single observable measurement of which mean value on four
copies of an {\it unknown} two-qubit state is sufficient for unambiguous
decision whether the state is separable or entangled. In other words, there
exists a universal collective entanglement witness detecting all two-qubit
entanglement. The test is directly linked to a function which characterizes to
some extent the entanglement quantitatively. This function is an entanglement
monotone under so--called local pure operations and classical communication
(pLOCC) which preserve local dimensions. Moreover it provides tight upper and
lower bounds for negativity and concurrence. Elementary quantum computing
device estimating unknown two-qubit entanglement is designed.
|
[
{
"version": "v1",
"created": "Fri, 14 Apr 2006 22:51:04 GMT"
},
{
"version": "v2",
"created": "Mon, 29 Oct 2007 17:25:28 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Augusiak",
"Remigiusz",
""
],
[
"Demianowicz",
"Maciej",
""
],
[
"Horodecki",
"Pawel",
""
]
] |
quant-ph/0604110
|
Jalani Kanem
|
J.F. Kanem, S. Maneshi, M. Partlow, M. Spanner and A.M. Steinberg
|
Observation of high-order quantum resonances in the kicked rotor
| null |
Phys.Rev.Lett. 98, 083004 (2007)
|
10.1103/PhysRevLett.98.083004
| null |
quant-ph
| null |
Quantum resonances in the kicked rotor are characterized by a dramatically
increased energy absorption rate, in stark contrast to the momentum
localization generally observed. These resonances occur when the scaled
Planck's constant hbar=(r/s)*4pi, for any integers r and s. However only the
hbar=r*2pi resonances are easily observable. We have observed high-order
quantum resonances (s>2) utilizing a sample of low temperature, non-condensed
atoms and a pulsed optical standing wave. Resonances are observed for
hbar=(r/16)*4pi r=2-6. Quantum numerical simulations suggest that our
observation of high-order resonances indicates a larger coherence length than
expected from an initially thermal atomic sample.
|
[
{
"version": "v1",
"created": "Sat, 15 Apr 2006 23:12:16 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Kanem",
"J. F.",
""
],
[
"Maneshi",
"S.",
""
],
[
"Partlow",
"M.",
""
],
[
"Spanner",
"M.",
""
],
[
"Steinberg",
"A. M.",
""
]
] |
quant-ph/0604111
|
Arul Lakshminarayan
|
Krishnendu Maity and Arul Lakshminarayan
|
Quantum chaos in the spectrum of operators used in Shor's algorithm
|
Title and paper modified to include interesting additional
possibilities. Principal results unaffected. Accepted for publication in
Phys. Rev. E as Rapid Comm
|
Phys. Rev. E. vol. 74, 035203(R) (2006).
|
10.1103/PhysRevE.74.035203
|
IITM/PH/TH/2006/5
|
quant-ph nlin.CD
| null |
We provide compelling evidence for the presence of quantum chaos in the
unitary part of Shor's factoring algorithm. In particular we analyze the
spectrum of this part after proper desymmetrization and show that the
fluctuations of the eigenangles as well as the distribution of the eigenvector
components follow the CUE ensemble of random matrices, of relevance to
quantized chaotic systems that violate time-reversal symmetry. However, as the
algorithm tracks the evolution of a single state, it is possible to employ
other operators, in particular it is possible that the generic quantum chaos
found above becomes of a nongeneric kind such as is found in the quantum cat
maps, and in toy models of the quantum bakers map.
|
[
{
"version": "v1",
"created": "Sun, 16 Apr 2006 05:59:47 GMT"
},
{
"version": "v2",
"created": "Mon, 28 Aug 2006 07:48:32 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Maity",
"Krishnendu",
""
],
[
"Lakshminarayan",
"Arul",
""
]
] |
quant-ph/0604112
|
Yasushi Kondo Dr.
|
Yasushi Kondo, Mikio Nakahara, and Shogo Tanimura
|
Artificial Decoherence and its Suppression in NMR Quantum Computer
|
Article presented at QIT13 workshop in November 24, 2005 V1 did not
create a correct PS or PDF file in the acXiv system. 6 figures
| null | null | null |
quant-ph
| null |
Liquid-state NMR quantum computer has demonstrated the possibility of quantum
computation and supported its development. Using NMR quantum computer
techniques, we observed phase decoherence under two kinds of artificial noise
fields; one a noise with a long period, and the other with shorter random
period. The first one models decoherence in a quantum channel while the second
one models transverse relaxation. We demonstrated that the bang-bang control
suppresses decoherence in both cases.
|
[
{
"version": "v1",
"created": "Sun, 16 Apr 2006 13:03:01 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Apr 2006 02:07:48 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Kondo",
"Yasushi",
""
],
[
"Nakahara",
"Mikio",
""
],
[
"Tanimura",
"Shogo",
""
]
] |
quant-ph/0604113
|
Yaron Bromberg
|
Barak Dayan, Yaron Bromberg, Itai Afek, and Yaron Silberberg
|
Spectral Polarization and Spectral Phase Control of Time and Energy
Entangled Photons
|
5 pages, 3 figures
|
Phys. Rev. A. 75, 043804 (2007)
|
10.1103/PhysRevA.75.043804
| null |
quant-ph
| null |
We demonstrate a scheme to spectrally manipulate a collinear, continuous
stream of time and energy entangled photons to generate beamlike,
bandwidth-limited fuxes of polarization-entangled photons with
nearly-degenerate wavelengths. Utilizing an ultrashort-pulse shaper to control
the spectral phase and polarization of the photon pairs, we tailor the shape of
the Hong-Ou-Mandel interference pattern, demonstrating the rules that govern
the dependence of this interference pattern on the spectral phases of the
photons. We then use the pulse shaper to generate all four polarization Bell
states. The singlet state generated by this scheme forms a very robust
decoherence-free subspace, extremely suitable for long distance fiber-optics
based quantum communication.
|
[
{
"version": "v1",
"created": "Sun, 16 Apr 2006 17:30:33 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Apr 2007 04:51:37 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Dayan",
"Barak",
""
],
[
"Bromberg",
"Yaron",
""
],
[
"Afek",
"Itai",
""
],
[
"Silberberg",
"Yaron",
""
]
] |
quant-ph/0604114
|
Masoud Mohseni
|
M. Mohseni and D. A. Lidar
|
Reply to M. Ziman's "Notes on optimality of direct characterization of
quantum dynamics"
| null | null | null | null |
quant-ph
| null |
Recently M. Ziman [quant-ph/0603151] criticized our approach for quantifying
the required physical resources in the theory of Direct Characterization of
Quantum Dynamics (DCQD) [quant-ph/0601033, quant-ph/0601034] in comparison to
other quantum process tomography (QPT) schemes. Here we argue that Ziman's
comments regarding optimality, quantumness, and the novelty of DCQD are
inaccurate. Specifically, we demonstrate that DCQD is optimal with respect to
both the required number of experimental configurations and the number of
possible outcomes over all known QPT schemes in the 2^{2n} dimensional Hilbert
space of n system and n ancilla qubits. Moreover, we show DCQD is more
efficient than all known QPT schemes in the sense of overall required number of
quantum operations. Furthermore, we argue that DCQD is a new method for
characterizing quantum dynamics and cannot be considered merely as a subclass
of previously known QPT schemes.
|
[
{
"version": "v1",
"created": "Sun, 16 Apr 2006 22:36:43 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Mohseni",
"M.",
""
],
[
"Lidar",
"D. A.",
""
]
] |
quant-ph/0604115
|
Kazuyuki Fujii
|
Kazuyuki Fujii and Hiroshi Oike
|
How to Calculate the Exponential of Matrices
|
Latex ; 15 pages ; 1 figure. The result is not new unfortunately,
while the method is elementary and new. Since the formula is very convenient,
it may be worth recording
|
Far East Journal of Mathematical Education, 9(2012) 39-55
| null | null |
quant-ph math-ph math.MP
| null |
How to calculate the exponential of matrices in an explicit manner is one of
fundamental problems in almost all subjects in Science.
Especially in Mathematical Physics or Quantum Optics many problems are
reduced to this calculation by making use of some approximations whether they
are appropriate or not. However, it is in general not easy.
In this paper we give a very useful formula which is both elementary and
getting on with computer.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 01:11:10 GMT"
}
] | 2012-07-27T00:00:00 |
[
[
"Fujii",
"Kazuyuki",
""
],
[
"Oike",
"Hiroshi",
""
]
] |
quant-ph/0604116
|
Kazuya Yuasa
|
Kazuya Yuasa
|
Derivation of Master Equations in the Presence of Initial Correlations
with Reservoir: Projection Method Revisited
|
10 pages; Contribution to the Proceedings of TQMFA05, Palermo, 2005
| null | null | null |
quant-ph
| null |
We discuss the derivation of master equations in the presence of initial
correlations with the reservoir. In van Hove's limit, the total system behaves
as if it started from a factorized initial condition. A proper choice of
Nakajima-Zwanzig's projection operator is crucial and the reservoir should be
endowed with the mixing property.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 03:53:49 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Yuasa",
"Kazuya",
""
]
] |
quant-ph/0604117
|
Thomas Durt
|
Thomas Durt
|
Tomography of one and two qubit states and factorisation of the Wigner
distribution in prime power dimensions
|
24 pages
| null | null | null |
quant-ph
| null |
We study different techniques that allow us to gain complete knowledge about
an unknown quantum state, e.g. to perform full tomography of this state. We
focus on two apparently simple cases, full tomography of one and two qubit
systems. We analyze and compare those techniques according to two figures of
merit. Our first criterion is the minimisation of the redundancy of the data
acquired during the tomographic process. In the case of two-qubits tomography,
we also analyze this process from the point of view of factorisability, so to
say we analyze the possibility to realise the tomographic process through local
operations and classical communications between local observers. This brings us
naturally to study the possibility to factorize the (discrete) Wigner
distribution of a composite system into the product of local Wigner
distributions. The discrete Heisenberg-Weyl group is an essential ingredient of
our approach. Possible extensions of our results to higher dimensions are
discussed in the last section and in the conclusions.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 06:32:54 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Durt",
"Thomas",
""
]
] |
quant-ph/0604118
|
Quesne Christiane
|
C. Quesne, V. M. Tkachuk
|
Lorentz-covariant deformed algebra with minimal length and application
to the 1+1-dimensional Dirac oscillator
|
20 pages, no figure, some very small changes, published version
|
J.Phys.A39:10909-10922,2006
|
10.1088/0305-4470/39/34/021
|
ULB/229/CQ/06/2
|
quant-ph hep-th math-ph math.MP math.QA
| null |
The $D$-dimensional $(\beta, \beta')$-two-parameter deformed algebra
introduced by Kempf is generalized to a Lorentz-covariant algebra describing a
($D+1$)-dimensional quantized space-time. In the D=3 and $\beta=0$ case, the
latter reproduces Snyder algebra. The deformed Poincar\'e transformations
leaving the algebra invariant are identified. It is shown that there exists a
nonzero minimal uncertainty in position (minimal length). The Dirac oscillator
in a 1+1-dimensional space-time described by such an algebra is studied in the
case where $\beta'=0$. Extending supersymmetric quantum mechanical and
shape-invariance methods to energy-dependent Hamiltonians provides exact
bound-state energies and wavefunctions. Physically acceptable states exist for
$\beta < 1/(m^2 c^2)$. A new interesting outcome is that, in contrast with the
conventional Dirac oscillator, the energy spectrum is bounded.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 12:47:13 GMT"
},
{
"version": "v2",
"created": "Wed, 9 Aug 2006 11:59:39 GMT"
}
] | 2011-07-19T00:00:00 |
[
[
"Quesne",
"C.",
""
],
[
"Tkachuk",
"V. M.",
""
]
] |
quant-ph/0604119
|
Paolo Amore Dr
|
Paolo Amore, Francisco M. Fernandez
|
Application of the Asymptotic Iteration Method to a Perturbed Coulomb
Model
|
9 pages, 2 figures, 1 table
|
Journal of Physics A 39, 10491-10497 (2006)
|
10.1088/0305-4470/39/33/016
| null |
quant-ph
| null |
We show that the asymptotic iteration method converges and yields accurate
energies for a perturbed Coulomb model. We also discuss alternative
perturbation approaches to that model.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 15:09:56 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Amore",
"Paolo",
""
],
[
"Fernandez",
"Francisco M.",
""
]
] |
quant-ph/0604120
|
Gour Pati
|
M.S. Shahriar, P. Pradhan, G.S. Pati, V. Gopal, and K. Salit
|
Light-Shift Imbalance Induced Blockade of Collective Excitations Beyond
the Lowest Order
|
6 pages, 5 figures
| null |
10.1016/j.optcom.2007.05.057
| null |
quant-ph
| null |
Current proposals focusing on neutral atoms for quantum computing are mostly
based on using single atoms as quantum bits (qubits), while using cavity
induced coupling or dipole-dipole interaction for two-qubit operations. An
alternative approach is to use atomic ensembles as qubits. However, when an
atomic ensemble is excited, by a laser beam matched to a two-level transition
(or a Raman transition) for example, it leads to a cascade of many states as
more and more photons are absorbed^1. In order to make use of an ensemble as a
qubit, it is necessary to disrupt this cascade, and restrict the excitation to
the absorption (and emission) of a single photon only. Here, we show how this
can be achieved by using a new type of blockade mechanism, based on the
light-shift imbalance (LSI) in a Raman transition. We describe first a simple
example illustrating the concept of light shift imbalanced induced blockade
(LSIIB) using a multi-level structure in a single atom, and show verifications
of the analytic prediction using numerical simulations. We then extend this
model to show how a blockade can be realized by using LSI in the excitation of
an ensemble. Specifically, we show how the LSIIB process enables one to treat
the ensemble as a two level atom that undergoes fully deterministic Rabi
oscillations between two collective quantum states, while suppressing
excitations of higher order collective states.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 16:13:58 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Apr 2006 02:54:43 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Shahriar",
"M. S.",
""
],
[
"Pradhan",
"P.",
""
],
[
"Pati",
"G. S.",
""
],
[
"Gopal",
"V.",
""
],
[
"Salit",
"K.",
""
]
] |
quant-ph/0604121
|
Gour Pati
|
M.S. Shahriar, G.S. Pati, and K. Salit
|
Quantum Communication and Computing With Atomic Ensembles Using
Light-Shift Imbalance Induced Blockade
|
16 pages, 9 figures. Accepted in Phys. Rev. A
| null |
10.1103/PhysRevA.75.022323
| null |
quant-ph
| null |
Recently, we have shown that for conditions under which the so-called
light-shift imbalance induced blockade (LSIIB) occurs, the collective
excitation of an ensemble of a multi-level atom can be treated as a closed two
level system. In this paper, we describe how such a system can be used as a
quantum bit (qubit) for quantum communication and quantum computing.
Specifically, we show how to realize a C-NOT gate using the collective qubit
and an easily accessible ring cavity, via an extension of the so-called
Pellizzari scheme. We also describe how multiple, small-scale quantum computers
realized using these qubits can be linked effectively for implementing a
quantum internet. We describe the details of the energy levels and transitions
in 87Rb atom that could be used for implementing these schemes.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 16:46:16 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Apr 2006 02:57:35 GMT"
},
{
"version": "v3",
"created": "Fri, 22 Dec 2006 16:59:18 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Shahriar",
"M. S.",
""
],
[
"Pati",
"G. S.",
""
],
[
"Salit",
"K.",
""
]
] |
quant-ph/0604122
|
Stephen Adler
|
Stephen L. Adler
|
Notes on the Conway-Kochen Twin Argument
|
TEX, 6 pages Revised to withdraw my objections to the C-K argument
| null | null | null |
quant-ph
| null |
This is a revision of my original posting, in which I raised objections to
part of the Conway-Kochen argument. I now agree with them that their recent
reply answers my original concerns. In the first part of these notes (identical
to the original), I give a reformulation of the part of the Conway-Kochen
result that closes the contextuality loophole in the original Kochen-Specker
(KS) theorem. In the second part (modified in this revision) I review my
concerns connected with the finite time needed to make a measurement, and
briefly indicate how Conway and Kochen have reponded to them.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 20:31:49 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Oct 2006 18:02:42 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Adler",
"Stephen L.",
""
]
] |
quant-ph/0604123
|
Guido A. Raggio
|
M.E. Gabach Clement, and G.A. Raggio
|
A simple spectral condition implying separability for states of
bipartite quantum systems
|
5 pages Revised 31 May 2006
| null |
10.1088/0305-4470/39/29/019
| null |
quant-ph
| null |
For two qubits and for general bipartite quantum systems, we give a simple
spectral condition in terms of the ordered eigenvalues of the density matrix
which guarantees that the corresponding state is separable.
|
[
{
"version": "v1",
"created": "Mon, 17 Apr 2006 21:15:29 GMT"
},
{
"version": "v2",
"created": "Wed, 31 May 2006 17:40:54 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Clement",
"M. E. Gabach",
""
],
[
"Raggio",
"G. A.",
""
]
] |
quant-ph/0604124
|
A. F. Kracklauer
|
A. F. Kracklauer
|
What's wrong with this rebuttal?
|
2 pages
|
Found. Phys. Lett., 19 (6), 625-629 (2006)
|
10.1007/s10702-006-1016-3
| null |
quant-ph
| null |
A recent rebuttal to criticism of Bell's analysis is shown to be defective by
fault of failure to consider all hypothetical conditions input into the
derivation of Bell Inequalitites.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 00:32:20 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Oct 2006 13:45:39 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Kracklauer",
"A. F.",
""
]
] |
quant-ph/0604125
|
Zhang Zhanjun Dr.
|
Zhan-jun Zhang
|
Improving the security of quantum direct communication with
authentication
|
Any suggestion,comment or help is welcome!
| null |
10.1103/PhysRevA.75.026301
| null |
quant-ph
| null |
Two protocols of quantum direct communication with authentication [Phys. Rev.
A {\bf 73}, 042305 (2006)] are recently proposed by Lee, Lim and Yang. In this
paper we will show that in the two protocols the authenticator Trent should be
prevented from knowing the secret message of communication. The first protocol
can be eavesdropped by Trent using the the intercept-measure-resend attack,
while the second protocol can be eavesdropped by Trent using single-qubit
measurement. To fix these leaks, I revise the original versions of the
protocols by using the Pauli-Z operation $\sigma_z$ instead of the original
bit-flip operation $X$. As a consequence, the protocol securities are improved.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 02:06:10 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Apr 2006 13:55:59 GMT"
}
] | 2013-05-29T00:00:00 |
[
[
"Zhang",
"Zhan-jun",
""
]
] |
quant-ph/0604126
|
Haret Rosu
|
Jorge C. Navarro-Munoz, H.C. Rosu, R. Lopez-Sandoval
|
Genetic algorithm optimization of entanglement
|
26 pages with 13 figures, based on Chapter 3 of the Master thesis of
the first author defended at IPICyT, San Luis Potosi, Mx, on 22nd of February
2006, similar to the published version [Fig. 5 left out but contains the
Appendix figure]
|
Phys. Rev. A 74, 052308 (Nov. 2006)
|
10.1103/PhysRevA.74.052308
| null |
quant-ph
| null |
We present an application of a genetic algorithmic computational method to
the optimization of the concurrence measure of entanglement for the cases of
one dimensional chains, as well as square and triangular lattices in a simple
tight-binding approach in which the hopping of electrons is much stronger than
the phonon dissipation
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 01:53:49 GMT"
},
{
"version": "v2",
"created": "Mon, 13 Nov 2006 08:37:44 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Navarro-Munoz",
"Jorge C.",
""
],
[
"Rosu",
"H. C.",
""
],
[
"Lopez-Sandoval",
"R.",
""
]
] |
quant-ph/0604127
|
Levon Mardoyan G
|
L.G. Mardoyan and M.G. Petrosyan
|
4D singular oscillator and generalized MIC-Kepler system
|
6 pages
|
Phys.Atom.Nucl.70:572-575,2007
|
10.1134/S1063778807030180
| null |
quant-ph hep-th
| null |
It is shown that the generalized MIC-Kepler system and four-dimensional
singular oscillator are dual to each other and the duality transformation is
the generalized version of the Kustaanheimo-Stiefel transformation.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 06:38:17 GMT"
}
] | 2008-11-26T00:00:00 |
[
[
"Mardoyan",
"L. G.",
""
],
[
"Petrosyan",
"M. G.",
""
]
] |
quant-ph/0604128
|
Zhi-Ming Zhang
|
Zhi-Ming Zhang
|
Generating superposition and entanglement of squeezed vacuum states
|
5 pages, 3 figures
| null | null | null |
quant-ph
| null |
We propose a scheme for generating the superposition and the entanglement of
squeezed vacuum states of electromagnetical fields. The scheme involves
single-photon source, single photon detector, and cross Kerr nonlinearity. The
Kerr nonlinearity required for generating the superposition of squeezed vacuum
states is 1/2 of that required for generating the superposition of coherent
states. The proposal can also be extended to generate the entanglement states
between two coherent states and that between one coherent state and one
squeezed vacuum state.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 08:46:55 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Zhang",
"Zhi-Ming",
""
]
] |
quant-ph/0604129
|
Ting Gao
|
Ting Gao, Feng-Li Yan, Zhi-Xi Wang, You-Cheng Li
|
Capacity of a simultaneous quantum secure direct communication scheme
between the central party and other M parties
|
3 pages
|
Chinese Physics Letters, 23 (2006) 2656
|
10.1088/0256-307X/23/10/009
| null |
quant-ph
| null |
We analyze the capacity of a simultaneous quantum secure direct communication
scheme between the central party and other $M$ parties via $M+1$-particle GHZ
states and swapping quantum entanglement. It is shown that the encoding scheme
should be secret if other $M$ parties wants to transmit $M+1$ bit classical
messages to the center party secretly. However when the encoding scheme is
announced publicly, we prove that the capacity of the scheme in transmitting
the secret messages is 2 bits, no matter how big $M$ is.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 12:29:01 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Gao",
"Ting",
""
],
[
"Yan",
"Feng-Li",
""
],
[
"Wang",
"Zhi-Xi",
""
],
[
"Li",
"You-Cheng",
""
]
] |
quant-ph/0604130
|
Mireille Calvet
|
Roland Omnes
|
Decoherence and reduction
| null | null | null | null |
quant-ph
| null |
A reduction mechanism resulting directly from the basic principles of quantum
mechanics is proposed, inseparably from decoherence. A rather consistent theory
of this effect is given and the next problems it raises are indicated.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 13:17:06 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Omnes",
"Roland",
""
]
] |
quant-ph/0604131
|
Mark Jones
|
Mark A G Jones, Kyriakos Porfyrakis, G Andrew D Briggs, Robert A
Taylor, Arzhang Ardavan
|
Direct optical excitation of a fullerene-incarcerated metal ion
| null |
Chem. Phys. Lett. 428, 303 (2006)
|
10.1016/j.cplett.2006.06.094
| null |
quant-ph
| null |
The endohedral fullerene Er3N@C80 shows characteristic 1.5 micron
photoluminescence at cryogenic temperatures associated with radiative
relaxation from the crystal-field split Er3+ 4I13/2 manifold to the 4I15/2
manifold. Previous observations of this luminescence were carried out by
photoexcitation of the fullerene cage states leading to relaxation via the
ionic states. We present direct non-cage-mediated optical interaction with the
erbium ion. We have used this interaction to complete a
photoluminescence-excitation map of the Er3+ 4I13/2 manifold. This ability to
interact directly with the states of an incarcerated ion suggests the
possibility of coherently manipulating fullerene qubit states with light.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 13:43:01 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Apr 2006 09:39:46 GMT"
},
{
"version": "v3",
"created": "Thu, 20 Apr 2006 11:51:45 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Jones",
"Mark A G",
""
],
[
"Porfyrakis",
"Kyriakos",
""
],
[
"Briggs",
"G Andrew D",
""
],
[
"Taylor",
"Robert A",
""
],
[
"Ardavan",
"Arzhang",
""
]
] |
quant-ph/0604132
|
Mankei Tsang
|
Mankei Tsang
|
Beating the spatial standard quantum limits via adiabatic soliton
expansion
|
4 pages, 1 figure, v2: omitted the requirement of negative refraction
| null | null | null |
quant-ph
| null |
Spatial quantum enhancement effects are studied under a unified framework. It
is shown that the multiphoton absorption rate of photons with a
quantum-enhanced lithographic resolution is reduced, not enhanced, contrary to
popular belief. The use of adiabatic soliton expansion is proposed to beat the
standard quantum limit on the optical beam displacement accuracy, as well as to
engineer an arbitrary multiphoton interference pattern for quantum lithography.
The proposed scheme provides a conceptually simple method that works for an
arbitrary number of photons.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 19:00:28 GMT"
},
{
"version": "v2",
"created": "Tue, 9 May 2006 02:15:37 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Tsang",
"Mankei",
""
]
] |
quant-ph/0604133
|
Alan Forrester
|
Alan Forrester
|
Decision theory and information propagation in quantum physics
|
minor corrections, to appear in Studies in the History and Philosophy
of Modern Physics, 35 pages
|
Studies In History and Philosophy of Science Part B: Studies In
History and Philosophy of Modern Physics, Vol, 38, No. 4, Dec 2007, 815-831
|
10.1016/j.shpsb.2007.02.004
| null |
quant-ph physics.hist-ph
| null |
In recent papers, Zurek has objected to the decision-theoretic approach of
Deutsch and Wallace to deriving the Born rule for quantum probabilities on the
grounds that it courts circularity. Deutsch and Wallace assume that the many
worlds theory is true and that decoherence gives rise to a preferred basis.
However, decoherence arguments use the reduced density matrix, which relies
upon the partial trace and hence upon the Born Rule for its validity. Using the
Heisenberg Picture and quantum Darwinism - the notion that classical
information is quantum information that can proliferate in the environment
pioneered by Olliver et al - I show that measurement interactions between two
systems only create correlations between a specific set of commuting
observables of system 1 and a specific set of commuting observables of system
2. This argument picks out a unique basis in which information flows in the
correlations between those sets of commuting observables. I then derive the
Born rule for both pure and mixed states and answer some other criticisms of
the decision theoretic approach to quantum probability.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 19:00:35 GMT"
},
{
"version": "v2",
"created": "Tue, 24 Oct 2006 19:59:02 GMT"
},
{
"version": "v3",
"created": "Sun, 11 Feb 2007 01:16:58 GMT"
},
{
"version": "v4",
"created": "Wed, 25 Apr 2007 20:11:40 GMT"
}
] | 2008-11-22T00:00:00 |
[
[
"Forrester",
"Alan",
""
]
] |
quant-ph/0604134
|
Olivier Pfister
|
Jietai Jing, Sheng Feng, Russell Bloomer, Olivier Pfister
|
Experimental continuous-variable entanglement from a
phase-difference-locked optical parametric oscillator
|
4 pages, 4 figures, submitted for publication
|
PRA 74, 041804(R) (2006)
|
10.1103/PhysRevA.74.041804
| null |
quant-ph
| null |
We observed continuous-variable entanglement between the bright beams emitted
above threshold by an ultrastable optical parametric oscillator, classically
phase-locked at a frequency difference of 161.8273240(5) MHz. The
amplitude-difference squeezing is -3 dB and the phase-sum one is -1.35 dB.
Besides proving entanglement in a new physical system, the phase-locked OPO,
such unprecedented frequency-difference stability paves the way for
transferring entanglement between different optical frequencies and densely
implementing continuous-variable quantum information in the frequency domain.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 19:55:21 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Apr 2006 16:27:27 GMT"
},
{
"version": "v3",
"created": "Mon, 17 Jul 2006 15:51:54 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Jing",
"Jietai",
""
],
[
"Feng",
"Sheng",
""
],
[
"Bloomer",
"Russell",
""
],
[
"Pfister",
"Olivier",
""
]
] |
quant-ph/0604135
|
Paul Benioff
|
Paul Benioff (Argonne National Laboratory, Argonne, IL)
|
Fields of Iterated Quantum Reference Frames based on Gauge
Transformations of Rational String States
|
15 pages, 4 figures
| null | null | null |
quant-ph gr-qc hep-th
| null |
This work is based on a description of quantum reference frames that seems
more basic than others in the literature. Here a frame is based on a set of
real and of complex numbers and a space time as a 4-tuple of the real numbers.
There are many isomorphic frames as there are many isomorphic sets of real
numbers. Each frame is suitable for construction of all physical theories as
mathematical structures over the real and complex numbers. The organization of
the frames into a field of frames is based on the representations of real and
complex numbers as Cauchy operators defined on complex rational states of
finite qubit strings. The structure of the field is based on noting that the
construction of real and complex numbers as Cauchy operators in a frame can be
iterated to create new frames coming from a frame. Gauge transformations on the
rational string states greatly expand the number of quantum frames as, for each
gauge U, there is one frame coming from the original frame. Forward and
backward iteration of the construction yields a two way infinite frame field
with satisfying properties. There is no background space time and there are no
real or complex numbers for the field as a whole. Instead these are relative
concepts associated with each frame in the field. Extension to include qukit
strings for different k bases, is described as is the problem of reconciling
the frame field to the existence of just one frame with one background space
time for the observable physical universe.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 20:38:43 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Benioff",
"Paul",
"",
"Argonne National Laboratory, Argonne, IL"
]
] |
quant-ph/0604136
|
Fernando M. Cucchietti
|
Fernando Martin Cucchietti, Sonia Fernandez-Vidal, and Juan Pablo Paz
|
Universal decoherence induced by an environmental quantum phase
transition
| null |
Phys. Rev. A 75, 032337 (2007)
|
10.1103/PhysRevA.75.032337
|
LA-UR-06-2517
|
quant-ph
| null |
Decoherence induced by coupling a system with an environment may display
universal features. Here we demostrate that when the coupling to the system
drives a quantum phase transition in the environment, the temporal decay of
quantum coherences in the system is Gaussian with a width independent of the
system-environment coupling strength. The existence of this effect opens the
way for a new type of quantum simulation algorithm, where a single qubit is
used to detect a quantum phase transition. We discuss possible implementations
of such algorithm and we relate our results to available data on universal
decoherence in NMR echo experiments.
|
[
{
"version": "v1",
"created": "Tue, 18 Apr 2006 21:05:30 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Cucchietti",
"Fernando Martin",
""
],
[
"Fernandez-Vidal",
"Sonia",
""
],
[
"Paz",
"Juan Pablo",
""
]
] |
quant-ph/0604137
|
Alastair Kay
|
A. Kay
|
State Transfer and Spin Measurement
|
4 pages, 2 figures
|
Phys. Rev. Lett. 98, 010501 (2007)
|
10.1103/PhysRevLett.98.010501
| null |
quant-ph
| null |
We present a Hamiltonian that can be used for amplifying the signal from a
quantum state, enabling the measurement of a macroscopic observable to
determine the state of a single spin. We prove a general mapping between this
Hamiltonian and an exchange Hamiltonian for arbitrary coupling strengths and
local magnetic fields. This facilitates the use of existing schemes for perfect
state transfer to give perfect amplification. We further prove a link between
the evolution of this fixed Hamiltonian and classical Cellular Automata,
thereby unifying previous approaches to this amplification task.
Finally, we show how to use the new Hamiltonian for perfect state transfer in
the, to date, unique scenario where total spin is not conserved during the
evolution, and demonstrate that this yields a significantly different response
in the presence of decoherence.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 05:30:43 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Apr 2006 01:41:54 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Kay",
"A.",
""
]
] |
quant-ph/0604138
|
Pradyumna Kumar Pathak
|
P. K. Pathak and G. S. Agarwal
|
Quantum random walk of two photons in separable and entangled state
| null |
Phys. Rev. A 75, 032351 (2007)
|
10.1103/PhysRevA.75.032351
| null |
quant-ph
| null |
We discuss quantum random walk of two photons using linear optical elements.
We analyze the quantum random walk using photons in a variety of quantum states
including entangled states. We find that for photons initially in separable
Fock states, the final state is entangled. For polarization entangled photons
produced by type II downconverter, we calculate the joint probability of
detecting two photons at a given site. We show the remarkable dependence of the
two photon detection probability on the quantum nature of the state. In order
to understand the quantum random walk, we present exact analytical results for
small number of steps like five. We present in details numerical results for a
number of cases and supplement the numerical results with asymptotic analytical
results.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 06:04:59 GMT"
},
{
"version": "v2",
"created": "Fri, 8 Sep 2006 06:53:09 GMT"
},
{
"version": "v3",
"created": "Wed, 8 Nov 2006 07:55:43 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Pathak",
"P. K.",
""
],
[
"Agarwal",
"G. S.",
""
]
] |
quant-ph/0604139
|
Pieter Kok
|
Pieter Kok
|
Creating large noon states with imperfect phase control
|
3 pages, 1 figure, more formal derivation of Heisenberg limit
| null | null | null |
quant-ph
| null |
Optical noon states (|N,0> + |0,N>) are an important resource for
Heisenberg-limited metrology and quantum lithography. The only known methods
for creating noon states with arbitrary $N$ via linear optics and projective
measurments seem to have a limited range of application due to imperfect phase
control. Here, we show that bootstrapping techniques can be used to create
high-fidelity noon states of arbitrary size.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 11:00:33 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Jul 2006 09:03:56 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Kok",
"Pieter",
""
]
] |
quant-ph/0604140
|
Peter Rabl
|
P. Rabl, D. DeMille, J. M. Doyle, M. D. Lukin, R. J. Schoelkopf, and
P. Zoller
|
Hybrid Quantum Processors: molecular ensembles as quantum memory for
solid state circuits
| null |
Phys. Rev. Lett. 97, 033003 (2006)
|
10.1103/PhysRevLett.97.033003
| null |
quant-ph cond-mat.supr-con
| null |
We investigate a hybrid quantum circuit where ensembles of cold polar
molecules serve as long-lived quantum memories and optical interfaces for solid
state quantum processors. The quantum memory realized by collective spin states
(ensemble qubit) is coupled to a high-Q stripline cavity via microwave Raman
processes. We show that for convenient trap-surface distances of a few $\mu$m,
strong coupling between the cavity and ensemble qubit can be achieved. We
discuss basic quantum information protocols, including a swap from the cavity
photon bus to the molecular quantum memory, and a deterministic two qubit gate.
Finally, we investigate coherence properties of molecular ensemble quantum
bits.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 13:09:19 GMT"
}
] | 2009-12-20T00:00:00 |
[
[
"Rabl",
"P.",
""
],
[
"DeMille",
"D.",
""
],
[
"Doyle",
"J. M.",
""
],
[
"Lukin",
"M. D.",
""
],
[
"Schoelkopf",
"R. J.",
""
],
[
"Zoller",
"P.",
""
]
] |
quant-ph/0604141
|
Falk Unger
|
Harry Buhrman, Richard Cleve, Monique Laurent, Noah Linden, Alexander
Schrijver, Falk Unger
|
New Limits on Fault-Tolerant Quantum Computation
|
references and typos corrected, 18 pages
| null | null | null |
quant-ph
| null |
We show that quantum circuits cannot be made fault-tolerant against a
depolarizing noise level of approximately 45%, thereby improving on a previous
bound of 50% (due to Razborov). Our precise quantum circuit model enables
perfect gates from the Clifford group (CNOT, Hadamard, S, X, Y, Z) and
arbitrary additional one-qubit gates that are subject to that much depolarizing
noise. We prove that this set of gates cannot be universal for arbitrary (even
classical) computation, from which the upper bound on the noise threshold for
fault-tolerant quantum computation follows.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 11:42:56 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Apr 2006 10:05:42 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Buhrman",
"Harry",
""
],
[
"Cleve",
"Richard",
""
],
[
"Laurent",
"Monique",
""
],
[
"Linden",
"Noah",
""
],
[
"Schrijver",
"Alexander",
""
],
[
"Unger",
"Falk",
""
]
] |
quant-ph/0604142
|
Hans-Thomas Elze
|
Hans-Thomas Elze
|
Gauge Symmetry of the Third Kind and Quantum Mechanics as an Infrared
Phenomenon
|
12 pages. To appear in the Festschrift "A Sense of Beauty in Physics"
dedicated to Adriano Di Giacomo on occasion of his 70th birthday
|
Sense of Beauty in Physics: A Volume in Honour of Adriano Di
Giacomo, edited by M. D'Elia, K. Konishi, E. Meggiolaro, P. Rossi (Edizioni
Plus, Pisa University Press, Pisa, 2006), 275-286
| null | null |
quant-ph
| null |
We introduce functional degrees of freedom by a new gauge principle related
to the phase of the wave functional. Thereby, quantum mechanical systems are
seen as dissipatively embedded part of a nonlinear classical structure
producing universal correlations. There are a fundamental length and an
entropy/area parameter, besides standard couplings. For states that are
sufficiently spread over configuration space, quantum field theory is
recovered.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 13:09:25 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Elze",
"Hans-Thomas",
""
]
] |
quant-ph/0604143
|
Ivo Degiovanni
|
E. Puddu, A. Andreoni, I. P. Degiovanni, M. Bondani, S. Castelletto
|
Ghost imaging with intense fields from chaotically-seeded parametric
downconversion
|
A slightly revised version will appear on OPT. LETT
| null |
10.1364/OL.32.001132
| null |
quant-ph
| null |
We present the first experimental demonstration of ghost imaging realized
with intense beams generated by a parametric downconversion interaction seeded
with pseudo-thermal light. As expected, the real image of the object is
reconstructed satisfying the thin-lens equation. We show that the experimental
visibility of the reconstructed image is in accordance with the theoretically
expected one.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 15:34:28 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Sep 2006 12:34:54 GMT"
},
{
"version": "v3",
"created": "Tue, 5 Dec 2006 15:31:29 GMT"
},
{
"version": "v4",
"created": "Tue, 13 Feb 2007 15:47:20 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Puddu",
"E.",
""
],
[
"Andreoni",
"A.",
""
],
[
"Degiovanni",
"I. P.",
""
],
[
"Bondani",
"M.",
""
],
[
"Castelletto",
"S.",
""
]
] |
quant-ph/0604144
|
Olivier Dulieu
|
Mireille Aymar (LAC), Olivier Dulieu (LAC), Fernand Spiegelman (LPQ)
|
Electronic properties of Francium diatomic compounds and prospects for
cold molecule formation
| null | null |
10.1088/0953-4075/39/19/S07
| null |
quant-ph physics.chem-ph
| null |
In this work we investigate the possibility to create cold Fr$\_2$, RbFr, and
CsFr molecules through photoassociation of cold atoms. Potential curves,
permanent and transition dipole moments for the Francium dimer and for the RbFr
and RbCs molecules are determined for the first time. The Francium atom is
modelled as a one valence electron moving in the field of the Fr$^+$ core,
which is described by a new pseudopotential with averaged relativistic effects,
and including effective core polarization potential. The molecular calculations
are performed for both the ionic species Fr$\_2^+$, RbFr$^+$, CsFr$^+$ and the
corresponding neutral, through the CIPSI quantum chemistry package where we
used new extended gaussian basis sets for Rb, Cs, and Fr atoms. As no
experimental data is available, we discuss our results by comparison with the
Rb$\_2$, Cs$\_2$, and RbCs systems. The dipole moment of CsFr reveals an
electron transfer yielding a Cs$^+$Fr$^-$ arrangement, while in all other mixed
alkali pairs the electron is transferred towards the lighter species. Finally
the perturbative treatment of the spin-orbit coupling at large distances
predicts that in contrast with Rb$\_2$ and Cs$\_2$, no double-well excited
potential should be present in Fr$\_2$, probably preventing an efficient
formation of cold dimers via photoassociation of cold Francium atoms.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 15:48:31 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Aymar",
"Mireille",
"",
"LAC"
],
[
"Dulieu",
"Olivier",
"",
"LAC"
],
[
"Spiegelman",
"Fernand",
"",
"LPQ"
]
] |
quant-ph/0604145
|
Michael Seevinck
|
J. Uffink and M. Seevinck
|
Strengthened Bell inequalities for orthogonal spin directions
|
v2: Considerably changed, many new and stronger results v3: Published
version; To appear in Physics Letters A. Online available from publishers
website
|
Physics Letters A, vol. 372, 1205 (2008)
|
10.1016/j.physleta.2007.09.033
| null |
quant-ph
| null |
We strengthen the bound on the correlations of two spin-1/2 particles
(qubits) in separable (non-entangled) states for locally orthogonal spin
directions by much tighter bounds than the well-known Bell inequality. This
provides a sharper criterion for the experimental distinction between entangled
and separable states, and even one which is a necessary and sufficient
condition for separability. However, these improved bounds do not apply to
local hidden-variable theories, and hence they provide a criterion to test the
correlations allowed by local hidden-variable theories against those allowed by
separable quantum states. Furthermore, these bounds are stronger than some
recent alternative experimentally accessible entanglement criteria. We also
address the issue of finding a finite subset of these inequalities that would
already form a necessary and sufficient condition for non-entanglement. For
mixed state we have not been able to resolve this, but for pure states a set of
six inequalities using only three sets of orthogonal observables is shown to be
already necessary and sufficient for separability.
|
[
{
"version": "v1",
"created": "Wed, 19 Apr 2006 16:46:29 GMT"
},
{
"version": "v2",
"created": "Sat, 7 Jul 2007 17:35:54 GMT"
},
{
"version": "v3",
"created": "Wed, 28 Nov 2007 19:29:48 GMT"
}
] | 2008-02-22T00:00:00 |
[
[
"Uffink",
"J.",
""
],
[
"Seevinck",
"M.",
""
]
] |
quant-ph/0604146
|
Yibo Zhao
|
Yibo Zhao
|
Generalized Continuous Variables Quantum Key Distribution
| null | null | null | null |
quant-ph
| null |
This paper has been withdrawn by the author due to the incorrect argument for
the security.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 09:32:05 GMT"
},
{
"version": "v2",
"created": "Wed, 11 Oct 2006 08:53:55 GMT"
},
{
"version": "v3",
"created": "Mon, 26 May 2008 11:10:29 GMT"
}
] | 2008-05-26T00:00:00 |
[
[
"Zhao",
"Yibo",
""
]
] |
quant-ph/0604147
|
Dafa Li
|
D. Li, H. Huang, X. Li
|
The Necessary and Sufficient Conditions of Separability for Multipartite
Pure States
|
Submitted to PRL in Sep. 2004, the paper No is LV9637. Submitted to
SIAM on computing, in Jan., 2005, the paper No. is SICOMP 44687. Under
reviewing now
|
Commun. Theor. Phys. 49, 1211-1216 (2008)
|
10.1088/0253-6102/49/5/29
| null |
quant-ph
| null |
In this paper we present the necessary and sufficient conditions of
separability for multipartite pure states. These conditions are very simple,
and they don't require Schmidt decomposition or tracing out operations. We also
give a necessary condition for a local unitary equivalence class for a
bipartite system in terms of the determinant of the matrix of amplitudes and
explore a variance as a measure of entanglement for multipartite pure states.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 08:37:54 GMT"
}
] | 2012-05-08T00:00:00 |
[
[
"Li",
"D.",
""
],
[
"Huang",
"H.",
""
],
[
"Li",
"X.",
""
]
] |
quant-ph/0604148
|
Franco Ventriglia
|
V.I. Man'ko, G. Marmo, A. Simoni, E.C.G. Sudarshan, F. Ventriglia
|
A tomographic setting for quasi-distribution functions
|
A slightly enlarged version in which contact with the Agarwal-Wolf
$\Omega$-operator ordering theory is made
|
Rept.Math.Phys.61:337-359,2008
|
10.1016/S0034-4877(08)00016-5
| null |
quant-ph hep-th math-ph math.MP
| null |
The method of constructing the tomographic probability distributions
describing quantum states in parallel with density operators is presented.
Known examples of Husimi-Kano quasi-distribution and photon number tomography
are reconsidered in the new setting. New tomographic schemes based on coherent
states and nonlinear coherent states of deformed oscillators, including
q-oscillators, are suggested. The associated identity decompositions providing
Gram-Schmidt operators are explicitly given, and contact with the Agarwal-Wolf
$\Omega$-operator ordering theory is made.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 09:16:34 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 14:10:21 GMT"
}
] | 2009-02-23T00:00:00 |
[
[
"Man'ko",
"V. I.",
""
],
[
"Marmo",
"G.",
""
],
[
"Simoni",
"A.",
""
],
[
"Sudarshan",
"E. C. G.",
""
],
[
"Ventriglia",
"F.",
""
]
] |
quant-ph/0604149
|
Yuan Feng
|
Yuan Feng, Runyao Duan, Zhengfeng Ji
|
Optimal dense coding with arbitrary pure entangled states
|
5 pages, journal version
|
Phys. Rev. A 74, 012310 (2006)
|
10.1103/PhysRevA.74.012310
| null |
quant-ph
| null |
We examine dense coding with an arbitrary pure entangled state sharing
between the sender and the receiver. Upper bounds on the average success
probability in approximate dense coding and on the probability of conclusive
results in unambiguous dense coding are derived. We also construct the optimal
protocol which saturates the upper bound in each case.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 11:45:43 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Aug 2006 00:32:59 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Feng",
"Yuan",
""
],
[
"Duan",
"Runyao",
""
],
[
"Ji",
"Zhengfeng",
""
]
] |
quant-ph/0604150
|
Yair Goldfarb
|
Yair Goldfarb, Ilan Degani and David J. Tannor
|
Bohmian Mechanics with Complex Action: A New Trajectory-Based
Formulation of Quantum Mechanics
| null | null |
10.1063/1.2798762
| null |
quant-ph
| null |
In recent years there has been a resurgence of interest in Bohmian mechanics
as a numerical tool because of its local dynamics, which suggest the
possibility of significant computational advantages for the simulation of large
quantum systems. However, closer inspection of the Bohmian formulation reveals
that the nonlocality of quantum mechanics has not disappeared -- it has simply
been swept under the rug into the quantum force. In this paper we present a new
formulation of Bohmian mechanics in which the quantum action, S, is taken to be
complex. This leads to a single equation for complex S, and ultimately complex
x and p but there is a reward for this complexification -- a significantly
higher degree of localization. The quantum force in the new approach vanishes
for Gaussian wavepacket dynamics, and its effect on barrier tunneling processes
is orders of magnitude lower than that of the classical force. We demonstrate
tunneling probabilities that are in virtually perfect agreement with the exact
quantum mechanics down to 10^{-7} calculated from strictly localized quantum
trajectories that do not communicate with their neighbors. The new formulation
may have significant implications for fundamental quantum mechanics, ranging
from the interpretation of non-locality to measures of quantum complexity.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 13:03:43 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Goldfarb",
"Yair",
""
],
[
"Degani",
"Ilan",
""
],
[
"Tannor",
"David J.",
""
]
] |
quant-ph/0604151
|
Gennady Sardanashvily
|
G.Giachetta, L.Mangiarotti, G.Sardanashvily
|
Quantization of noncommutative completely integrable Hamiltonian systems
|
11 pages, accepted for publication in Phys. Lett. A
|
Physics Letters A, v.362 (2007) 138-142
|
10.1016/j.physleta.2006.10.011
| null |
quant-ph math-ph math.MP
| null |
Integrals of motion of a Hamiltonian system need not be commutative. The
classical Mishchenko-Fomenko theorem enables one to quantize a noncommutative
completely integrable Hamiltonian system around its invariant submanifold as an
abelian completely integrable Hamiltonian system.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 13:11:54 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Oct 2006 17:17:08 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Giachetta",
"G.",
""
],
[
"Mangiarotti",
"L.",
""
],
[
"Sardanashvily",
"G.",
""
]
] |
quant-ph/0604152
|
Petr Marek
|
P. Marek, M. S. Kim, and M. Paternostro
|
Characterization of the entanglement of two squeezed states
|
Minor changes, journal reference added
|
Phys. Rev. A 74, 032311 (2006)
|
10.1103/PhysRevA.74.032311
| null |
quant-ph
| null |
We study a continuous-variable entangled state composed of two states which
are squeezed in two opposite quadratures in phase space. Various entanglement
conditions are tested for the entangled squeezed state and we study decoherence
models for noise, producing a mixed entangled squeezed state. We briefly
describe a probabilistic protocol for entanglement swapping based on the use of
this class of entangled states and the main features of a general generation
scheme.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 13:16:29 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Sep 2006 16:53:16 GMT"
}
] | 2010-08-05T00:00:00 |
[
[
"Marek",
"P.",
""
],
[
"Kim",
"M. S.",
""
],
[
"Paternostro",
"M.",
""
]
] |
quant-ph/0604153
|
Robert Johnson
|
Robert W. Johnson
|
Quantum Mechanics associated with a Finite Group
|
Submitted to Intern. J. Theor. Phys
| null | null | null |
quant-ph
| null |
I describe, in the simplified context of finite groups and their
representations, a mathematical model for a physical system that contains both
its quantum and classical aspects. The physically observable system is
associated with the space containing elements fxf for f an element in the
regular representation of a given finite group G. The Hermitian portion of fxf
is the Wigner distribution of f whose convolution with a test function leads to
a mathematical description of the quantum measurement process. Starting with
the Jacobi group that is formed from the semidirect product of the Heisenberg
group with its automorphism group SL(2,F{N}) for N an odd prime number I show
that the classical phase space is the first order term in a series of subspaces
of the Hermitian portion of fxf that are stable under SL(2,F{N}). I define a
derivative that is analogous to a pseudodifferential operator to enable a
treatment that parallels the continuum case. I give a new derivation of the
Schrodinger-Weil representation of the Jacobi group. Keywords: quantum
mechanics, finite group, metaplectic. PACS: 03.65.Fd; 02.10.De; 03.65.Ta.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 16:03:09 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Johnson",
"Robert W.",
""
]
] |
quant-ph/0604154
|
Leble Sergey
|
Sergey Leble, Artem Yurov
|
Initial problem for heat equation with multisoliton inhomogeneity and
one-loop quantum corrections
|
5 pages, annual conference of Immanuele Kant State University (former
Kaliningrad State University) in 1993
| null | null | null |
quant-ph
| null |
The generalized zeta-function is built by a dressing method based on the
Darboux covariance of the heat equation and used to evaluate the correspondent
functional integral in quasiclassical approximation. Quantum corrections to a
kink-like solutions of Landau-Ginzburg model are calculated.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 16:42:05 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Leble",
"Sergey",
""
],
[
"Yurov",
"Artem",
""
]
] |
quant-ph/0604155
|
Alberto Montina
|
Alberto Montina
|
A condition for any realistic theory of quantum systems
| null |
Phys. Rev. Lett. 97, 180401 (2006)
|
10.1103/PhysRevLett.97.180401
| null |
quant-ph
| null |
In quantum physics, the density operator completely describes the state.
Instead, in classical physics the mean value of every physical quantity is
evaluated by means of a probability distribution. We study the possibility to
describe pure quantum states and events with classical probability
distributions and conditional probabilities and prove that the distributions
can not be quadratic functions of the quantum state. Some examples are
considered. Finally, we deal with the exponential complexity problem of quantum
physics and introduce the concept of classical dimension for a quantum system.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 19:14:34 GMT"
},
{
"version": "v2",
"created": "Sat, 15 Dec 2007 00:46:13 GMT"
}
] | 2011-11-09T00:00:00 |
[
[
"Montina",
"Alberto",
""
]
] |
quant-ph/0604156
|
Wesley B. Cardoso
|
W. B. Cardoso, A.T. Avelar, B. Baseia, and N.G. de Almeida
|
Teleportation of entangled states without Bell-state measurement
|
4 pages, 1 figure, published in Phys. Rev. A 72, 045802 (2005)
|
Phys. Rev. A 72, 045802 (2005)
|
10.1103/PhysRevA.72.045802
| null |
quant-ph
| null |
In a recent paper [Phys. Rev. A 70, 025803 (2004)] we presented a scheme to
teleport an entanglement of zero- and one-photon states from a bimodal cavity
to another one, with 100% success probability. Here, inspired on recent results
in the literature, we have modified our previous proposal to teleport the same
entangled state without using Bell-state measurements. For comparison, the time
spent, the fidelity, and the success probability for this teleportation are
considered.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 19:58:50 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Cardoso",
"W. B.",
""
],
[
"Avelar",
"A. T.",
""
],
[
"Baseia",
"B.",
""
],
[
"de Almeida",
"N. G.",
""
]
] |
quant-ph/0604157
|
Tamas Geszti
|
J\'ozsef Zsolt Bern\'ad, Lajos Di\'osi, and Tam\'as Geszti
|
Quest for quantum superpositions of a mirror: high and moderately low
temperatures
|
revised; the published version
|
Phys. Rev. Lett. {\bf 97,} 250404 (2006)
|
10.1103/PhysRevLett.97.250404
| null |
quant-ph
| null |
The Born-Markov master equation analysis of the vibrating mirror and photon
experiment proposed by Marshall, Simon, Penrose and Bouwmeester is completed by
including the important issues of temperature and friction. We find that at the
level of cooling available to date, visibility revivals are purely classical,
and no quantum effect can be detected by the setup, no matter how strong the
photon-mirror coupling is. Checking proposals of universal nonenvironmental
decoherence is ruled out by dominating thermal decoherence; a conjectured
coordinate-diffusion contribution to decoherence may become observable on
reaching moderately low temperatures.
|
[
{
"version": "v1",
"created": "Thu, 20 Apr 2006 20:14:07 GMT"
},
{
"version": "v2",
"created": "Sat, 23 Dec 2006 17:01:34 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Bernád",
"József Zsolt",
""
],
[
"Diósi",
"Lajos",
""
],
[
"Geszti",
"Tamás",
""
]
] |
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