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2025-04-04 00:00:00
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/0605242
|
Hao Fu
|
Hao Fu, P. R. Berman
|
Microscopic Theory of the Photon Recoil of an Atom in a Dielectric
|
15 pages, 2 figures. Several typos and one reference are corrected
| null | null | null |
quant-ph
| null |
An atom recoils when it undergoes spontaneous decay. In this paper we present
a microscopic calculation of the recoil of a source atom imbedded in a
dielectric medium. We find that the source atom recoils with the canonical
photon momentum $n\hbar k_{0,}$ where $n$ is the index of refraction and $\hbar
k_{0}$ is the photon momentum calculated at the source atom atomic frequency
$\omega_{0}$. We also show explicitly how the energy is conserved with the
photon inside the medium.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 13:44:41 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Oct 2006 20:12:40 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Fu",
"Hao",
""
],
[
"Berman",
"P. R.",
""
]
] |
quant-ph/0605243
|
Jeffrey Bub
|
Jeffrey Bub
|
Quantum computation from a quantum logical perspective
|
17 pages, no figures. The title has been changed, misprints and minor
errors have been corrected, and some clarifying remarks have been added
| null | null | null |
quant-ph
| null |
It is well-known that Shor's factorization algorithm, Simon's period-finding
algorithm, and Deutsch's original XOR algorithm can all be formulated as
solutions to a hidden subgroup problem. Here the salient features of the
information-processing in the three algorithms are presented from a different
perspective, in terms of the way in which the algorithms exploit the
non-Boolean quantum logic represented by the projective geometry of Hilbert
space. From this quantum logical perspective, the XOR algorithm appears
directly as a special case of Simon's algorithm, and all three algorithms can
be seen as exploiting the non-Boolean logic represented by the subspace
structure of Hilbert space in a similar way. Essentially, a global property of
a function (such as a period, or a disjunctive property) is encoded as a
subspace in Hilbert space representing a quantum proposition, which can then be
efficiently distinguished from alternative propositions, corresponding to
alternative global properties, by a measurement (or sequence of measurements)
that identifies the target proposition as the proposition represented by the
subspace containing the final state produced by the algorithm.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 15:27:07 GMT"
},
{
"version": "v2",
"created": "Sat, 28 Oct 2006 22:39:26 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Bub",
"Jeffrey",
""
]
] |
quant-ph/0605244
|
Michael Garrett
|
Michael C. Garrett and David L. Feder
|
Perfect Cluster States from Imperfect Global Entanglement
|
16 pages IOP style, 4 EPS figures; major revisions to the strategy
for growth of cluster states, 2 new figures, several new references; accepted
for publication in NJP
|
New J. Phys. 10 (2008) 033009
|
10.1088/1367-2630/10/3/033009
| null |
quant-ph cond-mat.other
| null |
The cluster state, the highly entangled state that is the central resource
for one-way quantum computing, can be efficiently generated in a variety of
physical implementations via global nearest-neighbor interactions. In practice,
a systematic phase error is expected in the entangling process, resulting in
imperfect cluster states. We present a stochastic measurement technique to
generate large perfect cluster states and other graph states with high
probability from imperfect cluster states even when their initial entanglement
is weak.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 16:27:04 GMT"
},
{
"version": "v2",
"created": "Fri, 22 Jun 2007 17:34:16 GMT"
},
{
"version": "v3",
"created": "Wed, 13 Feb 2008 23:19:15 GMT"
}
] | 2008-03-10T00:00:00 |
[
[
"Garrett",
"Michael C.",
""
],
[
"Feder",
"David L.",
""
]
] |
quant-ph/0605245
|
Chuanwei Zhang
|
Chuanwei Zhang, S. L. Rolston, and S. Das Sarma
|
Manipulation of Single Neutral Atoms in Optical Lattices
|
5 pages, 3 figures
|
Phys. Rev. A. 74, 042316 (2006)
|
10.1103/PhysRevA.74.042316
| null |
quant-ph cond-mat.soft
| null |
We analyze a scheme to manipulate quantum states of neutral atoms at
individual sites of optical lattices using focused laser beams. Spatial
distributions of focused laser intensities induce position-dependent energy
shifts of hyperfine states, which, combined with microwave radiation, allow
selective manipulation of quantum states of individual target atoms. We show
that various errors in the manipulation process are suppressed below $10^{-4} $
with properly chosen microwave pulse sequences and laser parameters. A similar
idea is also applied to measure quantum states of single atoms in optical
lattices.
|
[
{
"version": "v1",
"created": "Mon, 29 May 2006 17:46:19 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Jul 2006 13:57:35 GMT"
},
{
"version": "v3",
"created": "Wed, 25 Oct 2006 14:07:57 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Zhang",
"Chuanwei",
""
],
[
"Rolston",
"S. L.",
""
],
[
"Sarma",
"S. Das",
""
]
] |
quant-ph/0605246
|
Stefano Pironio
|
Antonio Acin, Serge Massar, Stefano Pironio
|
Efficient quantum key distribution secure against no-signalling
eavesdroppers
|
11 pages, 2 color figures. v2: minor modifications, added references,
added note on the relation to quant-ph/0606049
|
New J. Phys. 8, 126 (2006)
|
10.1088/1367-2630/8/8/126
| null |
quant-ph
| null |
By carrying out measurements on entangled states, two parties can generate a
secret key which is secure not only against an eavesdropper bound by the laws
of quantum mechanics, but also against a hypothetical "post-quantum"
eavesdroppers limited by the no-signalling principle only. We introduce a
family of quantum key distribution protocols of this type, which are more
efficient than previous ones, both in terms of key rate and noise resistance.
Interestingly, the best protocols involve large number of measurements. We show
that in the absence of noise, these protocols can yield one secret bit per
entanglement bit, implying that the key rates in the no-signalling post-quantum
scenario are comparable to the key rates in usual quantum key distribution.
|
[
{
"version": "v1",
"created": "Tue, 30 May 2006 08:15:58 GMT"
},
{
"version": "v2",
"created": "Thu, 3 Aug 2006 11:40:10 GMT"
}
] | 2007-10-22T00:00:00 |
[
[
"Acin",
"Antonio",
""
],
[
"Massar",
"Serge",
""
],
[
"Pironio",
"Stefano",
""
]
] |
quant-ph/0605247
|
Austin Lund
|
A. P. Lund, T. C. Ralph and P. van Loock
|
Non-Gaussian, Mixed Continuous-Variable Entangled States
| null | null | null | null |
quant-ph
| null |
We study a class of mixed non-Gaussian entangled states that, whilst closely
related to Gaussian entangled states, none-the-less exhibit distinct properties
previously only associated with more exotic, pure non-Gaussian states.
|
[
{
"version": "v1",
"created": "Tue, 30 May 2006 15:43:08 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Lund",
"A. P.",
""
],
[
"Ralph",
"T. C.",
""
],
[
"van Loock",
"P.",
""
]
] |
quant-ph/0605248
|
Diego Dalvit
|
D.A.R. Dalvit, F.D. Mazzitelli, and X. Orsi Millan
|
Dynamical Casimir effect for different geometries
|
12 pages, 3 figures, J. Phys. A Special Issue: Proceedings of QEFTX,
Barcelona 5-9 Sept. 2005
|
J. Phys. A: Math. Gen. 39 (2006) 6261-6270
|
10.1088/0305-4470/39/21/S17
| null |
quant-ph
| null |
We consider the problem of motion-induced photon creation from quantum vacuum
inside closed, perfectly conducting cavities with time-dependent geometries.
These include one dimensional Fabry-Perrot resonators with Dirichlet or Neumann
boundary conditions, three dimensional cylindrical waveguides, and a spherical
shell. The number of Casimir TE, TM and TEM photons is computed. We also
present a classical mechanical analogue of the one dimensional dynamical
Casimir effect.
|
[
{
"version": "v1",
"created": "Tue, 30 May 2006 19:56:12 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Dalvit",
"D. A. R.",
""
],
[
"Mazzitelli",
"F. D.",
""
],
[
"Millan",
"X. Orsi",
""
]
] |
quant-ph/0605249
|
Maximilian Schlosshauer
|
Maximilian Schlosshauer
|
Classicality, the ensemble interpretation, and decoherence: Resolving
the Hyperion dispute
|
5 pages, final published version
|
Found. Phys. 38, 796-803 (2008)
|
10.1007/s10701-008-9237-x
| null |
quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyze seemingly contradictory claims in the literature about the role
played by decoherence in ensuring classical behavior for the chaotically
tumbling satellite Hyperion. We show that the controversy is resolved once the
very different assumptions underlying these claims are recognized. In doing so,
we emphasize the distinct notions of the problem of classicality in the
ensemble interpretation of quantum mechanics and in decoherence-based
approaches that are aimed at addressing the measurement problem.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 00:32:06 GMT"
},
{
"version": "v2",
"created": "Thu, 24 Aug 2006 05:35:55 GMT"
},
{
"version": "v3",
"created": "Tue, 29 Jan 2008 23:25:21 GMT"
},
{
"version": "v4",
"created": "Tue, 30 Sep 2008 07:15:41 GMT"
}
] | 2008-09-30T00:00:00 |
[
[
"Schlosshauer",
"Maximilian",
""
]
] |
quant-ph/0605250
|
Florian Mintert
|
Florian Mintert, Andreas Buchleitner
|
An observable entanglement measure for unknown mixed quantum states
|
in press in PRL
| null |
10.1103/PhysRevLett.98.140505
| null |
quant-ph
| null |
We show how an unknown mixed quantum state's entanglement can be quantified
by a suitable, local parity measurement on its two-fold copy.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 02:41:11 GMT"
},
{
"version": "v2",
"created": "Mon, 4 Sep 2006 19:10:38 GMT"
},
{
"version": "v3",
"created": "Fri, 23 Feb 2007 23:51:44 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Mintert",
"Florian",
""
],
[
"Buchleitner",
"Andreas",
""
]
] |
quant-ph/0605251
|
Valerio Cappellini Dr.
|
Valerio Cappellini (1), Hans-Juergen Sommers (2) and Karol Zyczkowski
(1 and 3) ((1) Centrum Fizyki Teoretycznej, Polska Akademia Nauk, Warszawa,
Poland, (2) Fachbereich Physik, Universitat Duisburg-Essen, Campus Duisburg,
Duisburg, Germany, (3) Instytut Fizyki im. Smoluchowskiego, Uniwersytet
Jagiellonski, Krakow, Poland)
|
Distribution of G-concurrence of random pure states
|
RevTeX4, 11 pages, 4 Encapsuled PostScript figures - Introduced new
results, Section II and V have been significantly improved - To appear on PRA
|
Phys. Rev. A 74(6), 062322 (2006)
|
10.1103/PhysRevA.74.062322
| null |
quant-ph math-ph math.MP
| null |
Average entanglement of random pure states of an N x N composite system is
analyzed. We compute the average value of the determinant D of the reduced
state, which forms an entanglement monotone. Calculating higher moments of the
determinant we characterize the probability distribution P(D). Similar results
are obtained for the rescaled N-th root of the determinant, called
G-concurrence. We show that in the limit $N\to\infty$ this quantity becomes
concentrated at a single point G=1/e. The position of the concentration point
changes if one consider an arbitrary N x K bipartite system, in the joint limit
$N,K\to\infty$, K/N fixed.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 16:26:33 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Nov 2006 14:11:13 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Cappellini",
"Valerio",
"",
"1 and 3"
],
[
"Sommers",
"Hans-Juergen",
"",
"1 and 3"
],
[
"Zyczkowski",
"Karol",
"",
"1 and 3"
]
] |
quant-ph/0605252
|
Evgeny Shapiro
|
Evgeny A. Shapiro, Moshe Shapiro, Avi Pe'er, and Jun Ye
|
Photoassociation adiabatic passage of ultracold Rb atoms to form
ultracold Rb_2 molecules
|
RevTex, 23 pages, 9 figures
|
Phys. Rev. A 75, 013405 (2007)
|
10.1103/PhysRevA.75.013405
| null |
quant-ph
| null |
We theoretically explore photoassociation by Adiabatic Passage of two
colliding cold ^{85}Rb atoms in an atomic trap to form an ultracold Rb_2
molecule. We consider the incoherent thermal nature of the scattering process
in a trap and show that coherent manipulations of the atomic ensemble, such as
adiabatic passage, are feasible if performed within the coherence time window
dictated by the temperature, which is relatively long for cold atoms. We show
that a sequence of ~2*10^7 pulses of moderate intensities, each lasting ~750
ns, can photoassociate a large fraction of the atomic ensemble at temperature
of 100 microkelvin and density of 10^{11} atoms/cm^3. Use of multiple pulse
sequences makes it possible to populate the ground vibrational state. Employing
spontaneous decay from a selected excited state, one can accumulate the
molecules in a narrow distribution of vibrational states in the ground
electronic potential. Alternatively, by removing the created molecules from the
beam path between pulse sets, one can create a low-density ensemble of
molecules in their ground ro-vibrational state.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 19:07:32 GMT"
},
{
"version": "v2",
"created": "Tue, 29 Aug 2006 22:38:09 GMT"
},
{
"version": "v3",
"created": "Tue, 17 Oct 2006 20:39:02 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Shapiro",
"Evgeny A.",
""
],
[
"Shapiro",
"Moshe",
""
],
[
"Pe'er",
"Avi",
""
],
[
"Ye",
"Jun",
""
]
] |
quant-ph/0605253
|
David P. Rideout
|
Matthew Barnett, Fay Dowker and David Rideout
|
Popescu-Rohrlich Boxes in Quantum Measure Theory
|
10 pages, 1 figure, LaTeX, acknowledgement added; Dedicated to Rafael
Sorkin on the occasion of his 60th birthday
|
J. Phys. A: Math. Theor. 40 (2007) 7255-7264
|
10.1088/1751-8113/40/26/011
|
Imperial/TP/2006/DR/01
|
quant-ph
| null |
Two results are proved at the quantal level in Sorkin's hierarchy of measure
theories. One is a strengthening of an existing bound on the correlations in
the EPR-Bohm setup under the assumption that the probabilities admit a strongly
positive joint quantal measure. It is also proved that any set of no-signalling
probabilities, for two distant experimenters with a choice of two alternative
experiments each and two possible outcomes per experiment, admits a joint
quantal measure, though one that is not necessarily strongly positive.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 16:56:55 GMT"
},
{
"version": "v2",
"created": "Thu, 1 Jun 2006 19:43:26 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Barnett",
"Matthew",
""
],
[
"Dowker",
"Fay",
""
],
[
"Rideout",
"David",
""
]
] |
quant-ph/0605254
|
Luis Roa Oppliger
|
A. Krugel, L. Roa, and C. Saavedra
|
Quantum state stability against decoherence
| null | null | null | null |
quant-ph
| null |
We study the stability of the coherence of a state of a quantum system under
the effect of an interaction with another quantum system at short time. We find
an expression for evaluating the order of magnitude of the time scale for the
onset of instability as a function of the initial state of both involved
systems and of the sort of interaction between them. As an application we study
the spin-boson interaction in the dispersive interaction regime, driven by a
classical field. We find, for this model, that the behavior of the time scale
for the onset of instability, with respect to the boson bath temperature,
changes depending on the intensity of the classical field.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 17:09:40 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Krugel",
"A.",
""
],
[
"Roa",
"L.",
""
],
[
"Saavedra",
"C.",
""
]
] |
quant-ph/0606001
|
Shengchao Ding
|
Shengchao Ding
|
Comment on "Quantum Strategy Without Entanglement"
|
1.3 pages, 2 figures; minor mistakes corrected
| null | null | null |
quant-ph
| null |
We make remarks on the paper of Du et al (quant-ph/0011078) by pointing out
that the quantum strategy proposed by the paper is trivial to the card game and
proposing a simple classical strategy to make the game in classical sense fair
too.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 03:52:07 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Sep 2006 05:30:27 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Ding",
"Shengchao",
""
]
] |
quant-ph/0606002
|
Cosmo Lupo
|
Paolo Aniello, Cosmo Lupo, Mario Napolitano, and Matteo G.A. Paris
|
Engineering multiphoton states for linear optics computation
| null |
Eur.Phys.J. D41 (2007) 579-587
|
10.1140/epjd/e2006-00259-y
| null |
quant-ph
| null |
Transformations achievable by linear optical components allow to generate the
whole unitary group only when restricted to the one-photon subspace of a
multimode Fock space. In this paper, we address the more general problem of
encoding quantum information by multiphoton states, and elaborating it via
ancillary extensions, linear optical passive devices and photodetection. Our
scheme stems in a natural way from the mathematical structures underlying the
physics of linear optical passive devices. In particular, we analyze an
economical procedure for mapping a fiducial 2-photon 2-mode state into an
arbitrary 2-photon 2-mode state using ancillary resources and linear optical
passive N-ports assisted by post-selection. We found that adding a single
ancilla mode is enough to generate any desired target state. The effect of
imperfect photodetection in post-selection is considered and a simple trade-off
between success probability and fidelity is derived.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 20:46:00 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Aniello",
"Paolo",
""
],
[
"Lupo",
"Cosmo",
""
],
[
"Napolitano",
"Mario",
""
],
[
"Paris",
"Matteo G. A.",
""
]
] |
quant-ph/0606003
|
Daniel Braun
|
Daniel Braun
|
Indirect decoherence in optical lattices and cold gases
|
12 pages, 1 figure
|
Eur. Phys. J D 42, 103 (2007)
|
10.1140/epjd/e2006-00272-2
| null |
quant-ph
| null |
The interaction of two--level atoms with a common heat bath leads to an
effective interaction between the atoms, such that with time the internal
degrees of the atoms become correlated or even entangled. If part of the atoms
remain unobserved this creates additional indirect decoherence for the selected
atoms, on top of the direct decoherence due to the interaction with the heat
bath. I show that indirect decoherence can drastically increase and even
dominate the decoherence for sufficiently large times. I investigate indirect
decoherence through thermal black body radiation quantitatively for atoms
trapped at regular positions in an optical lattice as well as for atoms at
random positions in a cold gas, and show how indirect coherence can be
controlled or even suppressed through experimentally accessible parameters.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 21:13:06 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Braun",
"Daniel",
""
]
] |
quant-ph/0606004
|
Enrique Solano
|
M. Franca Santos, G. Giedke, and E. Solano
|
Noise-Free Measurement of Harmonic Oscillators with Instantaneous
Interactions
|
4 pages, no figure, published in Physical Review Letters
|
Phys. Rev. Lett. 98, 020401 (2007)
|
10.1103/PhysRevLett.98.020401
| null |
quant-ph
| null |
We present a method of measuring the quantum state of a harmonic oscillator
through instantaneous probe-system selective interactions of the
Jaynes-Cummings type. We prove that this scheme is robust to general
decoherence mechanisms, allowing the possibility of measuring fast-decaying
systems in the weak-coupling regime. This method could be applied to different
setups: motional states of trapped ions, microwave fields in cavity/circuit
QED, and even intra-cavity optical fields.
|
[
{
"version": "v1",
"created": "Wed, 31 May 2006 22:07:40 GMT"
},
{
"version": "v2",
"created": "Mon, 8 Jan 2007 18:27:36 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Santos",
"M. Franca",
""
],
[
"Giedke",
"G.",
""
],
[
"Solano",
"E.",
""
]
] |
quant-ph/0606005
|
Yong Zhang
|
Yong Zhang (Chern Inst. Math.), Louis H. Kauffman (Illinois U.
Chicago) and Reinhard F. Werner (TU. Braunschweig)
|
Permutation and Its Partial Transpose
|
42 pages, 22 figures, latex
|
Int.J.Quant.Inf.5:469-507,2007
| null | null |
quant-ph hep-th math-ph math.MP
| null |
Permutation and its partial transpose play important roles in quantum
information theory. The Werner state is recognized as a rational solution of
the Yang--Baxter equation, and the isotropic state with an adjustable parameter
is found to form a braid representation. The set of permutation's partial
transposes is an algebra called the "PPT" algebra which guides the construction
of multipartite symmetric states. The virtual knot theory having permutation as
a virtual crossing provides a topological language describing quantum
computation having permutation as a swap gate. In this paper, permutation's
partial transpose is identified with an idempotent of the Temperley--Lieb
algebra. The algebra generated by permutation and its partial transpose is
found to be the Brauer algebra. The linear combinations of identity,
permutation and its partial transpose can form various projectors describing
tangles; braid representations; virtual braid representations underlying common
solutions of the braid relation and Yang--Baxter equations; and virtual
Temperley--Lieb algebra which is articulated from the graphical viewpoint. They
lead to our drawing a picture called the "ABPK" diagram describing knot theory
in terms of its corresponding algebra, braid group and polynomial invariant.
The paper also identifies nontrivial unitary braid representations with
universal quantum gates, and derives a Hamiltonian to determine the evolution
of a universal quantum gate, and further computes the Markov trace in terms of
a universal quantum gate for a link invariant to detect linking numbers.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 02:51:54 GMT"
}
] | 2008-11-26T00:00:00 |
[
[
"Zhang",
"Yong",
"",
"Chern Inst. Math."
],
[
"Kauffman",
"Louis H.",
"",
"Illinois U.\n Chicago"
],
[
"Werner",
"Reinhard F.",
"",
"TU. Braunschweig"
]
] |
quant-ph/0606006
|
Alberto Ventura
|
Francesco Cannata and Alberto Ventura
|
Scattering by PT-symmetric non-local potentials
|
11 pages
|
Czech. J. Phys. 56, 943 (2006)
|
10.1007/s10582-006-0390-1
| null |
quant-ph
| null |
A general formalism is worked out for the description of one-dimensional
scattering by non-local separable potentials and constraints on transmission
and reflection coefficients are derived in the cases of P, T, or PT invariance
of the Hamiltonian. The case of a solvable Yamaguchi potential is discussed in
detail.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 05:52:15 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Cannata",
"Francesco",
""
],
[
"Ventura",
"Alberto",
""
]
] |
quant-ph/0606007
|
Fu-Guo Deng
|
Xi-Han Li, Fu-Guo Deng, Chun-Yan Li, Yu-Jie Liang, Ping Zhou and
Hong-Yu Zhou
|
Deterministic secure quantum communication without maximally entangled
states
|
6 pages, no figure
|
Journal of the Korean Physical Society 49 (2006) 1354-1359
| null | null |
quant-ph
| null |
Two deterministic secure quantum communication schemes are proposed, one
based on pure entangled states and the other on $d$-dimensional single-photon
states. In these two schemes, only single-photon measurements are required for
the two authorized users, which makes the schemes more convenient than others
in practical applications. Although each qubit can be read out after a
transmission of additional classical bit, it is unnecessary for the users to
transmit qubits double the distance between the sender and the receiver, which
will increase their bit rate and their security. The parties use decoy photons
to check eavesdropping efficiently. The obvious advantage in the first scheme
is that the pure entangled source is feasible with present techniques.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 07:27:55 GMT"
},
{
"version": "v2",
"created": "Wed, 16 Aug 2006 08:35:49 GMT"
},
{
"version": "v3",
"created": "Mon, 16 Oct 2006 14:53:32 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Li",
"Xi-Han",
""
],
[
"Deng",
"Fu-Guo",
""
],
[
"Li",
"Chun-Yan",
""
],
[
"Liang",
"Yu-Jie",
""
],
[
"Zhou",
"Ping",
""
],
[
"Zhou",
"Hong-Yu",
""
]
] |
quant-ph/0606008
|
Fu-Guo Deng
|
Fu-Guo Deng, Xi-Han Li, Chun-Yan Li, Ping Zhou and Hong-Yu Zhou
|
Economical Quantum Secure Direct Communication Network with Single
Photons
|
6 pages, 3 figures
|
Chinese Physics 16 (12), 3553-3559 (2007)
|
10.1088/1009-1963/16/12/001
| null |
quant-ph
| null |
A scheme for quantum secure direct communication (QSDC) network is proposed
with a sequence of polarized single photons. The single photons are prepared
originally in the same state |0> by the servers on the network, which will
reduce the difficulty for the legitimate users to check eavesdropping largely.
The users code the information on the single photons with two unitary
operations which do not change their measuring bases. Some decoy photons, which
are produced by operating the sample photons with a Hadamard, are used for
preventing a potentially dishonest server from eavesdropping the quantum lines
freely. This scheme is an economical one as it is the easiest way for QSDC
network communication securely.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 07:36:34 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Dec 2007 10:10:35 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Deng",
"Fu-Guo",
""
],
[
"Li",
"Xi-Han",
""
],
[
"Li",
"Chun-Yan",
""
],
[
"Zhou",
"Ping",
""
],
[
"Zhou",
"Hong-Yu",
""
]
] |
quant-ph/0606009
|
Yatendra Jain
|
Yatendra S. Jain
|
Untouched aspects of the wave mechanics of a particle in one dimensional
box
|
8 pages no figure
| null | null | null |
quant-ph
| null |
Wave mechanics of a particle in 1-D box (size $= d$) is critically analyzed
to reveal its untouched aspects. When the particle rests in its ground state,
its zero-point force ($F_o$) produces non-zero strain by modifying the box size
from $d$ to $d' = d + \Delta d$ in all practical situations where the force
($F_a$) restoring $d$ is not infinitely strong. Assuming that $F_a$ originates
from a potential $\propto x^2$ ($x$ being a small change in $d$), we find that:
(i) the particle and strained box assume a mutually bound state (under the
equilibrium between $F_o$ and $F_a$) with binding energy $\Delta{E} =
-\epsilon_o'\Delta{d}/d'$ (with $\epsilon_o' = h^2/8md'^2$ being the ground
state energy of the particle in the strained box), (ii) the box size oscillates
around $d'$ when the said equilibrium is disturbed, (iii) an exchange of energy
between the particle and the strained box occurs during such oscillations, and
(iv) the particle, having collisional motion in its excited states, assumes
collisionless motion in its ground state. These aspects have desired
experimental support and proven relevance for understanding the physics of
widely different systems such as quantum dots, quantum wires, trapped single
particle/ion, clusters of particles, superconductors, superfluids, {\it etc.}
It is emphasized that the physics of such a system in its low energy states can
be truly revealed if the theory incorporates $F_o$ and related aspects.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 08:39:53 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Jain",
"Yatendra S.",
""
]
] |
quant-ph/0606010
|
Marco Barbieri
|
M. Barbieri, C. Cinelli, F. De Martini, P. Mataloni
|
Generation of polarization entangled photon pairs by a single crystal
interferometric source pumped by femtosecond laser pulses
| null | null |
10.1134/S1054660X06100069
| null |
quant-ph
| null |
Photon pairs, highly entangled in polarization have been generated under
femtosecond laser pulse excitation by a type I crystal source, operating in a
single arm interferometric scheme. The relevant effects of temporal walk-off
existing in these conditions between the ordinary and extraordinary photons
were experimentally investigated. By introducing a suitable temporal
compensation between the two orthogonal polarization components highly
entangled pulsed states were obtained.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 09:46:53 GMT"
},
{
"version": "v2",
"created": "Tue, 6 Jun 2006 09:58:33 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Barbieri",
"M.",
""
],
[
"Cinelli",
"C.",
""
],
[
"De Martini",
"F.",
""
],
[
"Mataloni",
"P.",
""
]
] |
quant-ph/0606011
|
N. L. Harshman
|
N. L. Harshman
|
Dynamical Entanglement in Non-Relativistic, Elastic Scattering
|
4 pages, no figs., submission to conf. proc. of Quantum 2006, III
Workshop ad memoriam of Carlo Novero
|
Int. J. Quant. Inf. 5 (2007) 273-278
| null | null |
quant-ph
| null |
This article considers dynamical entanglement in non-relativistic particle
scattering. Three questions are explored: what kinds of entanglement occur in
this system, how do global symmetries constrain entanglement, and how do the
boundary conditions of scattering affect dynamical entanglement? First, a
simple model of scattering spin systems is considered, then the full system is
discussed.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 09:49:40 GMT"
}
] | 2008-04-16T00:00:00 |
[
[
"Harshman",
"N. L.",
""
]
] |
quant-ph/0606012
|
Quesne Christiane
|
B. Bagchi, A. Banerjee, C. Quesne
|
PT-symmetric quartic anharmonic oscillator and position-dependent mass
in a perturbative approach
|
8 pages, no figure, to appear in special issue of Czech. J. Phys
|
Czech.J.Phys.56:893-898,2006
|
10.1007/s10582-006-0385-y
|
ULB/229/CQ/06/3
|
quant-ph hep-th math-ph math.MP
| null |
To lowest order of perturbation theory we show that an equivalence can be
established between a $\cal PT$-symmetric generalized quartic anharmonic
oscillator model and a Hermitian position-dependent mass Hamiltonian $h$. An
important feature of $h$ is that it reveals a domain of couplings where the
quartic potential could be attractive, vanishing or repulsive. We also
determine the associated physical quantities.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 12:52:49 GMT"
}
] | 2008-11-26T00:00:00 |
[
[
"Bagchi",
"B.",
""
],
[
"Banerjee",
"A.",
""
],
[
"Quesne",
"C.",
""
]
] |
quant-ph/0606013
|
Mihai Macovei
|
M. Macovei, Z. Ficek, C. H. Keitel
|
Collective coherent population trapping in a thermal field
|
Accepted for publication in Phys. Rev. A
|
Phys. Rev. A 73, 063821 (2006)
|
10.1103/PhysRevA.73.063821
| null |
quant-ph
| null |
We analyzed the efficiency of coherent population trapping (CPT) in a
superposition of the ground states of three-level atoms under the influence of
the decoherence process induced by a broadband thermal field. We showed that in
a single atom there is no perfect CPT when the atomic transitions are affected
by the thermal field. The perfect CPT may occur when only one of the two atomic
transitions is affected by the thermal field. In the case when both atomic
transitions are affected by the thermal field, we demonstrated that regardless
of the intensity of the thermal field the destructive effect on the CPT can be
circumvented by the collective behavior of the atoms. An analytic expression
was obtained for the populations of the upper atomic levels which can be
considered as a measure of the level of thermal decoherence. The results show
that the collective interaction between the atoms can significantly enhance the
population trapping in that the population of the upper state decreases with
increased number of atoms. The physical origin of this feature was explained by
the semiclassical dressed atom model of the system. We introduced the concept
of multiatom collective coherent population trapping by demonstrating the
existence of collective (entangled) states whose storage capacity is larger
than that of the equivalent states of independent atoms.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 15:11:31 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Macovei",
"M.",
""
],
[
"Ficek",
"Z.",
""
],
[
"Keitel",
"C. H.",
""
]
] |
quant-ph/0606014
|
Rom\`an R. Zapatrin
|
George Parfionov, Roman R. Zapatrin
|
How `hot' are mixed quantum states?
|
Contribution to Quantum 2006: III workshop ad memoriam of Carlo
Novero: Advances in Foundations of Quantum Mechanics and Quantum Information
with atoms and photons. 2-5 May 2006 - Turin, Italy
|
International Journal of Quantum Information (IJQI), Volume: 5,
311-317 (2007)
|
10.1142/S0219749907002803
| null |
quant-ph
| null |
Given a mixed quantum state $\rho$ of a qudit, we consider any observable $M$
as a kind of `thermometer' in the following sense. Given a source which emits
pure states with these or those distributions, we select such distributions
that the appropriate average value of the observable $M$ is equal to the
average Tr$M\rho$ of $M$ in the stare $\rho$. Among those distributions we find
the most typical one, namely, having the highest differential entropy. We call
this distribution conditional Gibbs ensemble as it turns out to be a Gibbs
distribution characterized by a temperature-like parameter $\beta$. The
expressions establishing the liaisons between the density operator $\rho$ and
its temperature parameter $\beta$ are provided. Within this approach, the
uniform mixed state has the highest `temperature', which tends to zero as the
state in question approaches to a pure state.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 16:44:19 GMT"
}
] | 2009-09-23T00:00:00 |
[
[
"Parfionov",
"George",
""
],
[
"Zapatrin",
"Roman R.",
""
]
] |
quant-ph/0606015
|
Zhaohui Wei
|
Zhaohui Wei, Zhengfeng Ji and Mingsheng Ying
|
Majorization in Quantum Adiabatic Algorithms
|
7 pages;1 figure
|
Phys. Rev. A 74, 042320(2006)
|
10.1103/PhysRevA.74.042320
| null |
quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The majorization theory has been applied to analyze the mathematical
structure of quantum algorithms. An empirical conclusion by numerical
simulations obtained in the previous literature indicates that step-by-step
majorization seems to appear universally in quantum adiabatic algorithms. In
this paper, a rigorous analysis of the majorization arrow in a special class of
quantum adiabatic algorithms is carried out. In particular, we prove that for
any adiabatic algorithm of this class, step-by-step majorization of the ground
state holds exactly. For the actual state, we show that step-by-step
majorization holds approximately, and furthermore that the longer the running
time of the algorithm, the better the approximation.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 16:52:11 GMT"
},
{
"version": "v2",
"created": "Tue, 27 Jun 2006 16:43:10 GMT"
},
{
"version": "v3",
"created": "Wed, 1 Sep 2010 02:47:13 GMT"
}
] | 2010-09-02T00:00:00 |
[
[
"Wei",
"Zhaohui",
""
],
[
"Ji",
"Zhengfeng",
""
],
[
"Ying",
"Mingsheng",
""
]
] |
quant-ph/0606016
|
Viv Kendon
|
Viv Kendon (U Leeds)
|
Decoherence in quantum walks - a review
|
52 pages, invited review, v2 & v3 updates to include significant work
since first posted and corrections from comments received; some non-trivial
typos fixed. Comments now limited to changes that can be applied at proof
stage
|
Math. Struct. in Comp. Sci 17(6) pp 1169-1220 (2006)
|
10.1017/S0960129507006354
| null |
quant-ph
| null |
The development of quantum walks in the context of quantum computation, as
generalisations of random walk techniques, led rapidly to several new quantum
algorithms. These all follow unitary quantum evolution, apart from the final
measurement. Since logical qubits in a quantum computer must be protected from
decoherence by error correction, there is no need to consider decoherence at
the level of algorithms. Nonetheless, enlarging the range of quantum dynamics
to include non-unitary evolution provides a wider range of possibilities for
tuning the properties of quantum walks. For example, small amounts of
decoherence in a quantum walk on the line can produce more uniform spreading (a
top-hat distribution), without losing the quantum speed up. This paper reviews
the work on decoherence, and more generally on non-unitary evolution, in
quantum walks and suggests what future questions might prove interesting to
pursue in this area.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 17:01:23 GMT"
},
{
"version": "v2",
"created": "Sat, 26 Aug 2006 22:09:19 GMT"
},
{
"version": "v3",
"created": "Sun, 26 Nov 2006 00:18:05 GMT"
}
] | 2008-03-02T00:00:00 |
[
[
"Kendon",
"Viv",
"",
"U Leeds"
]
] |
quant-ph/0606017
|
Steven J. van Enk
|
S.J. van Enk
|
Can measuring entanglement be easy?
|
No
| null | null | null |
quant-ph
| null |
I raise some doubts concerning a protocol recently applied in an experiment
(Walborn et al, Nature) to measure entanglement. The protocol is much simpler
than other known entanglement-verification methods, but, I argue, needs
assumptions (namely that the state generated is known and pure) that are too
strong to be allowed and that are not justified in most experiments. An
extension of the protocol suggested in quant-ph/0605250 is much harder to
implement and still relies on assumptions not justified in
entanglement-verification protocols, as demonstrated by an explicit example.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 17:48:18 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"van Enk",
"S. J.",
""
]
] |
quant-ph/0606018
|
Juergen Eschner
|
Matthias Schulz, Herbert Crepaz, Ferdinand Schmidt-Kaler, Juergen
Eschner, Rainer Blatt
|
Transfer of trapped atoms between two optical tweezer potentials
| null | null |
10.1080/09500340600861740
| null |
quant-ph
| null |
Trapped, laser-cooled rubidium atoms are transferred between two strongly
focused, horizontal, orthogonally intersecting laser beams. The transfer
efficiency is studied as a function of the vertical distance between the beam
axes. Optimum transfer is found when the distance equals the beam waist radius.
Numerical simulations reproduce well the experimental results.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 18:34:43 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Schulz",
"Matthias",
""
],
[
"Crepaz",
"Herbert",
""
],
[
"Schmidt-Kaler",
"Ferdinand",
""
],
[
"Eschner",
"Juergen",
""
],
[
"Blatt",
"Rainer",
""
]
] |
quant-ph/0606019
|
William E. Baylis
|
W. E. Baylis, R. Cabrera, C. Rangan
|
Control and Representation of n-qubit Quantum Systems
|
4 pages, no figures, revision corrects a couple of minor errors
| null | null | null |
quant-ph
| null |
Just as any state of a single qubit or 2-level system can be obtained from
any other state by a rotation operator parametrized by three real Euler angles,
we show how any state of an n-qubit or 2^n-level system can be obtained from
any other by a compact unitary transformation with 2^(n+1)-1 real angles, 2^n
of which are azimuthal-like and the rest polar-like. The results follow from a
modeling of the Hilbert space of n-qubits by a minimal left ideal of an
associative algebra. This representation is expected to be useful in the design
of new compact control techniques or more efficient algorithms in quantum
computing.
|
[
{
"version": "v1",
"created": "Thu, 1 Jun 2006 21:36:19 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Jul 2006 21:05:09 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Baylis",
"W. E.",
""
],
[
"Cabrera",
"R.",
""
],
[
"Rangan",
"C.",
""
]
] |
quant-ph/0606020
|
Pavel Exner
|
Pavel Exner, Martin Fraas
|
Resonance asymptotics in the generalized Winter model
|
LaTeX, 10 pages with one figure
|
Phys. Lett. A360 (2006), 57-61
|
10.1016/j.physleta.2006.07.073
| null |
quant-ph math-ph math.MP
| null |
We consider a modification of the Winter model describing a quantum particle
in presence of a spherical barrier given by a fixed generalized point
interaction. It is shown that the three classes of such interactions correspond
to three different types of asymptotic behaviour of resonances of the model at
high energies.
|
[
{
"version": "v1",
"created": "Fri, 2 Jun 2006 08:37:39 GMT"
}
] | 2020-02-07T00:00:00 |
[
[
"Exner",
"Pavel",
""
],
[
"Fraas",
"Martin",
""
]
] |
quant-ph/0606021
|
Fu-Guo Deng
|
Fu-Guo Deng, Xi-Han Li, Chun-Yan Li, Ping Zhou, Yu-Jie Liang and
Hong-Yu Zhou
|
Multiparty Quantum Secret Report
|
4 pages, no figures
|
Chinese Physics Letters 23, 1676 (2006)
|
10.1088/0256-307X/23/7/006
| null |
quant-ph
| null |
A multiparty quantum secret report scheme is proposed with quantum
encryption. The boss Alice and her $M$ agents first share a sequence of
($M$+1)-particle Greenberger--Horne--Zeilinger (GHZ) states that only Alice
knows which state each ($M$+1)-particle quantum system is in. Each agent
exploits a controlled-not (CNot) gate to encrypt the travelling particle by
using the particle in the GHZ state as the control qubit. The boss Alice
decrypts the travelling particle with a CNot gate after performing a $\sigma_x$
operation on her particle in the GHZ state or not. After the GHZ states (the
quantum key) are used up, the parties check whether there is a vicious
eavesdropper, say Eve, monitoring the quantum line, by picking out some samples
from the GHZ states shared and measure them with two measuring bases. After
confirming the security of the quantum key, they use the GHZ states remained
repeatedly for next round of quantum communication. This scheme has the
advantage of high intrinsic efficiency for qubits and the total efficiency.
|
[
{
"version": "v1",
"created": "Fri, 2 Jun 2006 11:55:44 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Deng",
"Fu-Guo",
""
],
[
"Li",
"Xi-Han",
""
],
[
"Li",
"Chun-Yan",
""
],
[
"Zhou",
"Ping",
""
],
[
"Liang",
"Yu-Jie",
""
],
[
"Zhou",
"Hong-Yu",
""
]
] |
quant-ph/0606022
|
Matthew Saul Leifer
|
M. S. Leifer
|
Quantum Dynamics as an analog of Conditional Probability
|
16 pages, 3 figures. v2 Presentation greatly improved, references
updated and typos fixed
|
Phys. Rev. A 74, 042310 (2006)
|
10.1103/PhysRevA.74.042310
| null |
quant-ph
| null |
Quantum theory can be regarded as a non-commutative generalization of
classical probability. From this point of view, one expects quantum dynamics to
be analogous to classical conditional probabilities. In this paper, a variant
of the well-known isomorphism between completely positive maps and bipartite
density operators is derived, which makes this connection much more explicit.
The new isomorphism is given an operational interpretation in terms of
statistical correlations between ensemble preparation procedures and outcomes
of measurements. Finally, the isomorphism is applied to elucidate the
connection between no-cloning/no-broadcasting theorems and the monogamy of
entanglement, and a simplified proof of the no-broadcasting theorem is obtained
as a byproduct.
|
[
{
"version": "v1",
"created": "Fri, 2 Jun 2006 15:21:35 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Jun 2006 00:26:51 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Leifer",
"M. S.",
""
]
] |
quant-ph/0606023
|
Rolando Somma
|
R. D. Somma, J. Chiaverini, D. J. Berkeland
|
Lower bounds for the fidelity of entangled state preparation
|
8 pages, 2 figures. Added discussion about rotational-invariant
states
| null |
10.1103/PhysRevA.74.052302
| null |
quant-ph
| null |
Estimating the fidelity of state preparation in multi-qubit systems is
generally a time-consuming task. Nevertheless, this complexity can be reduced
if the desired state can be characterized by certain symmetries measurable with
the corresponding experimental setup. In this paper we give simple expressions
to estimate the fidelity of multi-qubit state preparation for
rotational-invariant, stabilizer, and generalized coherent states. We
specifically discuss the cat, W-type, and generalized coherent states, and
obtain efficiently measurable lower bounds for the fidelity. We use these
techniques to estimate the fidelity of a quantum simulation of an Ising-like
interacting model using two trapped ions. These results are directly applicable
to experiments using fidelity-based entanglement witnesses, such as quantum
simulations and quantum computation.
|
[
{
"version": "v1",
"created": "Fri, 2 Jun 2006 16:03:16 GMT"
},
{
"version": "v2",
"created": "Fri, 9 Jun 2006 20:38:44 GMT"
},
{
"version": "v3",
"created": "Thu, 20 Jul 2006 17:11:50 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Somma",
"R. D.",
""
],
[
"Chiaverini",
"J.",
""
],
[
"Berkeland",
"D. J.",
""
]
] |
quant-ph/0606024
|
Diego A. Wisniacki
|
Fabricio Toscano and Diego A. Wisniacki
|
Quantum to classical transition in a system with a mixed classical
dynamics
|
10 pages, 7 figures
|
Phys. Rev. E 74 056208 (2006)
|
10.1103/PhysRevE.74.056208
| null |
quant-ph nlin.CD
| null |
We study how decoherence rules the quantum-classical transition of the Kicked
Harmonic Oscillator (KHO). When the amplitude of the kick is changed the system
presents a classical dynamics that range from regular to a strong chaotic
behavior. We show that for regular and mixed classical dynamics, and in the
presence of noise, the distance between the classical and the quantum phase
space distributions is proportional to a single parameter $\chi\equiv
K\hbar_{\rm eff}^2/4D^{3/2}$ which relates the effective Planck constant
$\hbar_{\rm eff}$, the kick amplitude $K$ and the diffusion constant $D$. This
is valid when $\chi < 1$, a case that is always attainable in the semiclassical
regime independently of the value of the strength of noise given by $D$. Our
results extend a recent study performed in the chaotic regime.
|
[
{
"version": "v1",
"created": "Fri, 2 Jun 2006 16:21:59 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Toscano",
"Fabricio",
""
],
[
"Wisniacki",
"Diego A.",
""
]
] |
quant-ph/0606025
|
Thomas B. Bahder
|
Paul A. Lopata, Thomas B. Bahder
|
Sending Sensitive Messages in Quantum Packages
|
4 pages, 2 tables, and no figures
| null | null | null |
quant-ph
| null |
A communication protocol is introduced that allows the receiver of a message
to place an a posteriori bound on the amount of information that an
eavesdropper could have obtained during transmission of that message. This
quantum cryptographic protocol is distinct from quantum key distribution. The
quantum states and measurements required by this protocol are simple enough
that it can be implemented using existing technology.
|
[
{
"version": "v1",
"created": "Fri, 2 Jun 2006 19:23:24 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Lopata",
"Paul A.",
""
],
[
"Bahder",
"Thomas B.",
""
]
] |
quant-ph/0606026
|
Shohini Ghose
|
Shohini Ghose and Barry C. Sanders
|
Non-Gaussian states for continuous variable quantum computation via
Gaussian maps
|
8 pages, 6 figures
|
Journal of Modern Optics, 54, 855 (2007)
|
10.1080/09500340601101575
| null |
quant-ph
| null |
We investigate non-Gaussian states of light as ancillary inputs for
generating nonlinear transformations required for quantum computing with
continuous variables. We consider a recent proposal for preparing a cubic phase
state, find the exact form of the prepared state and perform a detailed
comparison to the ideal cubic phase state. We thereby identify the main
challenges to preparing an ideal cubic phase state and describe the gates
implemented with the non-ideal prepared state. We also find the general form of
operations that can be implemented with ancilla Fock states, together with
Gaussian input states, linear optics and squeezing transformations, and
homodyne detection with feed forward, and discuss the feasibility of continuous
variable quantum computing using ancilla Fock states.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 03:02:31 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 17:43:41 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Ghose",
"Shohini",
""
],
[
"Sanders",
"Barry C.",
""
]
] |
quant-ph/0606027
|
A. D. Alhaidari
|
A. D. Alhaidari, H. Bahlouli, M. S. Abdelmonem, F. S. Al-Ameen, and T.
H. Al-Abdulaal
|
Scattering theory with a natural regularization: Rediscovering the
J-matrix method
|
10 pages
|
Physics Letters A 364.5 (2007) 372--377
|
10.1016/j.physleta.2006.12.027
| null |
quant-ph
| null |
In three dimensional scattering, the energy continuum wavefunction is
obtained by utilizing two independent solutions of the reference wave equation.
One of them is typically singular (usually, near the origin of configuration
space). Both are asymptotically regular and sinusoidal with a phase difference
(shift) that contains information about the scattering potential. Therefore,
both solutions are essential for scattering calculations. Various
regularization techniques were developed to handle the singular solution
leading to different well-established scattering methods. To simplify the
calculation the regularized solutions are usually constructed in a space that
diagonalizes the reference Hamiltonian. In this work, we start by proposing
solutions that are already regular. We write them as infinite series of square
integrable basis functions that are compatible with the domain of the reference
Hamiltonian. However, we relax the diagonal constraint on the representation by
requiring that the basis supports an infinite tridiagonal matrix representation
of the wave operator. The hope is that by relaxing this constraint on the
solution space a larger freedom is achieved in regularization such that a
natural choice emerges as a result. We find that one of the resulting two
independent wavefunctions is, in fact, the regular solution of the reference
problem. The other is uniquely regularized in the sense that it solves the
reference wave equation only outside a dense region covering the singularity in
configuration space. However, asymptotically it is identical to the irregular
solution. We show that this natural and special regularization is equivalent to
that already used in the J-matrix method of scattering.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 18:19:36 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Alhaidari",
"A. D.",
""
],
[
"Bahlouli",
"H.",
""
],
[
"Abdelmonem",
"M. S.",
""
],
[
"Al-Ameen",
"F. S.",
""
],
[
"Al-Abdulaal",
"T. H.",
""
]
] |
quant-ph/0606028
|
A. R. P. Rau
|
A.R.P.Rau
|
Quantum Interpretations
|
13 pages
| null |
10.4006/1.3025810
| null |
quant-ph
| null |
Difficulties and discomfort with the interpretation of quantum mechanics are
due to differences in language between it and classical physics. Analogies to
The Special Theory of Relativity, which also required changes in the basic
worldview and language of non-relativistic classical mechanics, may help in
absorbing the changes called for by quantum physics. There is no need to invoke
extravagances such as the many worlds interpretation or specify a central role
for consciousness or neural microstructures. The simple, but basic, acceptance
that what is meant by the state of a physical system is different in quantum
physics from what it is in classical physics goes a long way in explaining its
seeming peculiarities.
|
[
{
"version": "v1",
"created": "Sat, 3 Jun 2006 20:56:07 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Rau",
"A. R. P.",
""
]
] |
quant-ph/0606029
|
Hong Shen
|
S. Yang, Z. Song, C.P. Sun
|
Dynamic generation of entangling wave packets in XY spin system with
decaying long range couplings
|
7 pages, 6 figures
|
Sci. China Ser. G 51, 45 (2008)
|
10.1007/s11433-008-0002-0
| null |
quant-ph cond-mat.mes-hall
| null |
We study the dynamic generation of spin entanglement between two distant
sites in an XY model with $1/r^{2}$-decay long range couplings. Due to the
linear dispersion relation $\epsilon (k)\sim |k|$ of magnons in such model, we
show that a well-located spin state can be dynamically split into two moving
entangled local wave packets without changing their shapes. Interestingly, when
such two wave packets meet at the diametrically opposite site after the fast
period $\tau =\pi $, the initial well-located state can be recurrent
completely. Numerical calculation is performed to confirm the analytical result
even the ring system of sizes $N$ up to several thousands are considered. The
truncation approximation for the coupling strengths is also studied. Numerical
simulation shows that the above conclusions still hold even the range of the
coupling strength is truncated at a relative shorter scale comparing to the
size of the spin system.
|
[
{
"version": "v1",
"created": "Sun, 4 Jun 2006 21:53:20 GMT"
}
] | 2010-02-09T00:00:00 |
[
[
"Yang",
"S.",
""
],
[
"Song",
"Z.",
""
],
[
"Sun",
"C. P.",
""
]
] |
quant-ph/0606030
|
Toyohiro Tsurumaru
|
Toyohiro Tsurumaru
|
Group Covariant Protocols for Quantum String Commitment
|
5 pages, no figure, typos corrected
|
Phys. Rev. A, 74, 042307 (2006)
|
10.1103/PhysRevA.74.042307
| null |
quant-ph
| null |
We study the security of quantum string commitment (QSC) protocols with group
covariant encoding scheme. First we consider a class of QSC protocol, which is
general enough to incorporate all the QSC protocols given in the preceding
literatures. Then among those protocols, we consider group covariant protocols
and show that the exact upperbound on the binding condition can be calculated.
Next using this result, we prove that for every irreducible representation of a
finite group, there always exists a corresponding nontrivial QSC protocol which
reaches a level of security impossible to achieve classically.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 08:42:39 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Oct 2006 07:06:37 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Tsurumaru",
"Toyohiro",
""
]
] |
quant-ph/0606031
|
Suresh Tiwari dr
|
S. C. Tiwari
|
Photon Spin, Zero-point Energy and Black-body radiation
|
Submitted for publication
| null | null | null |
quant-ph
| null |
A critical review of the obscure nature of the contribution of spin energy to
the energy of the electromagnetic field is presented. It is proposed that the
total energy of photon h\nu comprises of kinetic and spin parts each equal to
h\nu/2. Classical magnetic field is reinterpreted as angular momentum flux of
photon fluid. The black-body radiation law is revisited in the light of new
significance of the zero-point energy proposed here.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 08:48:14 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Tiwari",
"S. C.",
""
]
] |
quant-ph/0606032
|
Michele Caponigro
|
Michele Caponigro, Helen Lynn
|
Quantum Mechanics: 44 Admissible Questions? -Not only Fapp-
|
2 pages
| null | null | null |
quant-ph
| null |
The words: determinism, hidden variables, subjectivism, information,
objectivism, informational-theoretic axioms,observers have some connection with
physical reality? What we mean with "description" of physical reality? When we
say that we understand this reality? Certain parameters:position, velocity are
sufficient? We will focus only to conceptual considerations regarding the
relation between the "questions" and the relative "answers" in general and
specifically in quantum mechanics. It is usually believed that the answers are
more important of the questions, for this reason we can read many answers
everywhere and in different field of knowledge. We need to add and clarify some
things: (i) usually an answers require a question, (ii) but, as we know, their
relation is not so simple and immediate, (iii) For instance: a)an epistemic
questions give us ontic answers? b)the answer has a connection with the
question and vice versa? c)we could to infer a question starting from an
answer? d)there are answers without questions? These answers could be in some
framework considered as ontic answers? The relative scientific works are the
same time ontic? Speaking of quantum mechanics we see around many answers in
the meantime we do not see the correspondent questions, these answers seem
completely independent, and this seem a right road, the road of the independent
nature unlinked from human thoughts. We retain instead that questions can
affect the possible answers. Exist "something" before the question?
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 11:40:15 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Caponigro",
"Michele",
""
],
[
"Lynn",
"Helen",
""
]
] |
quant-ph/0606033
|
Takao Aoki
|
Takao Aoki, Barak Dayan, E. Wilcut, W. P. Bowen, A. S. Parkins, H. J.
Kimble, T. J. Kippenberg, K. J. Vahala
|
Observation of Strong Coupling between One Atom and a Monolithic
Microresonator
| null |
Nature 443, 671 (2006)
|
10.1038/nature05147
| null |
quant-ph
| null |
Over the past decade, strong interactions of light and matter at the
single-photon level have enabled a wide set of scientific advances in quantum
optics and quantum information science. This work has been performed
principally within the setting of cavity quantum electrodynamics with diverse
physical systems, including single atoms in Fabry-Perot resonators, quantum
dots coupled to micropillars and photonic bandgap cavities, and Cooper-pairs
interacting with superconducting resonators. Experiments with single, localized
atoms have been at the forefront of these advances with the use of optical
resonators in high-finesse Fabry-Perot configurations. As a result of the
extreme technical challenges involved in further improving the multilayer
dielectric mirror coatings of these resonators and in scaling to large numbers
of devices, there has been increased interest in the development of alternative
microcavity systems. Here we show strong coupling between individual Cesium
atoms and the fields of a high-quality toroidal microresonator. From
observations of transit events for single atoms falling through the resonator's
evanescent field, we determine the coherent coupling rate for interactions near
the surface of the resonator. We develop a theoretical model to quantify our
observations, demonstrating that strong coupling is achieved, with the rate of
coherent coupling exceeding the dissipative rates of the atom and the cavity.
Our work opens the way for investigations of optical processes with single
atoms and photons in lithographically fabricated microresonators. Applications
include the implementation of quantum networks, scalable quantum logic with
photons, and quantum information processing on atom chips.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 14:14:34 GMT"
},
{
"version": "v2",
"created": "Mon, 4 Sep 2006 16:56:29 GMT"
}
] | 2014-05-06T00:00:00 |
[
[
"Aoki",
"Takao",
""
],
[
"Dayan",
"Barak",
""
],
[
"Wilcut",
"E.",
""
],
[
"Bowen",
"W. P.",
""
],
[
"Parkins",
"A. S.",
""
],
[
"Kimble",
"H. J.",
""
],
[
"Kippenberg",
"T. J.",
""
],
[
"Vahala",
"K. J.",
""
]
] |
quant-ph/0606034
|
Fei Gao
|
Fei Gao, Qiao-Yan Wen, Fu-Chen Zhu
|
Improving the security of quantum exam against cheating
|
6 pages, no figure; Submitted to Phys. Lett. A on March 10,2006
|
Phys. Lett. A 360 (2007) 748-750, with the changed title "Comment
on: "Quantum exam" [Phys. Lett. A 350 (2006) 174]"
|
10.1016/j.physleta.2006.08.016
| null |
quant-ph
| null |
The security of quantum exam [Phys. Lett. A 350 (2006) 174] is analyzed and
it is found that this protocol is secure for any eavesdropper except for the
"students" who take part in the exam. Specifically, any student can steal other
examinees' solutions and then cheat in the exam. Furthermore, a possible
improvement of this protocol is presented.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 14:20:52 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Gao",
"Fei",
""
],
[
"Wen",
"Qiao-Yan",
""
],
[
"Zhu",
"Fu-Chen",
""
]
] |
quant-ph/0606035
|
Andrew Fletcher
|
Andrew S. Fletcher, Peter W. Shor, and Moe Z. Win
|
Optimum Quantum Error Recovery using Semidefinite Programming
|
7 pages, 3 figures
| null |
10.1103/PhysRevA.75.012338
| null |
quant-ph
| null |
Quantum error correction (QEC) is an essential element of physical quantum
information processing systems. Most QEC efforts focus on extending classical
error correction schemes to the quantum regime. The input to a noisy system is
embedded in a coded subspace, and error recovery is performed via an operation
designed to perfectly correct for a set of errors, presumably a large subset of
the physical noise process. In this paper, we examine the choice of recovery
operation. Rather than seeking perfect correction on a subset of errors, we
seek a recovery operation to maximize the entanglement fidelity for a given
input state and noise model. In this way, the recovery operation is optimum for
the given encoding and noise process. This optimization is shown to be
calculable via a semidefinite program (SDP), a well-established form of convex
optimization with efficient algorithms for its solution. The error recovery
operation may also be interpreted as a combining operation following a quantum
spreading channel, thus providing a quantum analogy to the classical diversity
combining operation.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 17:36:08 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Fletcher",
"Andrew S.",
""
],
[
"Shor",
"Peter W.",
""
],
[
"Win",
"Moe Z.",
""
]
] |
quant-ph/0606036
|
Paula Villar
|
Fernando C. Lombardo and Paula I. Villar
|
Geometric phases in open systems: an exact model to study how they are
corrected by decoherence
|
Revtex 4, 5 pages, one eps figure. Version Published
|
Physical Review A 74, 042311 (2006)
|
10.1103/PhysRevA.74.042311
| null |
quant-ph
| null |
We calculate the geometric phase for an open system (spin-boson model) which
interacts with an environment (ohmic or nonohmic) at arbitrary temperature.
However there have been many assumptions about the time scale at which the
geometric phase can be measured, there has been no reported observation yet for
mixed states under nonunitary evolution. We study not only how they are
corrected by the presence of the different type of environments but also
estimate the corresponding times at which decoherence becomes effective. These
estimations should be taken into account when planning experimental setups to
study the geometric phase in the nonunitary regime, particularly important for
the application of fault-tolerant quantum computation.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 21:48:21 GMT"
},
{
"version": "v2",
"created": "Thu, 12 Oct 2006 21:55:15 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Lombardo",
"Fernando C.",
""
],
[
"Villar",
"Paula I.",
""
]
] |
quant-ph/0606037
|
Nathan Lundblad
|
N. Lundblad, R. J. Thompson, D. C. Aveline, L. Maleki
|
Spinor Dynamics-Driven Formation of a Dual-Beam Atom Laser
|
4 pages, 4 figures
|
Optics Express 14,10164 (2006)
|
10.1364/OE.14.010164
| null |
quant-ph physics.atom-ph
| null |
We demonstrate a novel dual-beam atom laser formed by outcoupling oppositely
polarized components of an F=1 spinor Bose-Einstein condensate whose Zeeman
sublevel populations have been coherently evolved through spin dynamics. The
condensate is formed through all-optical means using a single-beam running-wave
dipole trap. We create a condensate in the field-insensitive $m_F=0$ state, and
drive coherent spin-mixing evolution through adiabatic compression of the
initially weak trap. Such dual beams, number-correlated through the angular
momentum-conserving reaction $2m_0\leftrightharpoons m_{+1}+m_{-1}$, have been
proposed as tools to explore entanglement and squeezing in Bose-Einstein
condensates, and have potential use in precision phase measurements.
|
[
{
"version": "v1",
"created": "Mon, 5 Jun 2006 21:49:53 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Lundblad",
"N.",
""
],
[
"Thompson",
"R. J.",
""
],
[
"Aveline",
"D. C.",
""
],
[
"Maleki",
"L.",
""
]
] |
quant-ph/0606038
|
Joseph Johnson
|
Joseph F. Johnson
|
Remarks on an attempted axiomatisation of Quantum Mechanics, due to
Lucien Hardy, and Ten Theses on Hilbert's Sixth Problem and Quantum
Measurement
|
see http://arxiv.org/abs/quant-ph/0502124 and
http://euclid.unh.edu/~jjohnson/axiomatics.html for larger context and
further references
| null | null | null |
quant-ph
| null |
From the standpoint of Hilbert's Sixth Problem, which is the axiomatisation
of Physics, the famous paper of Lucien Hardy's, Quantum Theory from Five
Reasonable Axioms, is not relevant. The present paper argues that Hardy does
not give a physical definition of `limit', and if we assume the usual
mathematical definition of limit of a sequence, he fails to define a sequence
in physical terms to which the usual definition is applicable. We argue that
one should not, in fact, try to define probability in terms of the usual notion
of limit of a sequence of results of a measurement because of seemingly
insurmountable difficulties in axiomatising the notion of function or sequence
in this context. Von Plato's and the authour's work (see
http:arxiv.org/abs/quant-ph/0502124 and
euclid.unh.edu/~jjohnson/axiomatics.html for larger context and further
references) on the definition of physical probability needs to be used in this
context. We conclude with ten theses on quantum measurement, from the
standpoint of the Hilbert problem.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 02:10:42 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Jun 2006 02:28:06 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Johnson",
"Joseph F.",
""
]
] |
quant-ph/0606039
|
Safa Jami
|
Safa Jami, Mohsen Sarbishei
|
Degree of entanglement for qubit-qutrit state
| null | null | null | null |
quant-ph
| null |
In this paper we consider a system consist of a qubit and a qutrit, and find
a formula to evaluate the concurrence for it. We show that entanglement of
formation for this system obeys the same relation as for two-qubits.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 08:11:51 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Jami",
"Safa",
""
],
[
"Sarbishei",
"Mohsen",
""
]
] |
quant-ph/0606040
|
Grigori Amosov
|
Grigori Amosov
|
On the additivity conjecture for the Weyl channels being covariant with
respect to the maximum commutative group of unitaries
|
3 pages, a completely revised version
| null | null | null |
quant-ph
| null |
Some new examples of quantum channels for which the infimum of the output
entropy is additive under taking a tensor product of channels are given.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 08:18:42 GMT"
},
{
"version": "v2",
"created": "Tue, 13 Jun 2006 16:28:43 GMT"
},
{
"version": "v3",
"created": "Sat, 9 Sep 2006 11:18:37 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Amosov",
"Grigori",
""
]
] |
quant-ph/0606041
|
Johannes Kofler
|
Michael Lindenthal, Johannes Kofler
|
Measuring the absolute photo detection efficiency using photon number
correlations
|
6 pages, 1 figure, journal reference added
|
Appl. Opt. 45, 6059 (2006)
|
10.1364/AO.45.006059
| null |
quant-ph
| null |
We present two methods for determining the absolute detection efficiency of
photon-counting detectors directly from their singles rates under illumination
from a nonclassical light source. One method is based on a continuous variable
analogue to coincidence counting in discrete photon experiments, but does not
actually rely on high detector time resolutions. The second method is based on
difference detection which is a typical detection scheme in continuous variable
quantum optics experiments. Since no coincidence detection is required with
either method, they are useful for detection efficiency measurements of photo
detectors with detector time resolutions far too low to resolve coincidence
events.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 09:09:33 GMT"
},
{
"version": "v2",
"created": "Sun, 6 Aug 2006 18:57:37 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Lindenthal",
"Michael",
""
],
[
"Kofler",
"Johannes",
""
]
] |
quant-ph/0606042
|
Jaroslav Rehacek
|
Z. Hradil, D. Mogilevtsev, J. Rehacek
|
Biased tomography schemes: an objective approach
|
4 pages, 3 figures, accepted in PRL
| null |
10.1103/PhysRevLett.96.230401
| null |
quant-ph
| null |
We report on an intrinsic relationship between the maximum-likelihood
quantum-state estimation and the representation of the signal. A quantum
analogy of the transfer function determines the space where the reconstruction
should be done without the need for any ad hoc truncations of the Hilbert
space. An illustration of this method is provided by a simple yet practically
important tomography of an optical signal registered by realistic binary
detectors.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 13:10:43 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Hradil",
"Z.",
""
],
[
"Mogilevtsev",
"D.",
""
],
[
"Rehacek",
"J.",
""
]
] |
quant-ph/0606043
|
Giampiero Esposito Dr.
|
Giuseppe Bimonte, Detlef Born, Enrico Calloni, Giampiero Esposito, Uwe
Hubner, Evgeni Il'ichev, Luigi Rosa, Ornella Scaldaferri, Francesco Tafuri,
Ruggero Vaglio
|
The Aladin2 experiment: sensitivity study
|
4 pages, Latex macros, 10th Conference on Frontier Detectors for
Frontier Physics, Isola D'Elba, 21-27 May 2006
|
Nucl.Instrum.Meth.A572:515-517,2007
|
10.1016/j.nima.2006.10.379
|
DSF preprint 2006/14
|
quant-ph
| null |
Aladin2 is an experiment devoted to the first measurement of variations of
Casimir energy in a rigid body. The main short-term scientific motivation
relies on the possibility of the first demonstration of a phase transition
influenced by vacuum fluctuations while, in the long term and in the mainframe
of the cosmological constant problem, it can be regarded as the first step
towards a measurement of the weight of vacuum energy. In this paper, after a
presentation of the guiding principle of the measurement, the experimental
apparatus and sensitivity studies on final cavities will be presented.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 13:13:20 GMT"
}
] | 2008-11-26T00:00:00 |
[
[
"Bimonte",
"Giuseppe",
""
],
[
"Born",
"Detlef",
""
],
[
"Calloni",
"Enrico",
""
],
[
"Esposito",
"Giampiero",
""
],
[
"Hubner",
"Uwe",
""
],
[
"Il'ichev",
"Evgeni",
""
],
[
"Rosa",
"Luigi",
""
],
[
"Scaldaferri",
"Ornella",
""
],
[
"Tafuri",
"Francesco",
""
],
[
"Vaglio",
"Ruggero",
""
]
] |
quant-ph/0606044
|
Yuri Rostovtsev
|
Yuri V. Rostovtsev, Zoe-Elizabeth Sariyanni, and Marlan O. Scully
|
Electromagnetically induced coherent backscattering
| null | null |
10.1103/PhysRevLett.97.113001
| null |
quant-ph
| null |
We demonstrate a strong coherent backward wave oscillation using forward
propagating fields only. This is achieved by applying laser fields to an
ultra-dispersive medium with proper chosen detunings to excite a molecular
vibrational coherence that corresponds to a backward propagating wave. The
physics then has much in common with propagation of ultra-slow light.
Applications to coherent scattering and remote sensing are discussed.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 13:48:17 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Rostovtsev",
"Yuri V.",
""
],
[
"Sariyanni",
"Zoe-Elizabeth",
""
],
[
"Scully",
"Marlan O.",
""
]
] |
quant-ph/0606045
|
Esteban Guevara Hidalgo
|
Esteban Guevara Hidalgo
|
Quantum Games Entropy
|
6 pages
|
Physica A 383/2, 797-804 (2007)
|
10.1016/j.physa.2007.05.001
| null |
quant-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose the study of quantum games from the point of view of quantum
information theory and statistical mechanics. Every game can be described by a
density operator, the von Neumann entropy and the quantum replicator dynamics.
There exists a strong relationship between game theories, information theories
and statistical physics. The density operator and entropy are the bonds between
these theories. The analysis we propose is based on the properties of entropy,
the amount of information that a player can obtain about his opponent and a
maximum or minimum entropy criterion. The natural trend of a physical system is
to its maximum entropy state. The minimum entropy state is a characteristic of
a manipulated system i.e. externally controlled or imposed. There exist tacit
rules inside a system that do not need to be specified or clarified and search
the system equilibrium under the collective welfare principle. The other rules
are imposed over the system when one or many of its members violate this
principle and maximize its individual welfare at the expense of the group.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 15:00:30 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Oct 2006 16:45:24 GMT"
},
{
"version": "v3",
"created": "Fri, 13 Jul 2007 22:27:32 GMT"
},
{
"version": "v4",
"created": "Thu, 8 Dec 2016 23:01:00 GMT"
}
] | 2016-12-12T00:00:00 |
[
[
"Hidalgo",
"Esteban Guevara",
""
]
] |
quant-ph/0606046
|
Matteo G. A. Paris
|
G. Brida, M. Genovese, M. Gramegna, M. G. A. Paris, E. Predazzi, E.
Cagliero
|
On the reconstruction of diagonal elements of density matrix of quantum
optical states by on/off detectors
|
10 pages, presented at Palermo "TQMFA2005" Conference. To appear on
"Open Systems & Information Dynamics" (2006)
|
Open Syst & Inf Dyn 13 (2006) 333
| null | null |
quant-ph
| null |
We discuss a scheme for reconstructing experimentally the diagonal elements
of the density matrix of quantum optical states. Applications to PDC heralded
photons, multi-thermal and attenuated coherent states are illustrated and
discussed in some details.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 15:49:06 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Brida",
"G.",
""
],
[
"Genovese",
"M.",
""
],
[
"Gramegna",
"M.",
""
],
[
"Paris",
"M. G. A.",
""
],
[
"Predazzi",
"E.",
""
],
[
"Cagliero",
"E.",
""
]
] |
quant-ph/0606047
|
J. G. Muga
|
F. Delgado, A. Ruschhaupt, J. G. Muga
|
Preparation of atomic velocities by bound-state to resonance conversion
| null | null | null | null |
quant-ph
| null |
A procedure is proposed to control the average and width of the velocity
distribution of ultra-cold atoms. The atoms are set initially in a bound state
of an optical trap formed by an inner red detuned laser and an outer blue
detuned laser. The bound state is later converted into a resonance by a
suitable change of the laser intensities. An optimal time dependence of the
switching process, between the sudden and adiabatic limits, adjusts the final
translational energies to the Lorentzian shape of the resonance state.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 17:23:03 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Delgado",
"F.",
""
],
[
"Ruschhaupt",
"A.",
""
],
[
"Muga",
"J. G.",
""
]
] |
quant-ph/0606048
|
Anne Louchet
|
Anne Louchet (LAC), Jamil S. Habib (LAC), Vincent Crozatier (LAC),
Ivan Lorger\'e (LAC), Fabienne Goldfarb (LAC), Fabien Bretenaker (LAC),
Jean-Louis Le Gou\"et (LAC), Olivier Guillot-No\"el (CMCP), Philippe Goldner
(CMCP)
|
Branching ratio measurement of a "Lambda" system in Tm3+:YAG under
magnetic field
| null |
Phys. Rev. B 75, 035131 (2007)
|
10.1103/PhysRevB.75.035131
| null |
quant-ph
| null |
A three-level Lambda system in Tm3+ doped YAG crystal is experimentally
investigated in the prospect of quantum information processing. Zeeman effect
is used to lift the nuclear spin degeneracy of this ion. In a previous paper
[de Seze et al. Phys. Rev. B, 73, 85112 (2006) we measured the gyromagnetic
tensor components and concluded that adequate magnetic field orientation could
optimize the optical connection of both ground state sublevels to each one of
the excited state sublevels, thus generating Lambda systems. Here we report on
the direct measurement of the transition probability ratio along the two legs
of the Lambda. Measurement techniques combine frequency selective optical
pumping with optical nutation or photon echo processes.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 17:32:22 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Dec 2006 13:13:43 GMT"
}
] | 2016-08-16T00:00:00 |
[
[
"Louchet",
"Anne",
"",
"LAC"
],
[
"Habib",
"Jamil S.",
"",
"LAC"
],
[
"Crozatier",
"Vincent",
"",
"LAC"
],
[
"Lorgeré",
"Ivan",
"",
"LAC"
],
[
"Goldfarb",
"Fabienne",
"",
"LAC"
],
[
"Bretenaker",
"Fabien",
"",
"LAC"
],
[
"Gouët",
"Jean-Louis Le",
"",
"LAC"
],
[
"Guillot-Noël",
"Olivier",
"",
"CMCP"
],
[
"Goldner",
"Philippe",
"",
"CMCP"
]
] |
quant-ph/0606049
|
Lluis Masanes
|
Ll. Masanes, R. Renner, M. Christandl, A. Winter, J. Barrett
|
Full security of quantum key distribution from no-signaling constraints
|
15 pages, 2 figure
|
IEEE Transactions on Information Theory, Volume 60, Issue 8, pages
4973-4986, year 2014
|
10.1109/TIT.2014.2329417
| null |
quant-ph cs.CR
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We analyze a cryptographic protocol for generating a distributed secret key
from correlations that violate a Bell inequality by a sufficient amount, and
prove its security against eavesdroppers, constrained only by the assumption
that any information accessible to them must be compatible with the
non-signaling principle. The claim holds with respect to the state-of-the-art
security definition used in cryptography, known as universally-composable
security. The non-signaling assumption only refers to the statistics of
measurement outcomes depending on the choices of measurements; hence security
is independent of the internal workings of the devices --- they do not even
need to follow the laws of quantum theory. This is relevant for practice as a
correct and complete modeling of realistic devices is generally impossible. The
techniques developed are general and can be applied to other Bell
inequality-based protocols. In particular, we provide a scheme for estimating
Bell-inequality violations when the samples are not independent and identically
distributed.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 17:42:34 GMT"
},
{
"version": "v2",
"created": "Mon, 14 Jul 2008 14:01:13 GMT"
},
{
"version": "v3",
"created": "Sun, 27 Jul 2008 08:31:16 GMT"
},
{
"version": "v4",
"created": "Thu, 10 Dec 2009 13:58:31 GMT"
},
{
"version": "v5",
"created": "Wed, 24 Sep 2014 09:54:18 GMT"
}
] | 2014-12-02T00:00:00 |
[
[
"Masanes",
"Ll.",
""
],
[
"Renner",
"R.",
""
],
[
"Christandl",
"M.",
""
],
[
"Winter",
"A.",
""
],
[
"Barrett",
"J.",
""
]
] |
quant-ph/0606050
|
Frederick W. Strauch
|
Frederick W. Strauch
|
Connecting the discrete and continuous-time quantum walks
|
5 pages, 1 figure
|
Phys. Rev. A 74, 030301 (R) (2006)
|
10.1103/PhysRevA.74.030301
| null |
quant-ph
| null |
Recently, quantized versions of random walks have been explored as effective
elements for quantum algorithms. In the simplest case of one dimension, the
theory has remained divided into the discrete-time quantum walk and the
continuous-time quantum walk. Though the properties of these two walks have
shown similarities, it has remained an open problem to find the exact relation
between the two. The precise connection of these two processes, both quantally
and classically, is presented. Extension to higher dimensions is also
discussed.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 19:59:03 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Strauch",
"Frederick W.",
""
]
] |
quant-ph/0606051
|
Xiong-Jun Liu
|
Xiong-Jun Liu, Xin Liu, Zheng-Xin Liu, L. C. Kwek and C. H. Oh
|
Tightly Localized Stationary Pulses in Multi-Level Atomic System
|
5 pages, 3 figures; final version (Fig.3 is revised); to appear in
Phys. Rev. A
|
Phys. Rev. A 75, 023809 (2007)
|
10.1103/PhysRevA.75.023809
| null |
quant-ph
| null |
We show the pulse matching phenomenon can be obtained in the general
multi-level system with electromagnetically induced transparency (EIT). For
this we find a novel way to create tightly localized stationary pulses by using
counter-propagating pump fields. The present process is a spatial compression
of excitation so that it allows us to shape and further intensify the localized
stationary pulses, without using standing waves of pump fields or spatially
modulated pump fields.
|
[
{
"version": "v1",
"created": "Tue, 6 Jun 2006 20:55:47 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Jul 2006 04:46:44 GMT"
},
{
"version": "v3",
"created": "Tue, 26 Sep 2006 09:50:51 GMT"
},
{
"version": "v4",
"created": "Thu, 18 Jan 2007 18:32:39 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Liu",
"Xiong-Jun",
""
],
[
"Liu",
"Xin",
""
],
[
"Liu",
"Zheng-Xin",
""
],
[
"Kwek",
"L. C.",
""
],
[
"Oh",
"C. H.",
""
]
] |
quant-ph/0606052
|
Sergey Yalunin
|
Sergey Yalunin, Sergey B. Leble
|
Multiple scattering and electron-uracil collisions at low energies
|
9 pages, 5 figures
| null |
10.1140/epjst/e2007-00115-x
| null |
quant-ph
| null |
Links between two well known methods: methods of zero-range and
non-overlapped (muffin-tin) potentials are discussed. Some difficulties of the
method of zero-range potentials and its possible elimination are discussed. We
argue that such advanced method of ZRP potential can be applied to realistic
electron-molecular processes. The method reduces electron-molecule scattering
to generalized eigenvalue problem for hermitian matrices and admit fast
numerical scheme. A noteworthy feature of the method is direct possibility to
calculate the wave functions (partial waves). The theory is applied to
electron-uracil scattering. Partial phases and cross-sections at low energies
are evaluated and plotted.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 00:32:32 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Aug 2006 18:41:17 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Yalunin",
"Sergey",
""
],
[
"Leble",
"Sergey B.",
""
]
] |
quant-ph/0606053
|
Ou Yong-Cheng
|
Yong-Cheng Ou and Heng Fan
|
Vanishing environment-induced decoherence
|
4 pages, 2 figures
|
J.Phys.A-Math.Gen. 40,2455(2007)
|
10.1088/1751-8113/40/10/014
| null |
quant-ph
| null |
For a central system uniformly coupled to a XY spin-1/2 bath in a transverse
field, we explicitly calculate the Loschmidt echo(LE) to characterize
decoherence quantitatively. We find that the anisotropy parameter $\gamma $
affects decoherence of the central system sensitively when $\gamma \in [0,1]$%
, in particular, the LE becomes unit without varying with time when $\gamma =0
$, implying that environment-induced decoherence vanishes . Some other cases in
which the LE is unit are discussed also.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 14:00:21 GMT"
},
{
"version": "v2",
"created": "Mon, 7 Aug 2006 13:54:10 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Ou",
"Yong-Cheng",
""
],
[
"Fan",
"Heng",
""
]
] |
quant-ph/0606054
|
Ou Yong-Cheng
|
Yong-Cheng Ou, Zhuang-Qi Cao, and Qi-Shun Shen
|
Formally exact quantization condition for nonrelativistic quantum
systems
|
4 pages. Appeared in Journal of Chemical Physics 121,8175(2004)
|
J.Chem.Phys. 121 (2004) 8175
|
10.1063/1.1799015
| null |
quant-ph astro-ph hep-th
| null |
Based on the standard transfer matrix, a formally exact quantization
condition for arbitrary potentials, which outflanks and unifies the historical
approaches, is derived. It can be used to find the exact bound-state energy
eigenvalues of the quantum system without solving an equation of motion for the
system wave functions.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 05:12:00 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Ou",
"Yong-Cheng",
""
],
[
"Cao",
"Zhuang-Qi",
""
],
[
"Shen",
"Qi-Shun",
""
]
] |
quant-ph/0606055
|
Mikalai Karelin
|
Mikalai Karelin
|
Schmidt number of pure bi-partite entangled states and methods of its
calculation
|
3 pages, 1 figure; based on the poster presentation reported on the
11th International Conference on Quantum Optics (ICQO'2006, Minsk, May 26 --
31, 2006), to be published in special issue of Optics and Spectroscopy
| null |
10.1134/S0030400X07080048
|
Sa27E24
|
quant-ph
| null |
An entanglement measure for pure-state continuous-variable bi-partite
problem, the Schmidt number, is analytically calculated for one simple model of
atom-field scattering.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 06:07:28 GMT"
},
{
"version": "v2",
"created": "Sun, 6 Aug 2006 08:05:33 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Karelin",
"Mikalai",
""
]
] |
quant-ph/0606056
|
Jean Richert
|
Tarek Khalil and Jean Richert
|
Application of a renormalization algorithm in Hilbert space to the study
of many-body quantum systems
|
22 pages, 8 figures
| null | null | null |
quant-ph cond-mat.str-el nucl-th
| null |
We implement an algorithm which is aimed to reduce the number of basis states
spanning the Hilbert space of quantum many-body systems. We test the efficiency
of the procedure by working out and analyzing the spectral properties of
strongly correlated and frustrated quantum spin systems. The role and
importance of symmetries are investigated
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 13:25:40 GMT"
},
{
"version": "v2",
"created": "Thu, 9 Nov 2006 14:07:52 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Khalil",
"Tarek",
""
],
[
"Richert",
"Jean",
""
]
] |
quant-ph/0606057
|
Domenico D'Alessandro
|
Francesca Albertini, Domenico D'Alessandro
|
Analysis and identification of quantum dynamics using Lie algebra
homomorphisms and Cartan decompositions
| null | null | null | null |
quant-ph
| null |
In this paper, we consider the problem of model equivalence for quantum
systems. Two models are said to be (input-output) equivalent if they give the
same output for every admissible input. In the case of quantum systems, the
output is the expectation value of a given observable or, more in general, a
probability distribution for the result of a quantum measurement. We link the
input-output equivalence of two models to the existence of a homomorphism of
the underlying Lie algebra. In several cases, a Cartan decomposition of the Lie
algebra su(n) is useful to find such a homomorphism and to determine the
classes of equivalent models. We consider in detail the important cases of two
level systems with a Cartan structure and of spin networks. In the latter case,
complete results are given generalizing previous results to the case of
networks of spin particles with any value of the spin. In treating this
problem, we prove some instrumental results on the subalgebras of su(n) which
are of independent interest.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 10:04:42 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Albertini",
"Francesca",
""
],
[
"D'Alessandro",
"Domenico",
""
]
] |
quant-ph/0606058
|
Jeroen Vandenbrink
|
Jasper van Wezel and Jeroen van den Brink
|
Limit to manipulation of qubits due to spontaneous symmetry breaking
|
2 pages, proceedings, to appear in JMMM
|
Journal of Magnetism and Magnetic Materials 310, e503 (2007).
|
10.1016/j.jmmm.2006.10.623
| null |
quant-ph cond-mat.stat-mech cond-mat.str-el
| null |
We consider a two-spin qubit that is subject to the orderparameter field of a
symmetry broken manipulation device. It is shown that the thin spectrum of the
manipulation device limits the coherence of the qubit.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 13:22:04 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"van Wezel",
"Jasper",
""
],
[
"Brink",
"Jeroen van den",
""
]
] |
quant-ph/0606059
|
Michael Reimpell
|
M. Reimpell, R. F. Werner and K. Audenaert
|
Comment on "Optimum Quantum Error Recovery using Semidefinite
Programming"
|
2 pages, 1 figure
| null | null | null |
quant-ph
| null |
In a recent paper ([1]=quant-ph/0606035) it is shown how the optimal recovery
operation in an error correction scheme can be considered as a semidefinite
program. As a possible future improvement it is noted that still better error
correction might be obtained by optimizing the encoding as well. In this note
we present the result of such an improvement, specifically for the four-bit
correction of an amplitude damping channel considered in [1]. We get a strict
improvement for almost all values of the damping parameter. The method (and the
computer code) is taken from our earlier study of such correction schemes
(quant-ph/0307138).
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 15:24:55 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Reimpell",
"M.",
""
],
[
"Werner",
"R. F.",
""
],
[
"Audenaert",
"K.",
""
]
] |
quant-ph/0606060
|
Kurt Jacobs
|
Kurt Jacobs and Pavel Lougovski
|
Emergent Quantum Jumps in a Nano-Electro-Mechanical System
|
7 pages, revtex4, 1 eps figure. v2 and v3: presentation altered,
references added
|
J. Phys. A: Math. Theor. 40, F987 (2007)
|
10.1088/1751-8113/40/46/F02
| null |
quant-ph cond-mat.mes-hall
| null |
We describe a nano-electromechnical system that exhibits the "retroactive"
quantum jumps discovered by Mabuchi and Wiseman [Phys. Rev. Lett. 81, 4620
(1998)]. This system consists of a Cooper-pair box coupled to a nano-mechanical
resonator, in which the latter is continuously monitored by a single-electron
transistor or quantum point-contact. Further, we show that these kinds of
jumps, and the jumps that emerge in a continuous quantum non-demolition
measurement are one and the same phenomena. We also consider manipulating the
jumps by applying feedback control to the Cooper-pair box.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 18:41:16 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Jun 2006 22:33:35 GMT"
},
{
"version": "v3",
"created": "Tue, 23 Oct 2007 16:35:43 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Jacobs",
"Kurt",
""
],
[
"Lougovski",
"Pavel",
""
]
] |
quant-ph/0606061
|
Robert R. Tucci
|
Robert R. Tucci
|
Simplifying Quantum Circuits via Circuit Invariants and Dressed CNOTs
|
71 pages (59 files: 1 .tex, 2 .sty, 18 .eps, 37 .m, 1 .xxx)ArXiv
generates a pdf with mangled Table of Contents, my software doesn't. If this
bothers you, download source from ArXiv and recompile at home
| null | null | null |
quant-ph
| null |
Quantum Compiling Algorithms decompose (exactly, without approximations) an
arbitrary $2^\nb$ unitary matrix acting on $\nb$ qubits, into a sequence of
elementary operations (SEO). There are many possible ways of decomposing a
unitary matrix into a SEO, and some of these decompositions have shorter length
(are more efficient) than others. Finding an optimum (shortest) decomposition
is a very hard task, and is not our intention here. A less ambitious, more
doable task is to find methods for optimizing small segments of a SEO. Call
these methods piecewise optimizations. Piecewise optimizations involve
replacing a small quantum circuit by an equivalent one with fewer CNOTs. Two
circuits are said to be equivalent if one of them multiplied by some external
local operations equals the other. This equivalence relation between circuits
has its own class functions, which we call circuit invariants. Dressed CNOTs
are a simple yet very useful generalization of standard CNOTs. After discussing
circuit invariants and dressed CNOTs, we give some methods for simplifying
2-qubit and 3-qubit circuits. We include with this paper software (written in
Octave/Matlab) that checks many of the algorithms proposed in the paper.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 18:41:49 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Tucci",
"Robert R.",
""
]
] |
quant-ph/0606062
|
Kevin Moore
|
Kevin L. Moore, Subhadeep Gupta, Kater W. Murch, and Dan M.
Stamper-Kurn
|
Probing the quantum state of a guided atom laser pulse
|
4 pages, 3 figures
| null |
10.1103/PhysRevLett.97.180410
| null |
quant-ph cond-mat.soft
| null |
We describe bichromatic superradiant pump-probe spectroscopy as a tomographic
probe of the Wigner function of a dispersing particle beam. We employed this
technique to characterize the quantum state of an ultracold atomic beam,
derived from a Rb-87 Bose-Einstein condensate, as it propagated in a 2.5 mm
diameter circular waveguide. Our measurements place an upper bound on the
longitudinal phase-space area occupied by the 300,000 atom beam of 9(1) $\hbar$
and a lower bound on the coherence length (L > 13 microns). These results are
consistent with full quantum degeneracy after multiple orbits around the
waveguide.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 19:29:33 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Moore",
"Kevin L.",
""
],
[
"Gupta",
"Subhadeep",
""
],
[
"Murch",
"Kater W.",
""
],
[
"Stamper-Kurn",
"Dan M.",
""
]
] |
quant-ph/0606063
|
James Malley
|
James D. Malley
|
The Collapse of Bell Determinism
|
accepted for publication in Physics Letters A; expanded abstract;
typos corrected
| null |
10.1016/j.physleta.2006.06.022
| null |
quant-ph
| null |
The Bell-Kochen-Specker conditions (BKS) for a deterministic noncontextual
hidden-variable model are wonderfully simple to state, deal with just
one-dimensional projectors on a Hilbert space H and make no reference to a
probabilistic phase space or quantum system. They only ask for an assignment of
zero or one to every projector such that the assignment respects orthogonal
resolutions of the identity. Various no-go results in the literature show that
the pair of statements {BKS is valid; dim H greater than or equal to 3} are
inconsistent. Here we show, more radically, that the pair actually contradicts
the dimensionality of the space itself, by implying that there can exist at
most a single one-dimensional projector acting on H. Our derivation involves
only elementary inner product spaces. It is non-probabilistic, inequality-free,
state independent, does not use entanglement, and is simultaneously valid in
all dimensions three or greater.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 20:28:07 GMT"
},
{
"version": "v2",
"created": "Mon, 19 Jun 2006 18:57:11 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Malley",
"James D.",
""
]
] |
quant-ph/0606064
|
Robert Kosut
|
Robert L. Kosut, Matthew Grace, Constantin Brif, Herschel Rabitz
|
On the distance between unitary propagators of quantum systems of
differing dimensions
|
8 pages
| null | null | null |
quant-ph
| null |
A distance measure is presented between two unitary propagators of quantum
systems of differing dimensions along with a corresponding method of
computation. A typical application is to compare the propagator of the actual
(real) process with the propagator of the desired (ideal) process; the former
being of a higher dimension then the latter. The proposed measure has the
advantage of dealing with possibly correlated inputs, but at the expense of
working on the whole space and not just the information bearing part as is
usually the case, i.e., no partial trace operation is explicitly involved. It
is also shown that the distance measure and an average measure of channel
fidelity both depend on the size of the same matrix: as the matrix size
increases, distance decreases and fidelity increases.
|
[
{
"version": "v1",
"created": "Wed, 7 Jun 2006 22:43:36 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Kosut",
"Robert L.",
""
],
[
"Grace",
"Matthew",
""
],
[
"Brif",
"Constantin",
""
],
[
"Rabitz",
"Herschel",
""
]
] |
quant-ph/0606065
|
David Feder
|
David L. Feder
|
Perfect quantum state transfer with spinor bosons on weighted graphs
|
4 pages, 2 figures, revtex
|
Phys. Rev. Lett. 97, 180502 (2006)
|
10.1103/PhysRevLett.97.180502
| null |
quant-ph cond-mat.other
| null |
A duality between the properties of many spinor bosons on a regular lattice
and those of a single particle on a weighted graph reveals that a quantum
particle can traverse an infinite hierarchy of networks with perfect
probability in polynomial time, even as the number of nodes increases
exponentially. The one-dimensional `quantum wire' and the hypercube are special
cases in this construction, where the number of spin degrees of freedom is
equal to one and the number of particles, respectively. An implementation of
near-perfect quantum state transfer across a weighted parallelepiped with
ultracold atoms in optical lattices is discussed.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 03:39:59 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Feder",
"David L.",
""
]
] |
quant-ph/0606066
|
Francois Le Gall
|
Francois Le Gall
|
Exponential Separation of Quantum and Classical Online Space Complexity
|
13 pages. v3: minor changes
|
Theory of Computing Systems 45(2): 188-202 (2009)
|
10.1007/s00224-007-9097-3
| null |
quant-ph cs.CC
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Although quantum algorithms realizing an exponential time speed-up over the
best known classical algorithms exist, no quantum algorithm is known performing
computation using less space resources than classical algorithms. In this
paper, we study, for the first time explicitly, space-bounded quantum
algorithms for computational problems where the input is given not as a whole,
but bit by bit. We show that there exist such problems that a quantum computer
can solve using exponentially less work space than a classical computer. More
precisely, we introduce a very natural and simple model of a space-bounded
quantum online machine and prove an exponential separation of classical and
quantum online space complexity, in the bounded-error setting and for a total
language. The language we consider is inspired by a communication problem (the
set intersection function) that Buhrman, Cleve and Wigderson used to show an
almost quadratic separation of quantum and classical bounded-error
communication complexity. We prove that, in the framework of online space
complexity, the separation becomes exponential.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 04:27:30 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Dec 2006 08:16:34 GMT"
},
{
"version": "v3",
"created": "Tue, 11 Nov 2008 06:35:49 GMT"
}
] | 2009-06-18T00:00:00 |
[
[
"Gall",
"Francois Le",
""
]
] |
quant-ph/0606067
|
Tamar Ravon
|
Tamar Ravon, Lev Vaidman
|
The Three-Box Paradox Revisited
|
13 pages, 4 figures
| null |
10.1088/1751-8113/40/11/021
| null |
quant-ph
| null |
The classical three-box paradox of Kirkpatrick [J. Phys. A 36 4891 (2003)] is
compared to the original quantum Three-Box paradox of Aharonov and Vaidman [J.
Phys. A 24 2315 (1991)]. It is argued that the quantum Three-Box experiment is
a "quantum paradox" in the sense that it is an example of a classical task
which cannot be accomplished using classical means, but can be accomplished
using quantum devices. It is shown that Kirkpatrick's card game is analogous to
a different game with a particle in three boxes which does not contain
paradoxical features.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 07:46:23 GMT"
},
{
"version": "v2",
"created": "Sun, 6 Aug 2006 16:24:07 GMT"
}
] | 2015-06-26T00:00:00 |
[
[
"Ravon",
"Tamar",
""
],
[
"Vaidman",
"Lev",
""
]
] |
quant-ph/0606068
|
Eric Charron
|
Eric Charron (PPM), Maurice Raoult (LAC)
|
Phase information revealed by interferences in the ionization of
rotational wave packets
| null |
Physical Review A / Physical Review A (General Physics); Phys Rev
A Gen Phys; Physical Review A (Atomic Molecular and Optical Physics) 74, 3
(15/09/2006) 033407
|
10.1103/PhysRevA.74.033407
| null |
quant-ph physics.chem-ph
| null |
Time-resolved photoelectron spectra are proposed for the measurement of
classical information recorded in the quantum phases of a molecular rotational
wave packet. Taking Li2 as a prototypical system, we show that an interference
arises from the electron-nuclei entanglement induced by the molecular
anisotropy. This phenomenon is used to transfer the information that was stored
initially in the nuclear rotational degree of freedom into the electronic
degree of freedom.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 10:00:28 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Jul 2006 11:56:08 GMT"
},
{
"version": "v3",
"created": "Sat, 26 Aug 2006 07:47:43 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Charron",
"Eric",
"",
"PPM"
],
[
"Raoult",
"Maurice",
"",
"LAC"
]
] |
quant-ph/0606069
|
Alexandre Matzkin
|
M Lombardi and A Matzkin
|
Dynamical entanglement and chaos: the case of Rydberg molecules
| null |
Phys. Rev. A 73, 062335 (2006)
|
10.1103/PhysRevA.73.062335
| null |
quant-ph
| null |
A Rydberg molecule is composed of an outer electron that collides on the
residual ionic core. Typical states of Rydberg molecules display entanglement
between the outer electron and the core. In this work we quantify the average
entanglement of molecular eigenstates and further investigate the time
evolution of entanglement production from initially unentangled states. The
results are contrasted with the underlying classical dynamics, obtained from
the semiclassical limit of the core-electron collision. Our findings indicate
that entanglement is not simply correlated with the degree of classical chaos,
but rather depends on the specific phase-space features that give rise to
inelastic scattering. Hence mixed phase-space or even regular classical
dynamics can be associated with high entanglement generation.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 10:10:17 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Lombardi",
"M",
""
],
[
"Matzkin",
"A",
""
]
] |
quant-ph/0606070
|
Frieder Kleefeld
|
F. Kleefeld (CFIF, IST, Lisbon, Portugal)
|
On some meaningful inner product for real Klein-Gordon fields with
positive semi-definite norm
|
8 pages, no figures; correction of obvious typos and marginal
improvement of formulations
|
Czech.J.Phys.56:999-1006,2006
|
10.1007/s10582-006-0395-9
|
FK-2006-3
|
quant-ph hep-ph hep-th
| null |
A simple derivation of a meaningful, manifestly covariant inner product for
real Klein-Gordon (KG) fields with positive semi-definite norm is provided
which turns out - assuming a symmetric bilinear form - to be the real-KG-field
limit of the inner product for complex KG fields reviewed by A. Mostafazadeh
and F. Zamani in December, 2003, and February, 2006 (quant-ph/0312078,
quant-ph/0602151, quant-ph/0602161). It is explicitly shown that the positive
semi-definite norm associated with the derived inner product for real KG fields
measures the number of active positive and negative energy Fourier modes of the
real KG field on the relativistic mass shell. The very existence of an inner
product with positive semi-definite norm for the considered real, i.e. neutral,
KG fields shows that the metric operator entering the inner product does not
contain the charge-conjugation operator. This observation sheds some additional
light on the meaning of the C operator in the CPT inner product of PT-symmetric
Quantum Mechanics defined by C.M. Bender, D.C. Brody and H.F. Jones.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 10:56:40 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Jun 2006 18:30:52 GMT"
}
] | 2008-11-26T00:00:00 |
[
[
"Kleefeld",
"F.",
"",
"CFIF, IST, Lisbon, Portugal"
]
] |
quant-ph/0606071
|
Jens Siewert
|
Robert Lohmayer, Andreas Osterloh, Jens Siewert, Armin Uhlmann
|
Entangled three-qubit states without concurrence and three-tangle
|
10 RevTeX pages, 3 figures, abstract and conclusions substantially
extended
|
Phys. Rev. Lett. 97, 260502 (2006)
|
10.1103/PhysRevLett.97.260502
| null |
quant-ph
| null |
We provide a complete analysis of mixed three-qubit states composed of a GHZ
state and a W state orthogonal to the former. We present optimal decompositions
and convex roofs for the three-tangle. Further, we provide an analytical method
to decide whether or not an arbitrary rank-2 state of three qubits has
vanishing three-tangle. These results highlight intriguing differences compared
to the properties of two-qubit mixed states, and may serve as a quantitative
reference for future studies of entanglement in multipartite mixed states. By
studying the Coffman-Kundu-Wootters inequality we find that, while the amounts
of inequivalent entanglement types strictly add up for pure states, this
``monogamy'' can be lifted for mixed states by virtue of vanishing tangle
measures.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 12:10:48 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Sep 2006 16:48:21 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Lohmayer",
"Robert",
""
],
[
"Osterloh",
"Andreas",
""
],
[
"Siewert",
"Jens",
""
],
[
"Uhlmann",
"Armin",
""
]
] |
quant-ph/0606072
|
Ivan Marcikic
|
Ivan Marcikic, Antia Lamas-Linares and Christian Kurtsiefer
|
Free-space quantum key distribution with entangled photons
|
3 pages, 2 figures, reviewed version, accepted in Applied Physics
Letters
|
Appl. Phys. Lett. 89, 101122 (2006)
|
10.1063/1.2348775
| null |
quant-ph
| null |
We report on a complete experimental implementation of a quantum key
distribution protocol through a free space link using polarization-entangled
photon pairs from a compact parametric down-conversion source. Over 10 hours of
uninterrupted communication between sites 1.5 km apart, we observe average key
generation rates of 630 per second after error correction and privacy
amplification. Our scheme requires no specific hardware channel for
synchronization apart from a classical wireless link, and no explicit random
number generator.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 12:55:40 GMT"
},
{
"version": "v2",
"created": "Thu, 3 Aug 2006 02:37:06 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Marcikic",
"Ivan",
""
],
[
"Lamas-Linares",
"Antia",
""
],
[
"Kurtsiefer",
"Christian",
""
]
] |
quant-ph/0606073
|
Dirk Seidel
|
D. Seidel, J.G. Muga
|
Ramsey interferometry with oppositely detuned fields
|
6 pages, 6 figures
| null |
10.1103/PhysRevA.75.023811
| null |
quant-ph
| null |
We report a narrowing of the interference pattern obtained in an atomic
Ramsey interferometer if the two separated fields have different frequency and
their phase difference is controlled. The width of the Ramsey fringes depends
inversely on the free flight time of ground state atoms before entering the
first field region in addition to the time between the fields. The effect is
stable also for atomic wavepackets with initial position and momentum
distributions and for realistic mode functions.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 13:36:30 GMT"
}
] | 2013-05-29T00:00:00 |
[
[
"Seidel",
"D.",
""
],
[
"Muga",
"J. G.",
""
]
] |
quant-ph/0606074
|
Giuliano Benenti
|
Davide Rossini, Giuliano Benenti, Giulio Casati
|
Conservative chaotic map as a model of quantum many-body environment
|
8 pages, 4 figures
|
Phys. Rev. E 74, 036209 (2006)
|
10.1103/PhysRevE.74.036209
| null |
quant-ph cond-mat.stat-mech nlin.CD
| null |
We study the dynamics of the entanglement between two qubits coupled to a
common chaotic environment, described by the quantum kicked rotator model. We
show that the kicked rotator, which is a single-particle deterministic
dynamical system, can reproduce the effects of a pure dephasing many-body bath.
Indeed, in the semiclassical limit the interaction with the kicked rotator can
be described as a random phase-kick, so that decoherence is induced in the
two-qubit system. We also show that our model can efficiently simulate
non-Markovian environments.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 15:09:33 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Rossini",
"Davide",
""
],
[
"Benenti",
"Giuliano",
""
],
[
"Casati",
"Giulio",
""
]
] |
quant-ph/0606075
|
Mehdi Mirzaee
|
M. A. Jafarizadeh, M.Mirzaee, M.Rezaee
|
Best separable approximation with semi-definite programming method
|
23 pages
| null | null | null |
quant-ph
| null |
The present methods for obtaining the optimal Lewenestein- Sanpera
decomposition of a mixed state are difficult to handle analytically. We provide
a simple analytical expression for the optimal Lewenstein-Sanpera decomposition
by using semidefinite programming. Specially, we obtain the optimal
Lewenstein-Sanpera decomposition for some examples such as: Bell decomposable
state, Iso-concurrence state, generic two qubit state in Wootters's basis,
$2\otimes 3$ Bell decomposable state, $d\otimes d$ Werner and isotropic states,
a one parameter $3\otimes 3$ state and finally multi partite isotropic state.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 14:57:44 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Jafarizadeh",
"M. A.",
""
],
[
"Mirzaee",
"M.",
""
],
[
"Rezaee",
"M.",
""
]
] |
quant-ph/0606076
|
Jacob Sherson
|
Jacob F. Sherson and Klaus Molmer
|
Polarization squeezing by optical Faraday rotation
|
4 pages, 4 figures
|
Phys. Rev. Lett. 97, 143602 (2006)
|
10.1103/PhysRevLett.97.143602
| null |
quant-ph
| null |
We show that it is possible to generate continuous-wave fields and pulses of
polarization squeezed light by sending classical, linearly polarized laser
light twice through an atomic sample which causes an optical Faraday rotation
of the field polarization. We characterize the performance of the process, and
we show that an appreciable degree of squeezing can be obtained under realistic
physical assumptions.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 15:09:31 GMT"
}
] | 2011-10-13T00:00:00 |
[
[
"Sherson",
"Jacob F.",
""
],
[
"Molmer",
"Klaus",
""
]
] |
quant-ph/0606077
|
Attila Nagy
|
Attila B. Nagy
|
On an implementation of the Solovay-Kitaev algorithm
|
10 pages, published on the 10th Rhine Workshop on Computer Algebra
| null | null | null |
quant-ph
| null |
In quantum computation we are given a finite set of gates and we have to
perform a desired operation as a product of them. The corresponding
computational problem is approximating an arbitrary unitary as a product in a
topological generating set of $SU(d)$. The problem is known to be solvable in
time $polylog(1/\epsilon)$ with product length $polylog(1/\epsilon)$, where the
implicit constants depend on the given generators. The existing algorithms
solve the problem but they need a very slow and space consuming preparatory
stage. This stage runs in time exponential in $d^2$ and requires memory of size
exponential in $d^2$. In this paper we present methods which make the
implementation of the existing algorithms easier. We present heuristic methods
which make a time-length trade-off in the preparatory step. We decrease the
running time and the used memory to polynomial in $d$ but the length of the
products approximating the desired operations will increase (by a factor which
depends on $d$). We also present a simple method which can be used for
decomposing a unitary into a product of group commutators for $2<d<256$, which
is an important part of the existing algorithm.
|
[
{
"version": "v1",
"created": "Thu, 8 Jun 2006 16:09:58 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Nagy",
"Attila B.",
""
]
] |
quant-ph/0606078
|
Robert Kosut
|
Robert L. Kosut and Daniel A. Lidar
|
Quantum Error Correction via Convex Optimization
|
16 pages
|
Quant. Inf. Proc. 8, 443 (2009)
|
10.1007/s11128-009-0120-2
| null |
quant-ph
| null |
We show that the problem of designing a quantum information error correcting
procedure can be cast as a bi-convex optimization problem, iterating between
encoding and recovery, each being a semidefinite program. For a given encoding
operator the problem is convex in the recovery operator. For a given method of
recovery, the problem is convex in the encoding scheme. This allows us to
derive new codes that are locally optimal. We present examples of such codes
that can handle errors which are too strong for codes derived by analogy to
classical error correction techniques.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 06:40:14 GMT"
}
] | 2009-10-16T00:00:00 |
[
[
"Kosut",
"Robert L.",
""
],
[
"Lidar",
"Daniel A.",
""
]
] |
quant-ph/0606079
|
Kevin Birnbaum
|
K. M. Birnbaum, A. S. Parkins, H. J. Kimble
|
Cavity QED with Multiple Hyperfine Levels
|
6 pages, 10 figures
| null |
10.1103/PhysRevA.74.063802
| null |
quant-ph
| null |
We calculate the weak-driving transmission of a linearly polarized cavity
mode strongly coupled to the D2 transition of a single Cesium atom. Results are
relevant to future experiments with microtoroid cavities, where the
single-photon Rabi frequency g exceeds the excited-state hyperfine splittings,
and photonic bandgap resonators, where g is greater than both the excited- and
ground-state splitting.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 02:13:34 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Birnbaum",
"K. M.",
""
],
[
"Parkins",
"A. S.",
""
],
[
"Kimble",
"H. J.",
""
]
] |
quant-ph/0606080
|
Hassan Safari
|
Hassan Safari, Stefan Yoshi Buhmann, Dirk-Gunnar Welsch, and Ho Trung
Dung
|
Body-assisted van der Waals interaction between two atoms
|
17 pages, 9 figures
|
Physical Review A 74 (4), 042101 (2006)
|
10.1103/PhysRevA.74.042101
| null |
quant-ph
| null |
Using fourth-order perturbation theory, a general formula for the van der
Waals potential of two neutral, unpolarized, ground-state atoms in the presence
of an arbitrary arrangement of dispersing and absorbing magnetodielectric
bodies is derived. The theory is applied to two atoms in bulk material and in
front of a planar multilayer system, with special emphasis on the cases of a
perfectly reflecting plate and a semi-infinite half space. It is demonstrated
that the enhancement and reduction of the two-atom interaction due to the
presence of a perfectly reflecting plate can be understood, at least in the
nonretarded limit, by using the method of image charges. For the semi-infinite
half space, both analytical and numerical results are presented.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 13:47:11 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Safari",
"Hassan",
""
],
[
"Buhmann",
"Stefan Yoshi",
""
],
[
"Welsch",
"Dirk-Gunnar",
""
],
[
"Dung",
"Ho Trung",
""
]
] |
quant-ph/0606081
|
Eyal Buks
|
Eyal Buks and Bernard Yurke
|
Mass Detection with Nonlinear Nanomechanical Resonator
| null | null |
10.1103/PhysRevE.74.046619
| null |
quant-ph cond-mat.mes-hall nlin.SI
| null |
Nanomechanical resonators having small mass, high resonance frequency and low
damping rate are widely employed as mass detectors. We study the performances
of such a detector when the resonator is driven into a region of nonlinear
oscillations. We predict theoretically that in this region the system acts as a
phase-sensitive mechanical amplifier. This behavior can be exploited to achieve
noise squeezing in the output signal when homodyne detection is employed for
readout. We show that mass sensitivity of the device in this region may exceed
the upper bound imposed by thermomechanical noise upon the sensitivity when
operating in the linear region. On the other hand, we show that the high mass
sensitivity is accompanied by a slowing down of the response of the system to a
change in the mass.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 10:35:59 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Jun 2006 07:03:30 GMT"
},
{
"version": "v3",
"created": "Thu, 15 Jun 2006 07:44:48 GMT"
},
{
"version": "v4",
"created": "Wed, 5 Jul 2006 07:31:16 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Buks",
"Eyal",
""
],
[
"Yurke",
"Bernard",
""
]
] |
quant-ph/0606082
|
Philipp Treutlein
|
Philipp Treutlein, Theodor W. H\"ansch, Jakob Reichel, Antonio
Negretti, Markus A. Cirone, Tommaso Calarco
|
Microwave potentials and optimal control for robust quantum gates on an
atom chip
|
14 pages, 7 figures, 1 table. Published version (minor changes)
|
Phys. Rev. A 74, 022312 (2006)
|
10.1103/PhysRevA.74.022312
| null |
quant-ph
| null |
We propose a two-qubit collisional phase gate that can be implemented with
available atom chip technology, and present a detailed theoretical analysis of
its performance. The gate is based on earlier phase gate schemes, but uses a
qubit state pair with an experimentally demonstrated, very long coherence
lifetime. Microwave near-fields play a key role in our implementation as a
means to realize the state-dependent potentials required for conditional
dynamics. Quantum control algorithms are used to optimize gate performance. We
employ circuit configurations that can be built with current fabrication
processes, and extensively discuss the impact of technical noise and
imperfections that characterize an actual atom chip. We find an overall
infidelity compatible with requirements for fault-tolerant quantum computation.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 10:48:11 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Aug 2006 18:18:26 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Treutlein",
"Philipp",
""
],
[
"Hänsch",
"Theodor W.",
""
],
[
"Reichel",
"Jakob",
""
],
[
"Negretti",
"Antonio",
""
],
[
"Cirone",
"Markus A.",
""
],
[
"Calarco",
"Tommaso",
""
]
] |
quant-ph/0606083
|
Beatrix Hiesmayr C.
|
Bernhard Baumgartner, Beatrix C. Hiesmayr and Heide Narnhofer
|
The state space for two qutrits has a phase space structure in its core
|
3 figures
|
Phys. Rev. A 74, 032327 (2006)
|
10.1103/PhysRevA.74.032327
| null |
quant-ph
| null |
We investigate the state space of bipartite qutrits. For states which are
locally maximally mixed we obtain an analog of the ``magic'' tetrahedron for
bipartite qubits--a magic simplex W. This is obtained via the Weyl group which
is a kind of ``quantization'' of classical phase space. We analyze how this
simplex W is embedded in the whole state space of two qutrits and discuss
symmetries and equivalences inside the simplex W. Because we are explicitly
able to construct optimal entanglement witnesses we obtain the border between
separable and entangled states. With our method we find also the total area of
bound entangled states of the parameter subspace under intervestigation. Our
considerations can also be applied to higher dimensions.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 11:00:34 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Baumgartner",
"Bernhard",
""
],
[
"Hiesmayr",
"Beatrix C.",
""
],
[
"Narnhofer",
"Heide",
""
]
] |
quant-ph/0606084
|
Travis Norsen
|
Travis Norsen
|
Counter-Factual Meaningfulness and the Bell and CHSH Inequalities
| null | null | null | null |
quant-ph
| null |
We discuss the role of counter-factual meaningfulness (a weaker cousin of
"counter-factual definiteness") as a premise in the derivation of the Bell and
CHSH inequalities. The basic question motivating the discussion is this: can
the CHSH inequality, unlike the original Bell inequality, be derived without
making a hidden-variables (or equivalent counter-factual definiteness)
assumption? We answer, somewhat tentatively, in the negative, and suggest that
an appropriately-modified version of the EPR argument is needed to rigorously
establish that the empirical violation of Bell-type inequalities can only be
blamed on the failure, in nature, of local causality.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 11:26:25 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Norsen",
"Travis",
""
]
] |
quant-ph/0606085
|
Mikael Lassen
|
Mikael Lassen (DTU, ACQAO), Vincent Delaubert (LKB - Jussieu, ACQAO),
Charles C. Harb (ACQAO), Nicolas Treps (LKB - Jussieu), Ping Koy Lam (ACQAO),
Hans A. Bachor (ACQAO)
|
Generation of Squeezing in Higher Order Hermite-Gaussian Modes with an
Optical Parametric Amplifier
|
7 pages, 4 figures
|
Journal of the European Optical Society - Rapid Publications 1,
06003 (2006)
|
10.2971/jeos.2006.06003
| null |
quant-ph
| null |
We demonstrate quantum correlations in the transverse plane of continuous
wave light beams by producing -4.0 dB, -2.6 dB and -1.5 dB of squeezing in the
TEM00, TEM10 and TEM20 Hermite- Gauss modes with an optical parametric
amplifier, respectively. This has potential applications in quantum information
networking, enabling parallel quantum information processing. We describe the
setup for the generation of squeezing and analyze the effects of various
experimental issues such as mode overlap between pump and seed and nonlinear
losses.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 12:24:01 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Lassen",
"Mikael",
"",
"DTU, ACQAO"
],
[
"Delaubert",
"Vincent",
"",
"LKB - Jussieu, ACQAO"
],
[
"Harb",
"Charles C.",
"",
"ACQAO"
],
[
"Treps",
"Nicolas",
"",
"LKB - Jussieu"
],
[
"Lam",
"Ping Koy",
"",
"ACQAO"
],
[
"Bachor",
"Hans A.",
"",
"ACQAO"
]
] |
quant-ph/0606086
|
Luis Roa Oppliger
|
L. Roa, G. A. Olivares-Renteria, M. L. L. de Guevara, A. Delgado
|
Measurement-driven quantum evolution from a known state
| null | null | null | null |
quant-ph
| null |
We study the problem of driving a known initial quantum state onto a known
pure state without using a unitary evolution. This task can be achieved by
means of von Neumann measurement processes, introducing N observables which are
consecutively measured in order to approach the state of the system to the
target state. We proved that the probability of projecting onto the target
state can be increased meaningfully by adding suitable observables to the
process, that is, it converges to 1 when N increases. We also discuss a
physical implementation of this scheme.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 12:29:59 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Jun 2006 15:47:24 GMT"
}
] | 2007-05-23T00:00:00 |
[
[
"Roa",
"L.",
""
],
[
"Olivares-Renteria",
"G. A.",
""
],
[
"de Guevara",
"M. L. L.",
""
],
[
"Delgado",
"A.",
""
]
] |
quant-ph/0606087
|
Jaewoo Joo
|
Jaewoo Joo, P. L. Knight, and Jiannis K. Pachos
|
Single atom quantum walk with 1D optical superlattices
|
6 pages, 7 figures
| null |
10.1080/09500340601110584
| null |
quant-ph
| null |
A proposal for the implementation of quantum walks using cold atom technology
is presented. It consists of one atom trapped in time varying optical
superlattices. The required elements are presented in detail including the
preparation procedure, the manipulation required for the quantum walk evolution
and the final measurement. These procedures can be, in principle, implemented
with present technology.
|
[
{
"version": "v1",
"created": "Fri, 9 Jun 2006 14:54:05 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Jun 2006 09:29:43 GMT"
}
] | 2009-11-13T00:00:00 |
[
[
"Joo",
"Jaewoo",
""
],
[
"Knight",
"P. L.",
""
],
[
"Pachos",
"Jiannis K.",
""
]
] |
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