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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9604011 | David Meyer | David A. Meyer | On the absence of homogeneous scalar unitary cellular automata | 7 pages, plain TeX, 3 PostScript figures included with epsf.tex
(ignore the under/overfull \vbox error messages); minor changes (including
title wording) in response to referee suggestions, also updated references;
to appear in Phys. Lett. A | null | 10.1016/S0375-9601(96)00745-1 | null | quant-ph comp-gas hep-th nlin.CG | null | Failure to find homogeneous scalar unitary cellular automata (CA) in one
dimension led to consideration of only ``approximately unitary'' CA---which
motivated our recent proof of a No-go Lemma in one dimension. In this note we
extend the one dimensional result to prove the absence of nontrivial
homogeneous scalar unitary CA on Euclidean lattices in any dimension.
| [
{
"version": "v1",
"created": "Fri, 12 Apr 1996 05:27:40 GMT"
},
{
"version": "v2",
"created": "Fri, 25 Oct 1996 23:20:48 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Meyer",
"David A.",
""
]
] |
quant-ph/9604012 | Madina Penntinen | M. Penttinen | Small-angle scattering on a system of magnetic and electric charges | 15 pages. 3 figures. Latex with epsf.sty used | Int.J.Mod.Phys. A12 (1997) 3193-3204 | 10.1142/S0217751X97001687 | RUB-TPII-02/96 | quant-ph hep-ph hep-th | null | The generalization of the conformal scattering method for small-angle
scattering processes involving magnetic monopoles and ordinary charges is
constructed. Using this generalization we show that introducing of magnetic
charges corresponds to analytical continuation of the eikonal amplitude in the
complex charge plane (the imaginary part is proportional to the magnetic
charge). We calculate explicitly the eikonal amplitude for scattering on a dyon
and two monopoles in terms of confluent hypergeometric functions. The
singularities of the corresponding amplitudes (focal points) are studied in
details.
| [
{
"version": "v1",
"created": "Mon, 15 Apr 1996 15:20:57 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Penttinen",
"M.",
""
]
] |
quant-ph/9604013 | P. Busch | P. Busch (U. Hull) and A. Shimony (Boston University) | Insolubility of the Quantum Measurement Problem for Unsharp Observables | plain TeX, 10 pages | Stud. Hist. Phil. Mod. Phys. 27 (1996) 397-404. | null | null | quant-ph | null | The quantum mechanical measurement problem is the difficulty of dealing with
the indefiniteness of the pointer observable at the conclusion of a measurement
process governed by unitary quantum dynamics. There has been hope to solve this
problem by eliminating idealizations from the characterization of measurement.
We state and prove two `insolubility theorems' that disappoint this hope. In
both the initial state of the apparatus is taken to be mixed rather than pure,
and the correlation of the object observable and the pointer observable is
allowed to be imperfect. In the {\it insolubility theorem for sharp
observables}, which is only a modest extension of previous results, the object
observable is taken to be an arbitrary projection valued measure. In the {\it
insolubility theorem for unsharp observables}, which is essentially new, the
object observable is taken to be a positive operator v alued measure. Both
theorems show that the measurement problem is not the consequence of neglecting
the ever-present imperfections of actual measurements.
| [
{
"version": "v1",
"created": "Mon, 15 Apr 1996 10:51:19 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Busch",
"P.",
"",
"U. Hull"
],
[
"Shimony",
"A.",
"",
"Boston University"
]
] |
quant-ph/9604014 | P. Busch | P. Busch (Applied Maths., University of Hull) | Is the quantum state (an) observable? | plain TeX, 12 pages | In: "Potentiality, Entanglement and Passion-at-a-Distance: Quantum
Mechanical Studies for Abner Shimony." Eds. R.S. Cohen, M.A. Horne, J.
Stachel, Kluwer, Dordrecht, 1997, pp. 61-70. | null | null | quant-ph | null | We explore the sense in which the state of a physical system may or may not
be regarded (an) observable in quantum mechanics. Simple and general arguments
from various lines of approach are reviewed which demonstrate the following
no-go claims: (1) the structure of quantum mechanics precludes the
determination of the state of a single system by means of measurements
performed on that system only; (2) there is no way of using entangled
two-particle states to transmit superluminal signals. Employing the
representation of observables as general positive operator valued measures, our
analysis allows one to indicate whether optimal separation of different states
is achieved by means of sharp or unsharp observables.
| [
{
"version": "v1",
"created": "Tue, 16 Apr 1996 16:38:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Busch",
"P.",
"",
"Applied Maths., University of Hull"
]
] |
quant-ph/9604015 | Seth Lloyd | Seth Lloyd (MIT Mechanical Engineering) | The capacity of the noisy quantum channel | 19 pages, Submitted to Science. Replaced give correct references to
work of Schumacher, to add a figure and an appendix, and to correct minor
mistakes | null | 10.1103/PhysRevA.55.1613 | null | quant-ph | null | An upper limit is given to the amount of quantum information that can be
transmitted reliably down a noisy, decoherent quantum channel. A class of
quantum error-correcting codes is presented that allow the information
transmitted to attain this limit. The result is the quantum analog of Shannon's
bound and code for the noisy classical channel.
| [
{
"version": "v1",
"created": "Fri, 19 Apr 1996 22:28:31 GMT"
},
{
"version": "v2",
"created": "Wed, 1 May 1996 02:52:57 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Lloyd",
"Seth",
"",
"MIT Mechanical Engineering"
]
] |
quant-ph/9604016 | Brif Constantin | C. Brif and Y. Ben-Aryeh (Technion) | Improvement of measurement accuracy in SU(1,1) interferometers | LaTeX, 5 pages, 1 figure (compressed PostScript, available at
http://www.technion.ac.il/~brif/graphics/interfer_graph/qopt.ps.gz ). More
information on http://www.technion.ac.il/~brif/science.html | Quantum Semiclass. Opt. 8 (1996) 1-5 | 10.1088/1355-5111/8/1/001 | null | quant-ph | null | We consider an SU(1,1) interferometer employing four-wave mixers that is fed
with two-mode states which are both coherent and intelligent states of the
SU(1,1) Lie group. It is shown that the phase sensitivity of the interferometer
can be essentially improved by using input states with a large photon-number
difference between the modes.
| [
{
"version": "v1",
"created": "Sat, 20 Apr 1996 09:51:09 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Brif",
"C.",
"",
"Technion"
],
[
"Ben-Aryeh",
"Y.",
"",
"Technion"
]
] |
quant-ph/9604017 | Brif Constantin | C. Brif (1), A. Mann (1) and A. Vourdas (2) ((1) Technion, (2)
University of Liverpool) | Parity-dependent squeezing of light | accepted for publication in J. Phys. A, LaTeX, 11 pages, 12 figures
(compressed PostScript, available at
http://www.technion.ac.il/~brif/graphics/pdss_graph ). More information on
http://www.technion.ac.il/~brif/science.html | J.Phys.A29:2053-2068,1996 | 10.1088/0305-4470/29/9/018 | null | quant-ph | null | A parity-dependent squeezing operator is introduced which imposes different
SU(1,1) rotations on the even and odd subspaces of the harmonic oscillator
Hilbert space. This operator is used to define parity-dependent squeezed states
which exhibit highly nonclassical properties such as strong antibunching,
quadrature squeezing, strong oscillations in the photon-number distribution,
etc. In contrast to the usual squeezed states whose $Q$ and Wigner functions
are simply Gaussians, the parity-dependent squeezed states have much more
complicated $Q$ and Wigner functions that exhibit an interesting interference
in phase space. The generation of these states by parity-dependent quadratic
Hamiltonians is also discussed.
| [
{
"version": "v1",
"created": "Sat, 20 Apr 1996 10:05:18 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Brif",
"C.",
""
],
[
"Mann",
"A.",
""
],
[
"Vourdas",
"A.",
""
]
] |
quant-ph/9604018 | null | Olga Man'ko | Symplectic Tomography of Nonclassical States of Trapped Ion | 11 pages,LATEX,contribution to conference Interferometry 2, to appear
in Russian Laser Research,1996 | null | 10.1016/S0375-9601(97)00091-1 | null | quant-ph | null | The marginal distribution of squeezed and rotated quadrature for two types of
nonclassical states of trapped ion -- for squeezed and correlated states and
for squeezed even and odd coherent states (squeezed Schr\"odinger cat states)
is studied. The obtained marginal distribution for the two types of states is
shown to satisfy classical dynamical equation equivalent to standard quantum
evolution equation for density matrix (wave function) derived in symplectic
tomography scheme.
| [
{
"version": "v1",
"created": "Sun, 21 Apr 1996 12:33:21 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Man'ko",
"Olga",
""
]
] |
quant-ph/9604019 | Mike Ashworth | M. C. Ashworth (UC, Davis) | Constrainted Coherent States | 18 pages. Further explaintion added and some errors corrected | null | null | null | quant-ph gr-qc | null | Coherent states possess a regularized path integral and gives a natural
relation between classical variables and quantum operators. Recent work by
Klauder and Whiting has included extended variables, that can be thought of as
gauge fields, into this formalism. In this paper, I consider the next step, and
look at the roll of first class constraints.
| [
{
"version": "v1",
"created": "Sun, 21 Apr 1996 20:52:12 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Jun 1996 19:35:39 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Ashworth",
"M. C.",
"",
"UC, Davis"
]
] |
quant-ph/9604020 | T. Opatrny | T. Opatrny, D.-G. Welsch, W. Vogel | Multi-mode density matrices of light via amplitude and phase control | 6 pages, latex | null | 10.1016/S0030-4018(96)00548-2 | null | quant-ph | null | A new method is described for determining the quantum state of correlated
multimode radiation by interfering the modes and measuring the statistics of
the superimposed fields in four-port balanced homodyne detection. The full
information on the $N$-mode quantum state is obtained by controlling both the
relative amplitudes and the phases of the modes, which simplifies the
reconstruction of density matrices to only $N+1$ Fourier transforms. In
particular, this method yields time-correlated multimode density matrices of
optical pulses by superimposing the signal by a sequence of short
local-oscillator pulses.
| [
{
"version": "v1",
"created": "Mon, 22 Apr 1996 10:31:01 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Opatrny",
"T.",
""
],
[
"Welsch",
"D. -G.",
""
],
[
"Vogel",
"W.",
""
]
] |
quant-ph/9604021 | Tal Mor | E. Biham, B Huttner, and T Mor | Quantum Cryptographic Network based on Quantum Memories | 16 pages, RevTeX. Submitted to PRA. Figure available upon request
([email protected]) | null | 10.1103/PhysRevA.54.2651 | null | quant-ph | null | Quantum correlations between two particles show non-classical properties
which can be used for providing secure transmission of information. We present
a quantum cryptographic system, in which users store particles in quantum
memories kept in a transmission center. Correlations between the particles
stored by two users are created upon request by projecting their product state
onto a fully entangled state. Our system allows for secure communication
between any pair of users who have particles in the same center. Unlike other
quantum cryptographic systems, it can work without quantum channels and is
suitable for building a quantum cryptographic network. We also present a
modified system with many centers.
| [
{
"version": "v1",
"created": "Mon, 22 Apr 1996 10:52:14 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Biham",
"E.",
""
],
[
"Huttner",
"B",
""
],
[
"Mor",
"T",
""
]
] |
quant-ph/9604022 | Michael Nielsen | Benjamin Schumacher and M. A. Nielsen | Quantum data processing and error correction | LaTeX, 20 pages | null | 10.1103/PhysRevA.54.2629 | null | quant-ph | null | This paper investigates properties of noisy quantum information channels. We
define a new quantity called {\em coherent information} which measures the
amount of quantum information conveyed in the noisy channel. This quantity can
never be increased by quantum information processing, and it yields a simple
necessary and sufficient condition for the existence of perfect quantum error
correction.
| [
{
"version": "v1",
"created": "Mon, 22 Apr 1996 21:34:35 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Schumacher",
"Benjamin",
""
],
[
"Nielsen",
"M. A.",
""
]
] |
quant-ph/9604023 | Benjamin Schumacher | Benjamin Schumacher | Sending quantum entanglement through noisy channels | LaTeX, 39 pages | null | null | null | quant-ph | null | This paper addresses some general questions of quantum information theory
arising from the transmission of quantum entanglement through (possibly noisy)
quantum channels. A pure entangled state is prepared of a pair of systems $R$
and $Q$, after which $Q$ is subjected to a dynamical evolution given by the
superoperator $\superop^{Q}$. Two interesting quantities can be defined for
this process: the entanglement fidelity $F_{e}$ and the entropy production
$S_{e}$. It turns out that neither of these quantities depends in any way on
the system $R$, but only on the initial state and dynamical evolution of $Q$.
$F_{e}$ and $S_{e}$ are related to various other fidelities and entropies, and
are connected by an inequality reminiscent of the Fano inequality of classical
information theory. Some insight can be gained from these techniques into the
security of quantum cryptographic protocols and the nature of quantum
error-correcting codes.
| [
{
"version": "v1",
"created": "Mon, 22 Apr 1996 22:07:40 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Schumacher",
"Benjamin",
""
]
] |
quant-ph/9604024 | John Smolin | Charles H. Bennett, David P. DiVincenzo, John A. Smolin, William K.
Wootters | Mixed State Entanglement and Quantum Error Correction | Resubmission with various corrections and expansions. See also
http://vesta.physics.ucla.edu/~smolin/ for related papers and information. 82
pages latex including 19 postscript figures included using psfig macros | Phys.Rev.A54:3824-3851,1996 | 10.1103/PhysRevA.54.3824 | null | quant-ph | null | Entanglement purification protocols (EPP) and quantum error-correcting codes
(QECC) provide two ways of protecting quantum states from interaction with the
environment. In an EPP, perfectly entangled pure states are extracted, with
some yield D, from a mixed state M shared by two parties; with a QECC, an arbi-
trary quantum state $|\xi\rangle$ can be transmitted at some rate Q through a
noisy channel $\chi$ without degradation. We prove that an EPP involving one-
way classical communication and acting on mixed state $\hat{M}(\chi)$ (obtained
by sharing halves of EPR pairs through a channel $\chi$) yields a QECC on
$\chi$ with rate $Q=D$, and vice versa. We compare the amount of entanglement
E(M) required to prepare a mixed state M by local actions with the amounts
$D_1(M)$ and $D_2(M)$ that can be locally distilled from it by EPPs using one-
and two-way classical communication respectively, and give an exact expression
for $E(M)$ when $M$ is Bell-diagonal. While EPPs require classical communica-
tion, QECCs do not, and we prove Q is not increased by adding one-way classical
communication. However, both D and Q can be increased by adding two-way com-
munication. We show that certain noisy quantum channels, for example a 50%
depolarizing channel, can be used for reliable transmission of quantum states
if two-way communication is available, but cannot be used if only one-way com-
munication is available. We exhibit a family of codes based on universal hash-
ing able toachieve an asymptotic $Q$ (or $D$) of 1-S for simple noise models,
where S is the error entropy. We also obtain a specific, simple 5-bit single-
error-correcting quantum block code. We prove that {\em iff} a QECC results in
high fidelity for the case of no error the QECC can be recast into a form where
the encoder is the matrix inverse of the decoder.
| [
{
"version": "v1",
"created": "Tue, 23 Apr 1996 06:32:41 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Aug 1996 18:10:03 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Bennett",
"Charles H.",
""
],
[
"DiVincenzo",
"David P.",
""
],
[
"Smolin",
"John A.",
""
],
[
"Wootters",
"William K.",
""
]
] |
quant-ph/9604025 | Dr Bindu A. bhamba | Bindu A. Bambah (University of Hyderabad, India), G.S. Agarwal
(Physical Research Lab., Ahmedabad.) | Coherent States for Kronecker Products of Non-Compact Groups:
Formulation and Applications | 7 pages, 2 figures (can be obtained from author by snail mail) | Invited talk published in "Proc. of the fourth int. conf. on
Squeezed States and Uncertainty Relations", NASA Conf. Pub.3322.(1995) | null | null | quant-ph | null | We introduce and study the properties of a class of coherent states for the
group SU(1,1) X SU(1,1) and derive explicit expressions for these using the
Clebsch-Gordan algebra for the SU(1,1) group. We restrict ourselves to the
discrete series representations of SU(1,1). These are the generalization of the
`Barut Girardello' coherent states to the Kronecker Product of two non-compact
groups.The resolution of the identity and the analytic phase space
representation of these states is presented. This phase space representation is
based on the basis of products of `pair coherent states' rather than the
standard number state canonical basis. We discuss the utility of the resulting
`bi-pair coherent states' in the context of four-mode interactions in quantum
optics.
| [
{
"version": "v1",
"created": "Tue, 23 Apr 1996 18:51:29 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Bambah",
"Bindu A.",
"",
"University of Hyderabad, India"
],
[
"Agarwal",
"G. S.",
"",
"Physical Research Lab., Ahmedabad."
]
] |
quant-ph/9604026 | Raymond LaFlamme | Richard J. Hughes, Daniel F. V. James, Emanuel H. Knill, Raymond
Laflamme and Albert G. Petschek | Decoherence Bounds on Quantum Computation with Trapped Ions | 5 pages in RevTex, 2 figures, the paper is also avalaible at
http://qso.lanl.gov/qc/ | null | 10.1103/PhysRevLett.77.3240 | LA-UR 96-1266 | quant-ph | null | Using simple physical arguments we investigate the capabilities of a quantum
computer based on cold trapped ions. From the limitations imposed on such a
device by spontaneous decay, laser phase coherence, ion heating and other
sources of error, we derive a bound between the number of laser interactions
and the number of ions that may be used. The largest number which may be
factored using a variety of species of ion is determined.
| [
{
"version": "v1",
"created": "Tue, 23 Apr 1996 23:16:37 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Hughes",
"Richard J.",
""
],
[
"James",
"Daniel F. V.",
""
],
[
"Knill",
"Emanuel H.",
""
],
[
"Laflamme",
"Raymond",
""
],
[
"Petschek",
"Albert G.",
""
]
] |
quant-ph/9604027 | A. Jabs [Prof. DF | Arthur Jabs (UFPB Jo\~ao Pessoa Brasil, LMU M\"unchen Germany) | Einstein-Podolsky-Rosen Correlations in Deuteron Photodisintegration | 8 pages, 1 Figure (missing, may be obtained via air mail) | null | null | null | quant-ph nucl-ex nucl-th | null | Einstein-Podolsky-Rosen correlations have so far been measured only between
pairs of photons and between pairs of protons. It is proposed to measure these
correlations between the proton and the neutron emerging from breakup of the
deuteron induced by gamma rays near threshold. The feasibility of the
experiment is discussed. Polarimeters with substantially higher overall
efficiency than the presently reported value of $10^{-4}$ are needed in order
to get enough events.
| [
{
"version": "v1",
"created": "Wed, 24 Apr 1996 15:30:39 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Jabs",
"Arthur",
"",
"UFPB João Pessoa Brasil, LMU München Germany"
]
] |
quant-ph/9604028 | Chiara Macchiavello | Adriano Barenco, Andre` Berthiaume, David Deutsch, Artur Ekert,
Richard Jozsa and Chiara Macchiavello | Stabilisation of Quantum Computations by Symmetrisation | 20 pages LaTeX, 2 postscript figures | null | null | null | quant-ph | null | We propose a method for the stabilisation of quantum computations (including
quantum state storage). The method is based on the operation of projection into
$\cal SYM$, the symmetric subspace of the full state space of $R$ redundant
copies of the computer. We describe an efficient algorithm and quantum network
effecting $\cal SYM$--projection and discuss the stabilising effect of the
proposed method in the context of unitary errors generated by hardware
imprecision, and nonunitary errors arising from external environmental
interaction. Finally, limitations of the method are discussed.
| [
{
"version": "v1",
"created": "Thu, 25 Apr 1996 10:58:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Barenco",
"Adriano",
""
],
[
"Berthiaume",
"Andre`",
""
],
[
"Deutsch",
"David",
""
],
[
"Ekert",
"Artur",
""
],
[
"Jozsa",
"Richard",
""
],
[
"Macchiavello",
"Chiara",
""
]
] |
quant-ph/9604029 | Lior Goldenberg | Lior Goldenberg and Lev Vaidman | Reply to Comment: Quantum Cryptography Based on Orthogonal States? | 3 pages, LaTex, no figures | null | null | null | quant-ph | null | This is our Reply to Peres' Comment [quant-ph/9509003] to "Quantum
Cryptography Based on Orthogonal States" [Phys. Rev. Lett. 75, 1239 (1995)].
| [
{
"version": "v1",
"created": "Thu, 25 Apr 1996 11:42:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Goldenberg",
"Lior",
""
],
[
"Vaidman",
"Lev",
""
]
] |
quant-ph/9604030 | Isaac Chuang | Isaac L. Chuang and Yoshihisa Yamamoto (ERATO Quantum Fluctuation
Project, Ginzton Laboratory, Stanford University) | The Persistent Quantum Bit | 15 pages, postscript only, figures also available at
http://feynman.stanford.edu/qcomp/ | null | null | null | quant-ph | null | The construction of large, coherent quantum systems necessary for quantum
computation remains an entreating but elusive goal, due to the ubiquitous
nature of decoherence. Recent progress in quantum error correction schemes have
given new hope to this field, but thus far, the codes presented in the
literature assume a restricted number of errors and error free encoding,
decoding, and measurement. We investigate a specific scenario without these
assumptions; in particular, we evaluate a scheme to preserve a single quantum
bit against phase damping using a three-qubit encoding based on Shor. By
applying a new formalism which gives simple operators for decoherence and noisy
logic gates, we find the fidelity of the stored qubit as a function of time,
including decoherence which occurs not only during storage but also during
processing. We generalize our results to include any source of error, and
derive an upper limit on the allowable decoherence per timestep. Physically,
our results suggest the feasibility of engineering artificial metastable states
through repeated error correction.
| [
{
"version": "v1",
"created": "Thu, 25 Apr 1996 22:18:55 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Apr 1996 06:36:43 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Chuang",
"Isaac L.",
"",
"ERATO Quantum Fluctuation\n Project, Ginzton Laboratory, Stanford University"
],
[
"Yamamoto",
"Yoshihisa",
"",
"ERATO Quantum Fluctuation\n Project, Ginzton Laboratory, Stanford University"
]
] |
quant-ph/9604031 | Isaac Chuang | Isaac L. Chuang and Yoshihisa Yamamoto (ERATO Quantum Fluctuation
Project, Ginzton Laboratory, Stanford University) | Quantum Bit Regeneration | 4 pages, postscript only, figures available at
http://feynman.stanford.edu/qcomp | Phys. Rev. Lett. May 13, 1996 | 10.1103/PhysRevLett.76.4281 | null | quant-ph | null | Decoherence and loss will limit the practicality of quantum cryptography and
computing unless successful error correction techniques are developed. To this
end, we have discovered a new scheme for perfectly detecting and rejecting the
error caused by loss (amplitude damping to a reservoir at T=0), based on using
a dual-rail representation of a quantum bit. This is possible because (1)
balanced loss does not perform a ``which-path'' measurement in an
interferometer, and (2) balanced quantum nondemolition measurement of the
``total'' photon number can be used to detect loss-induced quantum jumps
without disturbing the quantum coherence essential to the quantum bit. Our
results are immediately applicable to optical quantum computers using single
photonics devices.
| [
{
"version": "v1",
"created": "Thu, 25 Apr 1996 22:26:08 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Chuang",
"Isaac L.",
"",
"ERATO Quantum Fluctuation\n Project, Ginzton Laboratory, Stanford University"
],
[
"Yamamoto",
"Yoshihisa",
"",
"ERATO Quantum Fluctuation\n Project, Ginzton Laboratory, Stanford University"
]
] |
quant-ph/9604032 | John Klauder | John R. Klauder (University of Florida) | Is Quantization Geometry? | Latex, 18 pages, no figures | null | null | null | quant-ph | null | The metric known to be relevant for standard quantization procedures receives
a natural interpretation and its explicit use simultaneously gives both
physical and mathematical meaning to a (coherent-state) phase-space path
integral, and at the same time establishes a fully satisfactory, geometric
procedure of quantization.
| [
{
"version": "v1",
"created": "Fri, 26 Apr 1996 09:21:28 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Klauder",
"John R.",
"",
"University of Florida"
]
] |
quant-ph/9604033 | John Klauder | John R. Klauder (University of Florida) | Coherent State Quantization of Constraint Systems | Latex, 38 pages, no figures | Annals Phys. 254 (1997) 419-453 | 10.1006/aphy.1996.5647 | null | quant-ph | null | A careful reexamination of the quantization of systems with first- and
second-class constraints from the point of view of coherent-state phase-space
path integration reveals several significant distinctions from more
conventional treatments. Most significantly, we emphasize the importance of
using path-integral measures for Lagrange multipliers which ensure that the
quantum system satisfies the quantum constraint conditions. Our procedures
involve no delta-functionals of the classical constraints, no need for gauge
fixing of first-class constraints, no need to eliminate second-class
constraints, no potentially ambiguous determinants, and have the virtue of
resolving differences between canonical and path-integral approaches. Several
examples are considered in detail.
| [
{
"version": "v1",
"created": "Fri, 26 Apr 1996 14:16:10 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Klauder",
"John R.",
"",
"University of Florida"
]
] |
quant-ph/9604034 | Raymond LaFlamme | Emanuel Knill and Raymond Laflamme | A Theory of Quantum Error-Correcting Codes | 34 pages in LaTex, 1 figures, the paper is also available at
http://qso.lanl.gov/qc/ | Phys.Rev.Lett.84:2525-2528,2000 | 10.1103/PhysRevLett.84.2525 | LA-UR 96-1300 | quant-ph | null | Quantum Error Correction will be necessary for preserving coherent states
against noise and other unwanted interactions in quantum computation and
communication. We develop a general theory of quantum error correction based on
encoding states into larger Hilbert spaces subject to known interactions. We
obtain necessary and sufficient conditions for the perfect recovery of an
encoded state after its degradation by an interaction. The conditions depend
only on the behavior of the logical states. We use them to give a recovery
operator independent definition of error-correcting codes. We relate this
definition to four others: The existence of a left inverse of the interaction,
an explicit representation of the error syndrome using tensor products, perfect
recovery of the completely entangled state, and an information theoretic
identity. Two notions of fidelity and error for imperfect recovery are
introduced, one for pure and the other for entangled states. The latter is more
appropriate when using codes in a quantum memory or in applications of quantum
teleportation to communication. We show that the error for entangled states is
bounded linearly by the error for pure states. A formal definition of
independent interactions for qubits is given. This leads to lower bounds on the
number of qubits required to correct $e$ errors and a formal proof that the
classical bounds on the probability of error of $e$-error-correcting codes
applies to $e$-error-correcting quantum codes, provided that the interaction is
dominated by an identity component.
| [
{
"version": "v1",
"created": "Fri, 26 Apr 1996 21:39:52 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Knill",
"Emanuel",
""
],
[
"Laflamme",
"Raymond",
""
]
] |
quant-ph/9604035 | Bruce Boghosian | Bruce M. Boghosian (BU) and Washington Taylor (Princeton U.) | A Quantum Lattice-Gas Model for the Many-Particle Schroedinger Equation | 19 pages LaTeX, one illustration | null | null | BU-CCS-960401, PUPT-1615 (Revision 1) | quant-ph comp-gas hep-lat nlin.CG | null | We consider a general class of discrete unitary dynamical models on the
lattice. We show that generically such models give rise to a wavefunction
satisfying a Schroedinger equation in the continuum limit, in any number of
dimensions. There is a simple mathematical relationship between the mass of the
Schroedinger particle and the eigenvalues of a unitary matrix describing the
local evolution of the model. Second quantized versions of these unitary models
can be defined, describing in the continuum limit the evolution of a
nonrelativistic quantum many-body theory. An arbitrary potential is easily
incorporated into these systems. The models we describe fall in the class of
quantum lattice gas automata, and can be implemented on a quantum computer with
a speedup exponential in the number of particles in the system. This gives an
efficient algorithm for simulating general nonrelativistic interacting quantum
many-body systems on a quantum computer.
| [
{
"version": "v1",
"created": "Mon, 29 Apr 1996 00:03:29 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Jan 1997 02:17:31 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Boghosian",
"Bruce M.",
"",
"BU"
],
[
"Taylor",
"Washington",
"",
"Princeton U."
]
] |
quant-ph/9604036 | S. Braunstein | Samuel L. Braunstein, John A. Smolin | Perfect quantum error correction coding in 24 laser pulses | Replacement paper: Lost two laser pulses gained one author; added
appendix with circuits easily implementable on an ion-trap computer | null | 10.1103/PhysRevA.55.945 | null | quant-ph | null | An efficient coding circuit is given for the perfect quantum error correction
of a single qubit against arbitrary 1-qubit errors within a 5 qubit code. The
circuit presented employs a double `classical' code, i.e., one for bit flips
and one for phase shifts. An implementation of this coding circuit on an
ion-trap quantum computer is described that requires 26 laser pulses. A further
circuit is presented requiring only 24 laser pulses, making it an efficient
protection scheme against arbitrary 1-qubit errors. In addition, the
performance of two error correction schemes, one based on the quantum Zeno
effect and the other using standard methods, is compared. The quantum Zeno
error correction scheme is found to fail completely for a model of noise based
on phase-diffusion.
| [
{
"version": "v1",
"created": "Mon, 29 Apr 1996 09:50:09 GMT"
},
{
"version": "v2",
"created": "Tue, 22 Oct 1996 09:10:54 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Braunstein",
"Samuel L.",
""
],
[
"Smolin",
"John A.",
""
]
] |
quant-ph/9604037 | Mayburov S. N. | S.N.Mayburov (Lebedev Inst. of Physics, Moscow, Russia) | Radiation Decohernce, State Vector Collapse and QED Nonequivalent
Representations | 6 pages , Submitted to Appl. Phys B , Special issue on QND
measurements | null | null | null | quant-ph | null | The state vector evolution in the interaction of initial measured pure state
with collective quantum system or the field with a very large number of degrees
of freedom N is analysed in a nonperturbative QED formalism. As the example the
measurement of the electron final state scattered on nucleus or neutrino is
considered.In the nonperturbative field theory the complete manifold of the
system states is nonseparable i.e. is described by tensor product of infinitely
many independent Hilbert spaces. The interaction of this system with the
measured state can result in the final states which belong to different Hilbert
spaces which corresponds to different values of some classical observables,i.e.
spontaneous symmetry breaking occurs. Interference terms (IT) between such
states in the measurement of any Hermitian observable are infinitely small and
due to it the final pure states can't be distinguished from the mixed ones,
characteristic for the state collapse. The evolution from initial to final
system state is nonunitary and become formally irreversible in the limit of
infinite time. The electromagnetic (e-m) bremmstrahlung produced in the
electron scattering process contain the unrestricted number of soft photons
which radiation flux become classic observable. Analoguous processes which
occurs in the second kind phase transitions in ferromagnetic and phonon
excitations in cristall lattice are considered briefly.
| [
{
"version": "v1",
"created": "Mon, 29 Apr 1996 11:13:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mayburov",
"S. N.",
"",
"Lebedev Inst. of Physics, Moscow, Russia"
]
] |
quant-ph/9604038 | Daniel Gottesman | Daniel Gottesman | A Class of Quantum Error-Correcting Codes Saturating the Quantum Hamming
Bound | REVTeX, 22 pages; introduction clarified and corrected to explicitly
include non-orthogonal codes, claim of appendix A restricted to possibly
allow some 1-error degenerate codes, references added; to appear in Phys.
Rev. A | Phys.Rev. A54 (1996) 1862 | 10.1103/PhysRevA.54.1862 | CALT-68-2055 | quant-ph | null | I develop methods for analyzing quantum error-correcting codes, and use these
methods to construct an infinite class of codes saturating the quantum Hamming
bound. These codes encode $k=n-j-2$ qubits in $n=2^j$ qubits and correct $t=1$
error.
| [
{
"version": "v1",
"created": "Mon, 29 Apr 1996 18:08:41 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Jul 1996 19:00:09 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Gottesman",
"Daniel",
""
]
] |
quant-ph/9604039 | Anna Sanpera | D. Deutsch, A. Ekert, R. Jozsa, C. Macchiavello, S. Popescu, and A.
Sanpera (Clarendon Lab. University of Oxford, UK) | Quantum privacy amplification and the security of quantum cryptography
over noisy channels | 13 pages, Latex including 2 postcript files included using psfig
macros | Phys.Rev.Lett.77:2818-2821,1996; Erratum-ibid.80:2022-2022,1998 | 10.1103/PhysRevLett.77.2818 | null | quant-ph | null | Existing quantum cryptographic schemes are not, as they stand, operable in
the presence of noise on the quantum communication channel. Although they
become operable if they are supplemented by classical privacy-amplification
techniques, the resulting schemes are difficult to analyse and have not been
proved secure. We introduce the concept of quantum privacy amplification and a
cryptographic scheme incorporating it which is provably secure over a noisy
channel. The scheme uses an `entanglement purification' procedure which,
because it requires only a few quantum Controlled-Not and single-qubit
operations, could be implemented using technology that is currently being
developed. The scheme allows an arbitrarily small bound to be placed on the
information that any eavesdropper may extract from the encrypted message.
| [
{
"version": "v1",
"created": "Tue, 30 Apr 1996 09:03:34 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Deutsch",
"D.",
"",
"Clarendon Lab. University of Oxford, UK"
],
[
"Ekert",
"A.",
"",
"Clarendon Lab. University of Oxford, UK"
],
[
"Jozsa",
"R.",
"",
"Clarendon Lab. University of Oxford, UK"
],
[
"Macchiavello",
"C.",
"",
"Clarendon Lab. University of Oxford, UK"
],
[
"Popescu",
"S.",
"",
"Clarendon Lab. University of Oxford, UK"
],
[
"Sanpera",
"A.",
"",
"Clarendon Lab. University of Oxford, UK"
]
] |
quant-ph/9604040 | Tal Mor | C. H. Bennett, T. Mor, and J. A. Smolin | The Parity Bit in Quantum Cryptography | 19 pages, RevTeX | null | 10.1103/PhysRevA.54.2675 | null | quant-ph | null | An $n$-bit string is encoded as a sequence of non-orthogonal quantum states.
The parity bit of that $n$-bit string is described by one of two density
matrices, $\rho_0^{(n)}$ and $\rho_1^{(n)}$, both in a Hilbert space of
dimension $2^n$. In order to derive the parity bit the receiver must
distinguish between the two density matrices, e.g., in terms of optimal mutual
information. In this paper we find the measurement which provides the optimal
mutual information about the parity bit and calculate that information. We
prove that this information decreases exponentially with the length of the
string in the case where the single bit states are almost fully overlapping. We
believe this result will be useful in proving the ultimate security of quantum
crytography in the presence of noise.
| [
{
"version": "v1",
"created": "Tue, 30 Apr 1996 14:44:04 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Bennett",
"C. H.",
""
],
[
"Mor",
"T.",
""
],
[
"Smolin",
"J. A.",
""
]
] |
quant-ph/9605001 | Cristian Calude | I. Antoniou, B. Pavlov, A. Yafyasov | Quantum Electronic Devices Based on Metal-Dielectric Transition in
Low-Dimensional Quantum Structures | null | null | null | null | quant-ph | null | Two types of optically manipulated quantum electronic devices are considered:
a quantum dot and a finite periodic molecular chain, with the period doubled
under resonance optical excitation. The stability of the working regimes of the
devices in large scale of temperatures is discussed. Some motivation in favor
of the molecular chain is suggested. A class of materials, which can be used
for producing this device is discussed.
| [
{
"version": "v1",
"created": "Thu, 2 May 1996 20:41:21 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Antoniou",
"I.",
""
],
[
"Pavlov",
"B.",
""
],
[
"Yafyasov",
"A.",
""
]
] |
quant-ph/9605002 | Nicolas Cerf | N. J. Cerf, C. Adami (California Institute of Technology) | Quantum Mechanics of Measurement | 18 pages RevTex incl. 8 figures, submitted to Phys. Rev. A. Revised
abstract and introduction. Added discussion on separability and entropic
uncertainty relations | null | null | KRL-MAP-198 | quant-ph | null | An analysis of quantum measurement is presented that relies on an
information-theoretic description of quantum entanglement. In a consistent
quantum information theory of entanglement, entropies (uncertainties)
conditional on measurement outcomes can be negative, implying that measurement
can be described via unitary, entropy-conserving, interactions, while still
producing randomness in a measurement device. In such a framework, quantum
measurement is not accompanied by a wave-function collapse, or a quantum jump.
The theory is applied to the measurement of incompatible variables, giving rise
to a stronger entropic uncertainty relation than heretofore known. It is also
applied to standard quantum measurement situations such as the Stern-Gerlach
and double-slit experiments to illustrate how randomness, inherent in the
conventional quantum probabilities, arises in a unitary framework. Finally, the
present view clarifies the relationship between classical and quantum concepts.
| [
{
"version": "v1",
"created": "Fri, 3 May 1996 00:12:39 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Feb 1997 19:19:20 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Cerf",
"N. J.",
"",
"California Institute of Technology"
],
[
"Adami",
"C.",
"",
"California Institute of Technology"
]
] |
quant-ph/9605003 | null | Won Young Hwang and In Gyu Koh (KAIST, Korea) and Yeong Deok Han
(Woosuk University, Korea) | A note on the supplementary variables in spin-measuring equipments in
the EPR-Bell experiment | 5 pages | null | null | null | quant-ph | null | We discuss supplementary (or hidden) variables in spin-measuring equipments
in EPR-Bell experiment. This theme was considered in a Bell's later work. We
generalize it. First, we show why the original supplementary variable $\lambda$
is not to be regarded to include supplementary variables in spin-measuring
equipments (why supplementary variables should be introduced additionally in
spin-measuring equipments) Next, we show the followings. When the supplementary
variables introduced in spin-measuring equipments have local correlations, the
Bell inequality is recovered. On the other hand, when they have nonlocal
correlations, the Bell inequality is not recovered. This fact is in accord with
the fact that the Bell inequality is derived for local realistic models.
| [
{
"version": "v1",
"created": "Fri, 3 May 1996 00:18:17 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Feb 1997 14:56:45 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Hwang",
"Won Young",
"",
"KAIST, Korea"
],
[
"Koh",
"In Gyu",
"",
"KAIST, Korea"
],
[
"Han",
"Yeong Deok",
"",
"Woosuk University, Korea"
]
] |
quant-ph/9605004 | Daniel Rohrlich | Sandu Popescu and Daniel Rohrlich | Action and Passion at a Distance: An Essay in Honor of Professor Abner
Shimony | 16 pages, RevTeX, no figures | null | null | TAUP 2334-96 | quant-ph | null | Quantum mechanics permits nonlocality---both nonlocal correlations and
nonlocal equations of motion---while respecting relativistic causality. Is
quantum mechanics the unique theory that reconciles nonlocality and causality?
We consider two models, going beyond quantum mechanics, of
nonlocality---``superquantum" correlations, and nonlocal ``jamming" of
correlations---and derive new results for the jamming model. In one space
dimension, jamming allows reversal of the sequence of cause and effect; in
higher dimensions, however, effect never precedes cause.
| [
{
"version": "v1",
"created": "Fri, 3 May 1996 09:53:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Popescu",
"Sandu",
""
],
[
"Rohrlich",
"Daniel",
""
]
] |
quant-ph/9605005 | Peter W. Shor | A. R. Calderbank (1), E. M Rains (2), P. W. Shor (1), and N. J. A.
Sloane (1) ((1) AT&T Research, (2) Institute for Defense Analysis) | Quantum Error Correction and Orthogonal Geometry | RevTex, 4 pages, no figures, submitted to Phys. Rev. Letters. We have
changed the statement of Theorem 2 to correct it -- we now get worse rates
than we previously claimed for our quantum codes. Minor changes have been
made to the rest of the paper | Phys.Rev.Lett.78:405-408,1997 | 10.1103/PhysRevLett.78.405 | null | quant-ph | null | A group theoretic framework is introduced that simplifies the description of
known quantum error-correcting codes and greatly facilitates the construction
of new examples. Codes are given which map 3 qubits to 8 qubits correcting 1
error, 4 to 10 qubits correcting 1 error, 1 to 13 qubits correcting 2 errors,
and 1 to 29 qubits correcting 5 errors.
| [
{
"version": "v1",
"created": "Thu, 9 May 1996 03:59:00 GMT"
},
{
"version": "v2",
"created": "Thu, 9 May 1996 17:03:00 GMT"
},
{
"version": "v3",
"created": "Tue, 2 Jul 1996 18:12:00 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Calderbank",
"A. R.",
"",
"AT&T Research"
],
[
"Rains",
"E. M",
"",
"Institute for Defense Analysis"
],
[
"Shor",
"P. W.",
"",
"AT&T Research"
],
[
"Sloane",
"N. J. A.",
"",
"AT&T Research"
]
] |
quant-ph/9605006 | Brif Constantin | C. Brif (Technion, Haifa) | Two-Photon Algebra Eigenstates: A Unified Approach to Squeezing | To appear in Annals of Physics, REVTeX with AMSsymbols, 27 pages, no
figures. More information on http://www.technion.ac.il/~brif/science.html | Annals Phys. 251 (1996) 180 | 10.1006/aphy.1996.0112 | null | quant-ph | null | We use the concept of the algebra eigenstates that provides a unified
description of the generalized coherent states (belonging to different sets)
and of the intelligent states associated with a dynamical symmetry group. The
formalism is applied to the two-photon algebra and the corresponding algebra
eigenstates are studied by using the Fock-Bargmann analytic representation.
This formalism yields a unified analytic approach to various types of
single-mode photon states generated by squeezing and displacing
transformations.
| [
{
"version": "v1",
"created": "Sat, 11 May 1996 08:30:50 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Brif",
"C.",
"",
"Technion, Haifa"
]
] |
quant-ph/9605007 | Tal Mor | E. Biham and T. Mor | On the Security of Quantum Cryptography Against Collective Attacks | 10 pages, RevTeX. New version. To be published in Phys. Rev. Lett | null | 10.1103/PhysRevLett.78.2256 | null | quant-ph | null | We present strong attacks against quantum key distribution schemes which use
quantum memories and quantum gates to attack directly the final key. We analyze
a specific attack of this type, for which we find the density matrices
available to the eavesdropper and the optimal information which can be
extracted from them. We prove security against this attack and discuss security
against any attack allowed by the rules of quantum mechanics.
| [
{
"version": "v1",
"created": "Sat, 11 May 1996 20:28:29 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Jan 1997 15:24:40 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Biham",
"E.",
""
],
[
"Mor",
"T.",
""
]
] |
quant-ph/9605008 | Hiromichi Nakazato | Hiromichi Nakazato, Mikio Namiki (Dept. of Phys, Waseda Univ., Japan),
Saverio Pascazio (Dipt. di Fisica, Univ. di Bari and INFN, Bari, Italy) and
Helmut Rauch (Atominstitut, Wien, Austria) | Understanding the quantum Zeno effect | 9 pages, LaTeX, including 1 epsfigure, tar+gzip+uuencoded to appear
in Phys. Lett. A | null | 10.1016/0375-9601(96)00350-7 | null | quant-ph | null | The quantum Zeno effect consists in the hindrance of the evolution of a
quantum system that is very frequently monitored and found to be in its initial
state at every single measurement. On the basis of the correct formula for the
survival probability, i.e. the probability of finding the system in its initial
state at every single measurement, we critically analyze a recent proposal and
experimental test, that make use of an oscillating system.
| [
{
"version": "v1",
"created": "Mon, 13 May 1996 09:13:10 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Nakazato",
"Hiromichi",
"",
"Dept. of Phys, Waseda Univ., Japan"
],
[
"Namiki",
"Mikio",
"",
"Dept. of Phys, Waseda Univ., Japan"
],
[
"Pascazio",
"Saverio",
"",
"Dipt. di Fisica, Univ. di Bari and INFN, Bari, Italy"
],
[
"Rauch",
"Helmut",
"",
"Atominstitut, Wien, Austria"
]
] |
quant-ph/9605009 | Asher Peres | Asher Peres | Error symmetrization in quantum computers | 3 pages LaTeX, extended abstract for PhysComp96 | Int.J.Theor.Phys. 38 (1999) 799-805 | null | null | quant-ph | null | It is possible to reduce some types of quantum computation errors by
symmetrizing the quantum state of a redundant array. Various models are
discussed.
| [
{
"version": "v1",
"created": "Mon, 13 May 1996 09:32:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Peres",
"Asher",
""
]
] |
quant-ph/9605010 | Tal Mor | E. Biahm and T. Mor | Bounds on Information and the Security of Quantum Cryptography | 11 pages, LaTex, 1 figure. Submitted to Physical Review Letters. This
new version is much different from the previous (conference) version. It
contains explicit calculations of the maximal information obtained by various
eavesdropping attacks on the final key, and suggests that quantum key
distribution is ultimately secure | null | null | null | quant-ph | null | Strong attacks against quantum key distribution use quantum memories and
quantum gates to attack directly the final key. In this paper we extend a novel
security result recently obtained, to demonstrate proofs of security against a
wide class of such attacks. To reach this goal we calculate
information-dependent reduced density matrices, we study the geometry of
quantum mixed states, and we find bounds on the information leaked to an
eavesdropper. Our result suggests that quantum cryptography is ultimately
secure.
| [
{
"version": "v1",
"created": "Mon, 13 May 1996 14:10:34 GMT"
},
{
"version": "v2",
"created": "Wed, 8 Jan 1997 17:14:31 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Biahm",
"E.",
""
],
[
"Mor",
"T.",
""
]
] |
quant-ph/9605011 | Peter W. Shor | Peter W. Shor (AT&T Research) | Fault-tolerant quantum computation | Latex, 11 pages, no figures, in 37th Symposium on Foundations of
Computing, IEEE Computer Society Press, 1996, pp. 56-65 | null | null | null | quant-ph | null | Recently, it was realized that use of the properties of quantum mechanics
might speed up certain computations dramatically. Interest in quantum
computation has since been growing. One of the main difficulties of realizing
quantum computation is that decoherence tends to destroy the information in a
superposition of states in a quantum computer, thus making long computations
impossible. A futher difficulty is that inaccuracies in quantum state
transformations throughout the computation accumulate, rendering the output of
long computations unreliable. It was previously known that a quantum circuit
with t gates could tolerate O(1/t) amounts of inaccuracy and decoherence per
gate. We show, for any quantum computation with t gates, how to build a
polynomial size quantum circuit that can tolerate O(1/(log t)^c) amounts of
inaccuracy and decoherence per gate, for some constant c. We do this by showing
how to compute using quantum error correcting codes. These codes were
previously known to provide resistance to errors while storing and transmitting
quantum data.
| [
{
"version": "v1",
"created": "Mon, 13 May 1996 14:29:00 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Mar 1997 01:42:43 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Shor",
"Peter W.",
"",
"AT&T Research"
]
] |
quant-ph/9605012 | Hiromichi Nakazato | Hiromichi Nakazato, Mikio Namiki (Dept. of Phys, Waseda Univ., Japan),
Saverio Pascazio (Dipt. di Fisica, Univ. di Bari and INFN, Bari, Italy) and
Yoshiya Yamanaka (Dept. of Phys, Waseda Univ., Japan) | Quantum dephasing by chaos | 13 pages, LaTeX, including 1 epsfigure, tar+gzip+uuencoded | null | 10.1016/0375-9601(96)00647-0 | WU-HEP-96-7, BA-TH/96-231 | quant-ph chao-dyn nlin.CD | null | We examine whether the chaotic behavior of classical systems with a limited
number of degrees of freedom can produce quantum dephasing, against the
conventional idea that dephasing takes place only in large systems with a huge
number of constituents and complicated internal interactions. On the basis of
this analysis, we briefly discuss the possibility of defining quantum chaos and
of inventing a ``chaos detector".
| [
{
"version": "v1",
"created": "Tue, 14 May 1996 12:51:36 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Nakazato",
"Hiromichi",
"",
"Dept. of Phys, Waseda Univ., Japan"
],
[
"Namiki",
"Mikio",
"",
"Dept. of Phys, Waseda Univ., Japan"
],
[
"Pascazio",
"Saverio",
"",
"Dipt. di Fisica, Univ. di Bari and INFN, Bari, Italy"
],
[
"Yamanaka",
"Yoshiya",
"",
"Dept. of Phys, Waseda Univ., Japan"
]
] |
quant-ph/9605013 | Raymond LaFlamme | Wojciech Hubert Zurek and Raymond Laflamme | Quantum Logical Operations on Encoded Qubits | 5 pages in LaTex, 6 figures, submitted to Physical Review Letters,
(May 12, 1996), the paper is also avalaible at http://qso.lanl.gov/qc/ | null | 10.1103/PhysRevLett.77.4683 | null | quant-ph | null | We show how to carry out quantum logical operations (controlled-not and
Toffoli gates) on encoded qubits for several encodings which protect against
various 1-bit errors. This improves the reliability of these operations by
allowing one to correct for one bit errors which either preexisted or occurred
in course of operation. The logical operations we consider allow one to cary
out the vast majority of the steps in the quantum factoring algorithm. Thus,
our results help bring quantum factoring and other quantum computations closer
to reality
| [
{
"version": "v1",
"created": "Tue, 14 May 1996 19:05:38 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Zurek",
"Wojciech Hubert",
""
],
[
"Laflamme",
"Raymond",
""
]
] |
quant-ph/9605014 | Christopher Fuchs | Christopher A. Fuchs | Information Gain vs. State Disturbance in Quantum Theory | 5 pages LaTeX, Extended Abstract for PhysComp96, requires
pac96sty.tex | null | null | null | quant-ph | null | The engine that powers quantum cryptography is the principle that there are
no physical means for gathering information about the identity of a quantum
system's state (when it is known to be prepared in one of a set of
nonorthogonal states) without disturbing the system in a statistically
detectable way. This situation is often mistakenly described as a consequence
of the ``Heisenberg uncertainty principle.'' A more accurate account is that it
is a unique feature of quantum phenomena that rests ultimately on the Hilbert
space structure of the theory along with the fact that time evolutions for
isolated systems are unitary. In this paper I explore several aspects of the
``information / disturbance principle'' in an attempt to make it firmly
quantitative for both pure and mixed states. The final section briefly explores
the extent to which such a principle can be taken as a foundation for unitary
dynamics rather than as a consequence.
| [
{
"version": "v1",
"created": "Tue, 14 May 1996 22:27:58 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Fuchs",
"Christopher A.",
""
]
] |
quant-ph/9605015 | Tzanakis Konstantinos | Constantinos Tzanakis and Alkis P. Grecos | Generalized Moyal structures in phase space, kinetic equations and their
classical limit: I. General Formalism | 35 pages, TEX | null | null | null | quant-ph | null | Generalised Wigner and Weyl transformations of quantum operators are defined
and their properties, as well as those of the algebraic structure induced on
the phase-space are studied. Using such transformations, quantum linear
evolution equations are given a phase-space representation. In particular this
is done for the general kinetic equation of the Lindblad type. The resulting
expressions are better suited for the passage to the classical limit and for a
general comparison of classical and quantum systems. In this context a
preliminary discussion of a number of problems of kinetic theory of open
systems is given, whereas explicit applications are made in the next paper of
the series.
| [
{
"version": "v1",
"created": "Tue, 14 May 1996 20:57:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Tzanakis",
"Constantinos",
""
],
[
"Grecos",
"Alkis P.",
""
]
] |
quant-ph/9605016 | Tzanakis Konstantinos | C. Tzanakis, A. P. Grecos and P. Hatjimanolaki | Generalized Moyal structures in phase space, kinetic equations and their
classical limit: II. Applications to harmonic oscillator models | 30 pages, Tex | null | null | null | quant-ph | null | The formalism of generalized Wigner transformations developped in a previous
paper, is applied to kinetic equations of the Lindblad type for quantum
harmonic oscillator models. It is first applied to an oscillator coupled to an
equilibrium chain of other oscillators having nearest-neighbour interactions.
The kinetic equation is derived without using the so called rotating-wave
approximation. Then it is shown that the classical limit of the corresponding
phase-space equation is independent of the ordering of operators corresponding
to the inverse of the generalized Wigner transformation, provided the latter is
involutive. Moreover, this limit equation, which conserves the probabilistic
nature of the distribution function and obeys an H-theorem, coincides with the
kinetic equation for the corresponding classical system, which is derived
independently and is distinct from that usually obtained in the litterature and
not sharing the above properties. Finally the same formalism is applied to more
general model equations used in quantum optics and it is shown that the above
results remain unaltered.
| [
{
"version": "v1",
"created": "Tue, 14 May 1996 20:59:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Tzanakis",
"C.",
""
],
[
"Grecos",
"A. P.",
""
],
[
"Hatjimanolaki",
"P.",
""
]
] |
quant-ph/9605017 | Feng Pan | Wang Zhen (Dept. of Phys., Liaoning Normal University) | System and Its Uncertainty Quanta: Theory of General System (I) | 12 page, Latex | null | null | LNU-96016 | quant-ph gr-qc | null | The concept of uncertainty quanta for a general system is introduced and
applied to some important problems in physics and mathematics. EPR paradox
gives new clue to the further understanding of particle correlation which turns
out to be the nature of this world. Randomness in quantum mechanics,
statistical physics and chaos is integrated. A picture for a new kind of
mathematics is put forward.
| [
{
"version": "v1",
"created": "Wed, 15 May 1996 18:38:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zhen",
"Wang",
"",
"Dept. of Phys., Liaoning Normal University"
]
] |
quant-ph/9605018 | Feng Pan | Wang Zhen (Dept. of Phys., Liaoning Normal University) | Where Has Entropy Gone: Theory of General System (II) | 13 page, Latex | null | null | LNU-96017 | quant-ph gr-qc | null | A pair of symmetric expressions for the second law of thermodynamics is put
forward. The conservation and transfer of entropy is discussed and applied to
problems like biology, culture and life itself. A new explanation is given to
the cosmic expansion with the concept of diversity in this theory. The problem
of contingency and necessity is also discussed.
| [
{
"version": "v1",
"created": "Wed, 15 May 1996 18:41:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zhen",
"Wang",
"",
"Dept. of Phys., Liaoning Normal University"
]
] |
quant-ph/9605019 | Feng Pan | Wang Zhen (Dept. of Phys., Liaoning Normal University) | Quantum Cosmology: Theory of General System (III) | 18 page, Latex | null | null | LNU-96018 | quant-ph gr-qc | null | The concepts of the perfect system and degeneracy are introduced. A special
symmetry is found which is related to the entropy invariant. The inversion
relation of system is obtained which is used to give the oppsite direction of
time to classical sencond law of thermodanymics. The nature of time is
discussed together with causality relation. A new understanding of quantum
mechanics is put forward which describes a new picture of the world.
| [
{
"version": "v1",
"created": "Wed, 15 May 1996 18:44:39 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zhen",
"Wang",
"",
"Dept. of Phys., Liaoning Normal University"
]
] |
quant-ph/9605020 | I. T. Cheon | Il-Tong Cheon | Calculation of Electric Unit charge | 9 pages, revtex, no figure, compressed | null | null | null | quant-ph | null | Considering the stresses due to the vacuum fluctuation and the electric
charge loaded over the surface of a spherical cavity, we estimate the maximum
value of the charge. Since this value is independent of the cavity size and
parameter free, it is regarded as the electric unit charge. Our result is $Q=
1.55\times 10^{-19}$ Coulomb which implies the relevant fine structure constant
$\alpha=1/145.90$.
| [
{
"version": "v1",
"created": "Wed, 15 May 1996 05:48:36 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cheon",
"Il-Tong",
""
]
] |
quant-ph/9605021 | Andrew Steane | Andrew Steane (Clarendon Laboratory, Oxford University) | Simple Quantum Error Correcting Codes | Submitted to Phys. Rev. A. in May 1996. 21 pages, no figures. Further
information at http://eve.physics.ox.ac.uk/ASGhome.html | Phys.Rev.A54:4741,1996 | 10.1103/PhysRevA.54.4741 | St96c | quant-ph | null | Methods of finding good quantum error correcting codes are discussed, and
many example codes are presented. The recipe C_2^{\perp} \subseteq C_1, where
C_1 and C_2 are classical codes, is used to obtain codes for up to 16
information qubits with correction of small numbers of errors. The results are
tabulated. More efficient codes are obtained by allowing C_1 to have reduced
distance, and introducing sign changes among the code words in a systematic
manner. This systematic approach leads to single-error correcting codes for 3,
4 and 5 information qubits with block lengths of 8, 10 and 11 qubits
respectively.
| [
{
"version": "v1",
"created": "Wed, 15 May 1996 15:12:53 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Steane",
"Andrew",
"",
"Clarendon Laboratory, Oxford University"
]
] |
quant-ph/9605022 | Paul Benioff | Paul Benioff | Quantum Ballistic Evolution in Quantum Mechanics: Application to Quantum
Computers | 37 pages Latexwith 2 postscript figures tar+gzip+uuencoded, to be
published in Phys. Rev. A | null | 10.1103/PhysRevA.54.1106 | null | quant-ph | null | Quantum computers are important examples of processes whose evolution can be
described in terms of iterations of single step operators or their adjoints.
Based on this, Hamiltonian evolution of processes with associated step
operators $T$ is investigated here. The main limitation of this paper is to
processes which evolve quantum ballistically, i.e. motion restricted to a
collection of nonintersecting or distinct paths on an arbitrary basis. The main
goal of this paper is proof of a theorem which gives necessary and sufficient
conditions that T must satisfy so that there exists a Hamiltonian description
of quantum ballistic evolution for the process, namely, that T is a partial
isometry and is orthogonality preserving and stable on some basis. Simple
examples of quantum ballistic evolution for quantum Turing machines with one
and with more than one type of elementary step are discussed. It is seen that
for nondeterministic machines the basis set can be quite complex with much
entanglement present. It is also proved that, given a step operator T for an
arbitrary deterministic quantum Turing machine, it is decidable if T is stable
and orthogonality preserving, and if quantum ballistic evolution is possible.
The proof fails if T is a step operator for a nondeterministic machine. It is
an open question if such a decision procedure exists for nondeterministic
machines. This problem does not occur in classical mechanics.
| [
{
"version": "v1",
"created": "Wed, 15 May 1996 15:38:34 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Benioff",
"Paul",
""
]
] |
quant-ph/9605023 | David Meyer | David A. Meyer | Unitarity in one dimensional nonlinear quantum cellular automata | 32 pages, plain TeX, 3 PostScript figures included with epsf.tex
(ignore the under/overfull \vbox error messages) | null | null | null | quant-ph comp-gas hep-th nlin.CG | null | Unitarity of the global evolution is an extremely stringent condition on
finite state models in discrete spacetime. Quantum cellular automata, in
particular, are tightly constrained. In previous work we proved a simple No-go
Theorem which precludes nontrivial homogeneous evolution for linear quantum
cellular automata. Here we carefully define general quantum cellular automata
in order to investigate the possibility that there be nontrivial homogeneous
unitary evolution when the local rule is nonlinear. Since the unitary global
transition amplitudes are constructed from the product of local transition
amplitudes, infinite lattices require different treatment than periodic ones.
We prove Unitarity Theorems for both cases, expressing the equivalence in $1+1$
dimensions of global unitarity and certain sets of constraints on the local
rule, and then show that these constraints can be solved to give a variety of
multiparameter families of nonlinear quantum cellular automata. The Unitarity
Theorems, together with a Surjectivity Theorem for the infinite case, also
imply that unitarity is decidable for one dimensional cellular automata.
| [
{
"version": "v1",
"created": "Wed, 15 May 1996 23:20:34 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Meyer",
"David A.",
""
]
] |
quant-ph/9605024 | Asher Peres | Asher Peres | Quaternionic quantum interferometry | 7 pages LaTeX, to appear in "Quantum Interferometry" VCH Publishers
(1996), edited by F. De Martini | In "Quantum Interferometry" ed. by F. De Martini et al., (VCH
Publ., 1996) pp. 431-437 | null | null | quant-ph | null | If scattering amplitudes are ordinary complex numbers (not quaternions) there
is a universal algebraic relationship between the six coherent cross sections
of any three scatterers (taken singly and pairwise). A violation of this
relationship would indicate either that scattering amplitudes are quaternions,
or that the superposition principle fails. Some possible experimental tests
involve neutron interferometry, K_S-meson regeneration, and low energy
proton-proton scattering.
| [
{
"version": "v1",
"created": "Thu, 16 May 1996 10:03:57 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Peres",
"Asher",
""
]
] |
quant-ph/9605025 | Hoi Fung Chau | H. F. Chau and H.-K. Lo (IAS, Princeton) | How much does it cost to teleport? | 5 pages, extended abstract submitted to PHYSCOMP96 | null | null | IASSNS-HEP-96/51 | quant-ph | null | We show that the entropy of entanglement of a state characterizes its ability
to teleport. In particular, in order to teleport faithfully an unknown quantum
$N$-state, the two users must share an entangled state with at least $\log_2 N$
bits entropy of entanglement. We also note that the maximum capacity for a
mixed state ${\cal M}$ to teleport equals the maximum amount of entanglement
entropy that can be distilled out from ${\cal M}$. Our result, therefore,
provides an alternative interpretation for entanglement purification.
| [
{
"version": "v1",
"created": "Thu, 16 May 1996 19:25:41 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chau",
"H. F.",
"",
"IAS, Princeton"
],
[
"Lo",
"H. -K.",
"",
"IAS, Princeton"
]
] |
quant-ph/9605026 | Hoi Fung Chau | Hoi-Kwong Lo and H. F. Chau | Why quantum bit commitment and ideal quantum coin tossing are impossible | Replaced to give appropriate reference to D. Mayers' works and to fix
a crucial bug in the original proof of the impossibility of ideal quantum
coin tossing. Other minor changes are also made to clarify the discussion | null | null | IASSNS-HEP-96/50 | quant-ph | null | There had been well known claims of ``provably unbreakable'' quantum
protocols for bit commitment and coin tossing. However, we, and independently
Mayers, showed that all proposed quantum bit commitment (and therefore coin
tossing) schemes are, in principle, insecure because the sender, Alice, can
always cheat successfully by using an EPR-type of attack and delaying her
measurements. One might wonder if secure quantum bit commitment and coin
tossing protocols exist at all. Here we prove that an EPR-type of attack by
Alice will, in principle, break {\em any} realistic quantum bit commitment and
{\em ideal} coin tossing scheme. Therefore, provided that Alice has a quantum
computer and is capable of storing quantum signals for an arbitrary length of
time, all those schemes are insecure. Since bit commitment and coin tossing are
useful primitives for building up more sophisticated protocols such as
zero-knowledge proofs, our results cast very serious doubt on the security of
quantum cryptography in the so-called ``post-cold-war'' applications.
| [
{
"version": "v1",
"created": "Thu, 16 May 1996 19:28:22 GMT"
},
{
"version": "v2",
"created": "Thu, 22 Aug 1996 07:00:32 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Lo",
"Hoi-Kwong",
""
],
[
"Chau",
"H. F.",
""
]
] |
quant-ph/9605027 | Serge Massar | S. Massar | Applications of the Complex Geometric "Phase" for Meta-stable Systems | RevTeX, 6 pages | Phys.Rev. A54 (1996) 4770-4774 | 10.1103/PhysRevA.54.4770 | TAUP 2340-96 | quant-ph | null | Garrison and Wright showed that upon undergoing cyclic quantum evolution a
meta-stable state acquires both a geometric phase and a geometric decay
probability. This is described by a complex geometric ``phase'' associated with
the cyclic evolution of two states and is closely related to the two state
formalism developed by Aharonov et al.. Applications of the complex geometric
phase to the Born--Oppenheimer approximation and the Aharonov--Bohm effect are
considered. A simple experiment based on the optical properties of absorbing
birefringent crystals is proposed.
| [
{
"version": "v1",
"created": "Sun, 19 May 1996 13:33:29 GMT"
},
{
"version": "v2",
"created": "Tue, 28 May 1996 11:32:03 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Massar",
"S.",
""
]
] |
quant-ph/9605028 | Chi-Keung Chow | C.K. Au, Chi-Keung Chow and Chong-Sun Chu | Perturbative Scattering Phase Shifts in One-Dimension: Closed-form
Results | 10 pages in REVTeX | Phys.Lett. A226 (1997) 327-331 | 10.1016/S0375-9601(97)00006-6 | CLNS 96/1408, LBL-38656, UCB-96/17 | quant-ph | null | A simple closed form expression is obtained for the scattering phase shift
perturbatively to any given order in effective one-dimensional problems. The
result is a hierarchical scheme, expressible in quadratures, requiring only
knowledge of the zeroth order solution and the perturbation potential.
| [
{
"version": "v1",
"created": "Mon, 20 May 1996 19:40:40 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Au",
"C. K.",
""
],
[
"Chow",
"Chi-Keung",
""
],
[
"Chu",
"Chong-Sun",
""
]
] |
quant-ph/9605029 | Li-Hua Yu | Li Hua Yu | Exponential Decay of Wavelength in a Dissipative System | 12 pages, 3 Postscript figures, uses standard latex | Phys. Lett. A 202 (1995) 167 | 10.1016/0375-9601(95)00274-7 | null | quant-ph | null | Applying a technique developed in a recent work[1] to calculate wavefunction
evolution in a dissipative system with Ohmic friction, we show that the
wavelength of the wavefunction decays exponentially, while the Brownian motion
width gradually increases. In an interference experiment, when these two
parameters become equal, the Brownian motion erases the fringes, the system
thus approaches classical limit. We show that the wavelength decay is an
observable phenomenon.
| [
{
"version": "v1",
"created": "Mon, 20 May 1996 15:04:27 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Yu",
"Li Hua",
""
]
] |
quant-ph/9605030 | Ken-ich Kuga | Ken'ichi Kuga (Dept. Math. and Info. Chiba Univ. Japan) | Proposing Quantum Relativity and Finite Program | 19 pages | null | null | 96-05 | quant-ph | null | We show monistic realism consistent with quantum theory may be restored by
extending the essential idea of relativity in such a way that every physical
system is eligible, in principle, for an observing system. As a result, a
common logical basis of quantum theory and relativity, and hence that of modern
quantum gauge theories emerges. Supported by this logic, we propose to
reconstruct physics solely from finite EPR complexes. Along the discussion an
interpretation of String theory is provided. Aside from conceptual appeal and a
priori mathematical finiteness, our point of view drastically explains in a
rather trivial fashion some basic problems which are otherwise unlikely to be
resolved: Namely, the increase of entropy in macro scales, and the issue of the
cosmic coincidence. In fact, the expansion of the universe may be given a
tautological reasoning in our context.
| [
{
"version": "v1",
"created": "Wed, 22 May 1996 06:03:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kuga",
"Ken'ichi",
"",
"Dept. Math. and Info. Chiba Univ. Japan"
]
] |
quant-ph/9605031 | null | David P. DiVincenzo (IBM), Peter W. Shor (AT&T) | Fault-Tolerant Error Correction with Efficient Quantum Codes | 12 pages REVTeX, 1 ps figure included. Minor additions and revisions | null | 10.1103/PhysRevLett.77.3260 | null | quant-ph | null | We exhibit a simple, systematic procedure for detecting and correcting errors
using any of the recently reported quantum error-correcting codes. The
procedure is shown explicitly for a code in which one qubit is mapped into
five. The quantum networks obtained are fault tolerant, that is, they can
function successfully even if errors occur during the error correction. Our
construction is derived using a recently introduced group-theoretic framework
for unifying all known quantum codes.
| [
{
"version": "v1",
"created": "Wed, 22 May 1996 18:11:19 GMT"
},
{
"version": "v2",
"created": "Fri, 23 Aug 1996 15:15:26 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"DiVincenzo",
"David P.",
"",
"IBM"
],
[
"Shor",
"Peter W.",
"",
"AT&T"
]
] |
quant-ph/9605032 | Michael Martin Nieto | Michael Martin Nieto | Functional Forms for the Squeeze and the Time-Displacement Operators | 10 pages, LaTeX | Quant.Semiclass.Opt. 8 (1996) 1061 | 10.1088/1355-5111/8/5/011 | LA-UR-96-1596 | quant-ph | null | Using Baker-Campbell-Hausdorff relations, the squeeze and harmonic-oscillator
time-displacement operators are given in the form $\exp[\delta I] \exp[\alpha
(x^2)]\exp[\beta(x\partial)] \exp[\gamma (\partial)^2]$, where $\alpha$,
$\beta$, $\gamma$, and $\delta$ are explicitly determined. Applications are
discussed.
| [
{
"version": "v1",
"created": "Wed, 22 May 1996 22:04:59 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Nieto",
"Michael Martin",
""
]
] |
quant-ph/9605033 | Hagen Kleinert | H. Kleinert and S. Thoms | Resummation of anisotropic quartic oscillator. Crossover from
anisotropic to isotropic large-order behavior | Paper and .eps files. Author Information at
http://www.physik.fu-berlin.de/~kleinert/institution.html . Paper at
http://www.physik.fu-berlin.de/~kleinert/kleiner_re243/preprint.html | null | 10.1103/PhysRevA.55.915 | null | quant-ph | null | We present an approximative calculation of the ground-state energy for the
anisotropic anharmonic oscillator Using an instanton solution of the isotropic
action $\delta = 0$, we obtain the imaginary part of the ground-state energy
for small negative $g$ as a series expansion in the anisotropy parameter
$\delta$. From this, the large-order behavior of the $g$-expansions
accompanying each power of $\delta$ are obtained by means of a dispersion
relation in $g$. These $g$-expansions are summed by a Borel transformation,
yielding an approximation to the ground-state energy for the region near the
isotropic limit. This approximation is found to be excellent in a rather wide
region of $\delta$ around $\delta = 0$. Special attention is devoted to the
immediate vicinity of the isotropic point. Using a simple model integral we
show that the large-order behavior of an $\delta$-dependent series expansion in
$g$ undergoes a crossover from an isotropic to an anisotropic regime as the
order $k$ of the expansion coefficients passes the value $k_{{\rm cross} \sim
1/ |{\delta}|$.
| [
{
"version": "v1",
"created": "Thu, 23 May 1996 06:49:35 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Kleinert",
"H.",
""
],
[
"Thoms",
"S.",
""
]
] |
quant-ph/9605034 | Gilles Brassard | Michel Boyer (Universite de Montreal), Gilles Brassard (Universite de
Montreal), Peter Hoeyer (Odense University) and Alain Tapp (Universite de
Montreal) | Tight bounds on quantum searching | 8 pages, LaTeX2e, PhysComp 96 submission | Fortsch.Phys.46:493-506,1998 | 10.1002/(SICI)1521-3978(199806)46:4/5<493::AID-PROP493>3.0.CO;2-P | null | quant-ph | null | We provide a tight analysis of Grover's recent algorithm for quantum database
searching. We give a simple closed-form formula for the probability of success
after any given number of iterations of the algorithm. This allows us to
determine the number of iterations necessary to achieve almost certainty of
finding the answer. Furthermore, we analyse the behaviour of the algorithm when
the element to be found appears more than once in the table and we provide a
new algorithm to find such an element even when the number of solutions is not
known ahead of time. Using techniques from Shor's quantum factoring algorithm
in addition to Grover's approach, we introduce a new technique for approximate
quantum counting, which allows to estimate the number of solutions. Finally we
provide a lower bound on the efficiency of any possible quantum database
searching algorithm and we show that Grover's algorithm nearly comes within a
factor 2 of being optimal in terms of the number of probes required in the
table.
| [
{
"version": "v1",
"created": "Thu, 23 May 1996 18:26:36 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Boyer",
"Michel",
"",
"Universite de Montreal"
],
[
"Brassard",
"Gilles",
"",
"Universite de\n Montreal"
],
[
"Hoeyer",
"Peter",
"",
"Odense University"
],
[
"Tapp",
"Alain",
"",
"Universite de\n Montreal"
]
] |
quant-ph/9605035 | Gilles Brassard | Gilles Brassard (Universite de Montreal) | Teleportation as a quantum computation | 3 pages, LaTeX2e, PhysComp 96 submission | Physica D120 (1998) 43-47 | 10.1016/S0167-2789(98)00043-8 | null | quant-ph | null | An explicit quantum circuit is given to implement quantum teleportation. This
circuit makes teleportation straightforward to anyone who believes that quantum
computation is a reasonable proposition. It could also be genuinely used inside
a quantum computer if teleportation is needed to move quantum information
around. An unusual feature of this circuit is that there are points in the
computation at which the quantum information can be completely disrupted by a
measurement (or some types of interaction with the environment) without ill
effects: the same final result is obtained whether or not these measurements
takes place.
| [
{
"version": "v1",
"created": "Thu, 23 May 1996 20:57:18 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Brassard",
"Gilles",
"",
"Universite de Montreal"
]
] |
quant-ph/9605036 | Stephen Trentalange | S. Trentalange and S.U. Pandey | Bose-Einstein Correlations and Sonoluminescence | Latex File, 8 pages, Postscript file with 2 figs. attached | null | 10.1121/1.415435 | null | quant-ph | null | Sonoluminescence may be studied in detail by intensity correlations among the
emitted photons. As an example, we discuss an experiment to measure the size of
the light-emitting region by the Hanbury Brown-Twiss effect. We show that
single bubble sonoluminescence is almost ideally suited for study by this
method and that plausible values for the physical parameters are within easy
experimental reach. A sequence of two and higher order photon correlation
experiments is outlined.
| [
{
"version": "v1",
"created": "Mon, 27 May 1996 20:32:39 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Trentalange",
"S.",
""
],
[
"Pandey",
"S. U.",
""
]
] |
quant-ph/9605037 | Oliver Rudolph | Oliver Rudolph | On the Consistent Effect Histories Approach to Quantum Mechanics | LaTeX 2.09 version replaced by LaTeX2e version, minor changes | J.Math.Phys. 37 (1996) 5368-5379 | 10.1063/1.531709 | DESY 96-097 | quant-ph | null | A formulation of the consistent histories approach to quantum mechanics in
terms of generalized observables (POV measures) and effect operators is
provided. The usual notion of `history' is generalized to the notion of `effect
history'. The space of effect histories carries the structure of a D-poset.
Recent results of J.D. Maitland Wright imply that every decoherence functional
defined for ordinary histories can be uniquely extended to a bi-additive
decoherence functional on the space of effect histories. Omnes' logical
interpretation is generalized to the present context. The result of this work
considerably generalizes and simplifies the earlier formulation of the
consistent effect histories approach to quantum mechanics communicated in a
previous work of this author.
| [
{
"version": "v1",
"created": "Tue, 28 May 1996 11:33:25 GMT"
},
{
"version": "v2",
"created": "Fri, 7 Jun 1996 11:39:47 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Rudolph",
"Oliver",
""
]
] |
quant-ph/9605038 | Michal Horodecki | Michal Horodecki, Pawel Horodecki and Ryszard Horodecki | Separability of Mixed States: Necessary and Sufficient Conditions | Revtex, 13 pages, replaced with minor typos corrected and some
examples added | null | 10.1016/S0375-9601(96)00706-2 | null | quant-ph | null | We provide necessary and sufficient conditions for separability of mixed
states. As a result we obtain a simple criterion of separability for $2\times2$
and $2\times3$ systems. Here, the positivity of the partial transposition of a
state is necessary and sufficient for its separability. However, it is not the
case in general. Some examples of mixtures which demonstrate the utility of the
criterion are considered.
| [
{
"version": "v1",
"created": "Tue, 28 May 1996 16:00:37 GMT"
},
{
"version": "v2",
"created": "Wed, 26 Jun 1996 14:58:45 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Horodecki",
"Michal",
""
],
[
"Horodecki",
"Pawel",
""
],
[
"Horodecki",
"Ryszard",
""
]
] |
quant-ph/9605039 | Nicolas Cerf | Nicolas J. Cerf, Chris Adami (California Institute of Technology) | Quantum Information Theory of Entanglement and Measurement | 26 pages with 6 figures. Expanded version of PhysComp'96 contribution | Physica D120 (1998) 62-81 | 10.1016/S0167-2789(98)00045-1 | KRL MAP-199 | quant-ph | null | We present a quantum information theory that allows for a consistent
description of entanglement. It parallels classical (Shannon) information
theory but is based entirely on density matrices (rather than probability
distributions) for the description of quantum ensembles. We find that quantum
conditional entropies can be negative for entangled systems, which leads to a
violation of well-known bounds in Shannon information theory. Such a unified
information-theoretic description of classical correlation and quantum
entanglement clarifies the link between them: the latter can be viewed as
``super-correlation'' which can induce classical correlation when considering a
tripartite or larger system. Furthermore, negative entropy and the associated
clarification of entanglement paves the way to a natural information-theoretic
description of the measurement process. This model, while unitary and causal,
implies the well-known probabilistic results of conventional quantum mechanics.
It also results in a simple interpretation of the Kholevo theorem limiting the
accessible information in a quantum measurement.
| [
{
"version": "v1",
"created": "Wed, 29 May 1996 01:11:25 GMT"
},
{
"version": "v2",
"created": "Tue, 21 Jan 1997 03:22:31 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Cerf",
"Nicolas J.",
"",
"California Institute of Technology"
],
[
"Adami",
"Chris",
"",
"California Institute of Technology"
]
] |
quant-ph/9605040 | Hong Seung Pyo | S. P. Hong, H. Doh, and S. H. Suck Salk (Pohang University of Science
and Technology, Korea) | Berry Phases with Real Hamiltonians With and Without a Many-body System
as a Background | 4 pages RevTex, uses epsf,twocolumn, 3 embedded postscript figures,
submitted to PRL, acknowledgement appended | null | null | null | quant-ph cond-mat | null | We present both the gauge theoretic description and the numerical
calculations of the Berry phases with the real eigenstates, involving one with
a many-body system as a background and the other with no such background. We
demonstrate that for the former the sign of the Berry phase factor for a spin
$\f{1}{2}$ particle (hole) coupled to a slow subsystem (phonon) depends on both
the strength of electron correlations and the characteristics of the closed
paths, unlike the cases for the latter.
| [
{
"version": "v1",
"created": "Wed, 29 May 1996 07:25:50 GMT"
},
{
"version": "v2",
"created": "Tue, 11 Jun 1996 02:32:17 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Hong",
"S. P.",
"",
"Pohang University of Science\n and Technology, Korea"
],
[
"Doh",
"H.",
"",
"Pohang University of Science\n and Technology, Korea"
],
[
"Salk",
"S. H. Suck",
"",
"Pohang University of Science\n and Technology, Korea"
]
] |
quant-ph/9605041 | Isar Aurelian | A. Isar, A. Sandulescu and W.Scheid | Phase Space Representation for Open Quantum Systems within the Lindblad
Theory | 19 pages, Latex, accepted for publication in Int. J. Mod. Phys. B | Int.J.Mod.Phys.B10:2767,1996 | 10.1142/S0217979296001240 | FT-414-1996 | quant-ph | null | The Lindblad master equation for an open quantum system with a Hamiltonian
containing an arbitrary potential is written as an equation for the Wigner
distribution function in the phase space representation. The time derivative of
this function is given by a sum of three parts: the classical one, the quantum
corrections and the contribution due to the opening of the system. In the
particular case of a harmonic oscillator, quantum corrections do not exist.
| [
{
"version": "v1",
"created": "Wed, 29 May 1996 11:10:51 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Isar",
"A.",
""
],
[
"Sandulescu",
"A.",
""
],
[
"Scheid",
"W.",
""
]
] |
quant-ph/9605042 | Arvind | Arvind (IISc Bangalore), K. S. Mallesh (Univ. of Mysore) and N.
Mukunda (IISc Bangalore) | A generalized Pancharatnam geometric phase formula for three level
systems | 12 pages, Revtex, one figure, epsf used for figure insertion | J.Phys.A30:2417-2431,1997 | 10.1088/0305-4470/30/7/021 | null | quant-ph | null | We describe a generalisation of the well known Pancharatnam geometric phase
formula for two level systems, to evolution of a three-level system along a
geodesic triangle in state space. This is achieved by using a recently
developed generalisation of the Poincare sphere method, to represent pure
states of a three-level quantum system in a convenient geometrical manner. The
construction depends on the properties of the group $SU(3)\/$ and its
generators in the defining representation, and uses geometrical objects and
operations in an eight dimensional real Euclidean space. Implications for an
n-level system are also discussed.
| [
{
"version": "v1",
"created": "Wed, 29 May 1996 19:12:19 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Arvind",
"",
"",
"IISc Bangalore"
],
[
"Mallesh",
"K. S.",
"",
"Univ. of Mysore"
],
[
"Mukunda",
"N.",
"",
"IISc Bangalore"
]
] |
quant-ph/9605043 | Lov K. Grover | Lov K. Grover (Bell Labs, Murray Hill NJ) | A fast quantum mechanical algorithm for database search | 8 pages, single postscript file. This is an updated version of a
paper that was originally presented at STOC 1996. The algorithm is the same;
however, the proof has been simplified by using a new interpretation termed
"inversion about average." Also a few recently discovered insights have been
added. Journal Ref.: Proceedings, 28th Annual ACM Symposium on the Theory of
Computing (STOC), May 1996, pages 212-219 | null | null | null | quant-ph | null | Imagine a phone directory containing N names arranged in completely random
order. In order to find someone's phone number with a 50% probability, any
classical algorithm (whether deterministic or probabilistic) will need to look
at a minimum of N/2 names. Quantum mechanical systems can be in a superposition
of states and simultaneously examine multiple names. By properly adjusting the
phases of various operations, successful computations reinforce each other
while others interfere randomly. As a result, the desired phone number can be
obtained in only O(sqrt(N)) steps. The algorithm is within a small constant
factor of the fastest possible quantum mechanical algorithm.
| [
{
"version": "v1",
"created": "Wed, 29 May 1996 19:09:06 GMT"
},
{
"version": "v2",
"created": "Thu, 30 May 1996 19:38:36 GMT"
},
{
"version": "v3",
"created": "Tue, 19 Nov 1996 17:54:17 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Grover",
"Lov K.",
"",
"Bell Labs, Murray Hill NJ"
]
] |
quant-ph/9605044 | Dominic Mayers | Dominic Mayers (Princeton University) | Unconditionally secure quantum bit commitment is impossible | 4 pages, revtex. Journal version replacing the version published in
the proceedings of PhysComp96. This is a significantly improved version which
emphasis the generality of the result | null | 10.1103/PhysRevLett.78.3414 | null | quant-ph | null | The claim of quantum cryptography has always been that it can provide
protocols that are unconditionally secure, that is, for which the security does
not depend on any restriction on the time, space or technology available to the
cheaters. We show that this claim does not hold for any quantum bit commitment
protocol. Since many cryptographic tasks use bit commitment as a basic
primitive, this result implies a severe setback for quantum cryptography. The
model used encompasses all reasonable implementations of quantum bit commitment
protocols in which the participants have not met before, including those that
make use of the theory of special relativity.
| [
{
"version": "v1",
"created": "Thu, 30 May 1996 20:43:57 GMT"
},
{
"version": "v2",
"created": "Tue, 14 Jan 1997 21:48:12 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Mayers",
"Dominic",
"",
"Princeton University"
]
] |
quant-ph/9605045 | Andrea Begliuomini | Andrea Begliuomini and Luciano Bracci | The tunneling time for a wave packet as measured with a physical clock | 12 pages in REVTeX, submitted to Il Nuovo Cimento | Nuovo Cim. B112 (1997) 603-612 | null | IFUP-TH 96-45 | quant-ph | null | We study the time required for a wave packet to tunnel beyond a square
barrier, or to be reflected, by envisaging a physical clock which ticks only
when the particle is within the barrier region. The clock consists in a
magnetic moment initially aligned with the $x$ axis which in the barrier region
precesses around a constant magnetic field aligned with the $z$ axis, the
motion being in the $y$ direction. The values of the $x$ and $y$ components of
the magnetic moment beyond or in front of the barrier allow to assign a
tunneling or reflection time to every fraction of the packet which emerges from
the barrier and to calculate tunneling times $\tau_{\rm T,x}$ and $\tau_{\rm
T,y}$ and reflection times $\tau_{\rm R,x}$ and $\tau_{\rm R,y}$. The times
$\tau_{\rm T,x}$ and $\tau_{\rm T,y}$ ($\tau_{\rm R,x}$ and $\tau_{\rm R,y}$)
are remarkably equal, and independent of the initial position (in front of the
barrier) of the packet.
| [
{
"version": "v1",
"created": "Sat, 1 Jun 1996 10:56:20 GMT"
},
{
"version": "v2",
"created": "Sat, 8 Jun 1996 08:50:48 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Begliuomini",
"Andrea",
""
],
[
"Bracci",
"Luciano",
""
]
] |
quant-ph/9605046 | Hyeong-Chan Kim | Hyeong-Chan Kim, Min-Ho Lee, Jeong-Young Ji, and Jae Kwan Kim (KAIST) | Heisenberg-picture approach to the exact quantum motion of a
time-dependent forced harmonic oscillator | 15 pages, two eps files, to appear in Phys. Rev. A 53 (6) (1996) | Phys. Rev. A, 53 (1996) 3767. | 10.1103/PhysRevA.53.3767 | KAIST-CHEP-96/01 | quant-ph | null | In the Heisenberg picture, the generalized invariant and exact quantum
motions are found for a time-dependent forced harmonic oscillator. We find the
eigenstate and the coherent state of the invariant and show that the
dispersions of these quantum states do not depend on the external force. Our
formalism is applied to several interesting cases.
| [
{
"version": "v1",
"created": "Fri, 12 May 1995 03:03:50 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Kim",
"Hyeong-Chan",
"",
"KAIST"
],
[
"Lee",
"Min-Ho",
"",
"KAIST"
],
[
"Ji",
"Jeong-Young",
"",
"KAIST"
],
[
"Kim",
"Jae Kwan",
"",
"KAIST"
]
] |
quant-ph/9605047 | C. J. Dove | Chris Dove and Euan J. Squires | A Local Model of Explicit Wavefunction Collapse | 18 pages with 8 figures, LaTeX | null | null | DTP-96-23 | quant-ph | null | A model of spontaneous wavefunction collapse, which is explicitly local and
Lorentz-invariant, is defined. Some of the predictions of the model for
specific experimental situations are derived. It is shown that, although
incompatible collapses, e.g. on opposite sides of an EPR-type of experiment,
can occur, they will not persist in time and that eventually only compatible
results will be obtained. The probabilities of particular results, however,
will in general not agree with the predictions of quantum theory. We argue that
it is unlikely that the deviations would have been seen in any experiment yet
performed.
| [
{
"version": "v1",
"created": "Fri, 31 May 1996 14:55:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Dove",
"Chris",
""
],
[
"Squires",
"Euan J.",
""
]
] |
quant-ph/9606001 | Hagen Kleinert | H. Kleinert | Classical and Fluctuating Paths in Spaces with Curvature and Torsion | Lecture presented at the 5th INTERNATIONAL CONFERENCE ON PATH
INTEGRALS FROM meV TO MeV, Dubna, May 27-31, 1996 For more info, see
http://www.physik.fu-berlin.de/~kleinert/ | null | null | null | quant-ph | null | This conference talk elaborates on a recently discovered mapping procedure by
which classical orbits and path integrals for the motion of a point particle in
flat space can be transformed correctly into those in curved space. This
procedure evolved from well established methods in the theory of plastic
deformations where crystals with defects are described mathematically by
applying nonholonomic coordinate transformations to ideal crystals. In the
context of time-sliced path integrals, there seems to exists a quantum
equivalence principle which determines the measures of fluctating orbits in
spaces with curvature and torsion. The nonholonomic transformations produce a
nontrivial Jacobian in the path measure which in a curved space produces
an additional term proportional to the curvature scalar canceling a similar
term found earlier by DeWitt from a naive formulation of Feynman's time-sliced
path integral. This cancelation is important in correctly describing
semiclassically and quantum mechanically various systems such as the hydrogen
atom, a particle on the surface of a sphere, and a spinning top. It is also
indispensible for the process of bosonization, by which Fermi particles are
redescribed in terms of Bose fields.
| [
{
"version": "v1",
"created": "Mon, 3 Jun 1996 11:27:39 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Aug 1996 06:46:08 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Kleinert",
"H.",
""
]
] |
quant-ph/9606002 | null | Lars M. Johansen (University of Oslo) | Bell's inequality for the Mach-Zehnder interferometer | 4 pages, Revtex, 2 postscript figures, to appear in Phys. Lett. A | Phys.Lett. A219 (1996) 15-18 | 10.1016/0375-9601(96)00437-9 | null | quant-ph | null | We show that no local, hidden variable model can be given for two-channel
states exhibiting both a sufficiently high interference visibility and a
sufficient degree of anticorrelation in a Mach-Zehnder interferometer.
| [
{
"version": "v1",
"created": "Tue, 4 Jun 1996 17:49:42 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Johansen",
"Lars M.",
"",
"University of Oslo"
]
] |
quant-ph/9606003 | Dominic Mayers | Dominic Mayers (Universite de Montreal) | Quantum Key Distribution and String Oblivious Transfer in Noisy Channels | 15 pages, no figure, to be published at Crypto 96 | null | null | null | quant-ph | null | We prove the unconditional security of a quantum key distribution (QKD)
protocol on a noisy channel against the most general attack allowed by quantum
physics. We use the fact that in a previous paper we have reduced the proof of
the unconditionally security of this QKD protocol to a proof that a
corresponding Quantum String Oblivious Transfer (String-QOT) protocol would be
unconditionally secure against Bob if implemented on top of an unconditionally
secure bit commitment scheme. We prove a lemma that extends a security proof
given by Yao for a (one bit) QOT protocol to this String-QOT protocol. This
result and the reduction mentioned above implies the unconditional security of
our QKD protocol despite our previous proof that unconditionally secure bit
commitment schemes are impossible.
| [
{
"version": "v1",
"created": "Tue, 4 Jun 1996 18:13:07 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Mayers",
"Dominic",
"",
"Universite de Montreal"
]
] |
quant-ph/9606004 | Robert B. Griffiths | Robert B. Griffiths (Carnegie-Mellon Univ.,Pittsburgh) | Consistent Histories and Quantum Reasoning | Latex, 31 pages | null | 10.1103/PhysRevA.54.2759 | null | quant-ph | null | A system of quantum reasoning for a closed system is developed by treating
non-relativistic quantum mechanics as a stochastic theory. The sample space
corresponds to a decomposition, as a sum of orthogonal projectors, of the
identity operator on a Hilbert space of histories. Provided a consistency
condition is satisfied, the corresponding Boolean algebra of histories, called
a {\it framework}, can be assigned probabilities in the usual way, and within a
single framework quantum reasoning is identical to ordinary probabilistic
reasoning. A refinement rule, which allows a probability distribution to be
extended from one framework to a larger (refined) framework, incorporates the
dynamical laws of quantum theory. Two or more frameworks which are incompatible
because they possess no common refinement cannot be simultaneously employed to
describe a single physical system.
| [
{
"version": "v1",
"created": "Tue, 4 Jun 1996 21:31:35 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Griffiths",
"Robert B.",
"",
"Carnegie-Mellon Univ.,Pittsburgh"
]
] |
quant-ph/9606005 | Erica R. Nakano | E. R. Takano Natti, A. F. R de Toledo Piza | Mean Field and Collisional Dynamics of Interacting Fermion-Boson systems
in a Soluble Model | 18 pages, latex, 2 postscript figures, some literary changes, a few
notation corrections | Physica A236 (1997) 321 | 10.1016/S0378-4371(96)00371-8 | Physica A236, 321-334 (1997) | quant-ph atom-ph math-ph math.MP nlin.SI nucl-th solv-int | null | A general time-dependent projection technique is applied to the study of the
dynamics of quantum correlations in a system consisting of interacting
fermionic and bosonic subsystems, described by the Jaynes-Cummings Hamiltonian.
The amplitude modulation of the Rabi oscillations which occur for a strong,
coherent initial bosonic field is obtained from the spin intrinsic
depolarization resulting from collisional corrections to the mean-field
approximation.
| [
{
"version": "v1",
"created": "Tue, 4 Jun 1996 21:46:25 GMT"
},
{
"version": "v2",
"created": "Fri, 25 Apr 1997 21:59:34 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Natti",
"E. R. Takano",
""
],
[
"Piza",
"A. F. R de Toledo",
""
]
] |
quant-ph/9606006 | Laszlo E. Szabo | Laszlo E. Szabo (Eotvos University, Budapest) | Is there anything non-classical? | Introduction and References are rewritten + corrections in Fig. 5, 21
pages, LaTeX, 5 ps-pictures | null | null | null | quant-ph | null | It is argued that quantum logic and quantum probability theory are
fascinating mathematical theories but without any relevance to our real world.
| [
{
"version": "v1",
"created": "Wed, 5 Jun 1996 12:01:37 GMT"
},
{
"version": "v2",
"created": "Mon, 12 Aug 1996 13:01:16 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Szabo",
"Laszlo E.",
"",
"Eotvos University, Budapest"
]
] |
quant-ph/9606007 | dr. W. M. de Muynck | Willem M. de Muynck (Eindhoven University of Technology) | Wigner Distributions and the Joint Measurement of Incompatible
Observables | 8 pages, latex, 3 figures | null | null | null | quant-ph | null | A theory of joint nonideal measurement of incompatible observables is used in
order to assess the relative merits of quantum tomography and certain
measurements of generalized observables, with respect to completeness of the
obtained information. A method is studied for calculating a Wigner distribution
from the joint probability distribution obtained in a joint measurement.
| [
{
"version": "v1",
"created": "Fri, 7 Jun 1996 14:01:07 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"de Muynck",
"Willem M.",
"",
"Eindhoven University of Technology"
]
] |
quant-ph/9606008 | T. Gruner | Toralf Gruner and Dirk-Gunnar Welsch | Photon tunneling through absorbing dielectric barriers | 17 pages LaTeX, 9 figures (PS) included | null | 10.1016/S0030-4018(96)00584-6 | FSUJ TPI QO-07/96 | quant-ph | null | Using a recently developed formalism of quantization of radiation in the
presence of absorbing dielectric bodies, the problem of photon tunneling
through absorbing barriers is studied. The multilayer barriers are described in
terms of multistep complex permittivities in the frequency domain which satisfy
the Kramers--Kronig relations. From the resulting input--output relations it is
shown that losses in the layers may considerably change the photon tunneling
times observed in two-photon interference experiments. It is further shown that
for sufficiently large numbers of layers interference fringes are observed that
cannot be related to a single traversal time.
| [
{
"version": "v1",
"created": "Tue, 11 Jun 1996 17:46:06 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Gruner",
"Toralf",
""
],
[
"Welsch",
"Dirk-Gunnar",
""
]
] |
quant-ph/9606009 | David Politzer | H. David Politzer | Condensate fluctuations of a trapped, ideal Bose gas | 16 pages (REVTeX) plus 4 figures (ps), revision includes brief
comparison of repulsive-interaction vs. fixed-N fluctuation damping. To be
published in Phys. Rev. A | Phys.Rev.A54:5048-5054,1996 | 10.1103/PhysRevA.54.5048 | CALT-68-2061 | quant-ph | null | For a non-self-interacting Bose gas with a fixed, large number of particles
confined to a trap, as the ground state occupation becomes macroscopic, the
condensate number fluctuations remain micrscopic. However, this is the only
significant aspect in which the grand canonical description differs from
canonical or microcanonical in the thermodynamic limit. General arguments and
estimates including some vanishingly small quantities are compared to explicit,
fixed-number calculations for 10^2 to 10^6 particles.
| [
{
"version": "v1",
"created": "Tue, 11 Jun 1996 19:21:40 GMT"
},
{
"version": "v2",
"created": "Wed, 4 Sep 1996 23:47:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Politzer",
"H. David",
""
]
] |
quant-ph/9606010 | S. Braunstein | Samuel L. Braunstein (Universitat Ulm, Abteilung Quantenphysik, Ulm,
Germany) | Quantum teleportation circuitry | This paper is withdrawn as it is equivalent to the paper
quant-ph/9605035 by Gilles Brassard | null | null | null | quant-ph | null | This paper is withdrawn as it is equivalent to the paper quant-ph/9605035 by
Gilles Brassard.
| [
{
"version": "v1",
"created": "Wed, 12 Jun 1996 15:44:25 GMT"
},
{
"version": "v2",
"created": "Sat, 15 Jun 1996 13:46:10 GMT"
}
] | 2008-02-03T00:00:00 | [
[
"Braunstein",
"Samuel L.",
"",
"Universitat Ulm, Abteilung Quantenphysik, Ulm,\n Germany"
]
] |
quant-ph/9606011 | Ary Espinoza Muller | Ary W. Espinosa M\"uller and Adelio R. Matamala V\'asquez | Algebraic Formulation of the Operatorial Perturbation Theory. Part I | plain LATEX, submitted to Phys. Rev. A | null | null | DFUDEC-9603 | quant-ph | null | A new totally algebraic formalism based on general, abstract ladder operators
has been proposed. This approach heavily grounds in the superoperator formalism
of Primas. However it is necessary to introduce many improvements in his
formalism. In this regard, it has been introduced a new set of superoperators
featured by their algebraic structure. Also, two lemmas and one theorem have
been developed in order to algebraically reformulate the theory on more
rigorous grounds. Finally, we have been able to build a coherent and
self-contained formalism independent on any matricial representation , removing
in this way the degeneracy problem .
| [
{
"version": "v1",
"created": "Wed, 12 Jun 1996 21:01:04 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Müller",
"Ary W. Espinosa",
""
],
[
"Vásquez",
"Adelio R. Matamala",
""
]
] |
quant-ph/9606012 | Michael Nielsen | M. A. Nielsen (University of New Mexico) | The entanglement fidelity and quantum error correction | 4 pages, RevTeX, no figures | null | null | null | quant-ph | null | Two new expressions for the entanglement fidelity recently introduced by
Schumacher (LANL e-print quant-ph/9604023, to appear in Phys. Rev. A) are
derived. These expressions show that it is the entanglement fidelity which must
be maximized when performing error correction on qubits for quantum computers,
not the fidelity, which is the most-often used generalization of the
probability for storing a qubit correctly.
| [
{
"version": "v1",
"created": "Thu, 13 Jun 1996 19:54:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Nielsen",
"M. A.",
"",
"University of New Mexico"
]
] |
quant-ph/9606013 | Ary Espinoza Muller | Ary W. Espinosa--M\"uller and Adelio R. Matamala V\'asquez | Algebraic Formulation of the Operatorial Perturbation Theory. Part 2.
Aplications | plain LATEX; submitted to Phys. Rev. A | null | null | DFUDEC-9604 | quant-ph | null | The algebraic approach to operator perturbation method has been applied to
two quantum--mechanical systems ``The Stark Effect in the Harmonic Oscillator''
and ``The Generalized Zeeman Effect''. To that end, two realizations of the
superoperators involved in the formalism have been carried out. The first of
them has been based on the Heisenberg--Dirac algebra of $\hat{a}^\dagger$,
$\hat{a}$, $\hat{1}$ operators, the second one has been based in the angular
momemtum algebra of $\hat{L}_+$, $\hat{L}_-$ and $\hat{L}_0$ operators. The
successful results achieved in predicting the discrete spectra of both systems
have put in evidence the reliability and accuracy of the theory.
| [
{
"version": "v1",
"created": "Thu, 13 Jun 1996 18:45:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Espinosa--Müller",
"Ary W.",
""
],
[
"Vásquez",
"Adelio R. Matamala",
""
]
] |
quant-ph/9606014 | M. Dakna | M. Dakna, L. Knoll, and D.-G. Welsch | Direct sampling of the Susskind-Glogower phase distributions | 10 figures using a4.sty | null | 10.1103/PhysRevA.55.2360 | null | quant-ph | null | Coarse-grained phase distributions are introduced that approximate to the
Susskind--Glogower cosine and sine phase distributions. The integral relations
between the phase distributions and the phase-parametrized field-strength
distributions observable in balanced homodyning are derived and the integral
kernels are analyzed. It is shown that the phase distributions can be directly
sampled from the field-strength distributions which offers the possibility of
measuring the Susskind--Glogower cosine and sine phase distributions with
sufficiently well accuracy. Numerical simulations are performed to demonstrate
the applicability of the method.
| [
{
"version": "v1",
"created": "Fri, 14 Jun 1996 12:56:14 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Dakna",
"M.",
""
],
[
"Knoll",
"L.",
""
],
[
"Welsch",
"D. -G.",
""
]
] |
quant-ph/9606015 | R. P. Singh | G.S. Agarwal and R.P. Singh | Complementarity and Phase Distributions for Angular Momentum Systems | 9 pages, 3 figures available on request, replaced with minor typos
corrected in abstract, to appear in Physics Letters A | null | 10.1016/0375-9601(96)00357-X | PRL-LASQO-96 | quant-ph | null | Interferences in the distributions of complementary variables for angular
momentum - two level systems are discussed. A quantum phase distribution is
introduced for angular momentum. Explicit results for the phase distributions
and the number distributions for atomic coherent states, squeezed states and
superpositions of coherent states are given. These results clearly demonstrate
the issue of complementarity and provide us with results analogous to those for
the radiation field.
| [
{
"version": "v1",
"created": "Sat, 15 Jun 1996 06:56:38 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Jun 1996 17:26:14 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Agarwal",
"G. S.",
""
],
[
"Singh",
"R. P.",
""
]
] |
quant-ph/9606016 | Shomeek Mukhopadhyay | C.S.Unnikrishnan and Shomeek Mukhopadhyay (Tata Institute of
Fundamental Research,Bombay) | Sonoluminescence as Quantum Vaccum Radiation | 2 pages,Revtex,No figures,Submitted to PRL(comments) | null | 10.1103/PhysRevLett.77.4690 | null | quant-ph | null | We argue that the available experimental data is not compatible with models
of sonoluminescence which invoke dynamical properties of the interface without
regard to the compositional properties of the trapped gas inside the bubble.
| [
{
"version": "v1",
"created": "Sun, 16 Jun 1996 22:18:34 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Unnikrishnan",
"C. S.",
"",
"Tata Institute of\n Fundamental Research,Bombay"
],
[
"Mukhopadhyay",
"Shomeek",
"",
"Tata Institute of\n Fundamental Research,Bombay"
]
] |
quant-ph/9606017 | Arthur Jabs | Arthur Jabs | Quantum Mechanics in Terms of Realism | Latex, 88 pages, 6 figures. The present version is a thorough
revision, taking experimental and theoretical progress into account | null | null | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | .We expound an alternative to the Copenhagen interpretation of the formalism
of nonrelativistic quantum mechanics. The basic difference is that the new
interpretation is formulated in the language of epistemological realism. The
{\psi} function is no longer interpreted as a probability amplitude of the
observed behaviour of elementary particles but as an objective physical field
representing the particles themselves. The particles are thus extended objects
whose extension varies in time according to the variation of {\psi}. They are
considered as fundamental regions of space with some kind of nonlocality. There
is no wave-particle duality. The point-particle-like behaviour is explained by
spatial contraction in a deterministic reduction process.
| [
{
"version": "v1",
"created": "Mon, 17 Jun 1996 00:42:59 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Feb 2015 08:22:30 GMT"
},
{
"version": "v3",
"created": "Sun, 12 Jun 2016 07:05:38 GMT"
},
{
"version": "v4",
"created": "Wed, 5 Jul 2017 09:58:24 GMT"
},
{
"version": "v5",
"created": "Wed, 17 Jul 2019 16:30:05 GMT"
}
] | 2019-07-18T00:00:00 | [
[
"Jabs",
"Arthur",
""
]
] |
quant-ph/9606018 | Vipul Periwal | Bruno Nachtergaele and Vipul Periwal | Quantum logic as a sum over classical logic gates | Plain TeX, 3 figures, 15 pages incl. figures | null | null | PUPT-1628 | quant-ph | null | It is shown that certain natural quantum logic gates, {\it i.e.} unitary time
evolution matrices for spin-\frac{1}{2} quantum spins, can be represented as
sums, with appropriate phases, over classical logic gates, in a direct analogy
with the Feynman path integral representation of quantum mechanics. On the
other hand, it is shown that a natural quantum gate obtained by analytically
continuing the transfer matrix of the anisotropic nearest-neighbour Ising model
to imaginary time, does not admit such a representation.
| [
{
"version": "v1",
"created": "Sun, 16 Jun 1996 21:58:55 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Nachtergaele",
"Bruno",
""
],
[
"Periwal",
"Vipul",
""
]
] |
quant-ph/9606019 | Jose Acacio de Barros | Patrick Suppes (Stanford University, USA), J. Acacio de Barros
(Federal University at Juiz de Fora, Brazil), and Adonai S. Sant'Anna
(Federal University at Parana, Brazil) | A Proposed Experiment Showing that Classical Fields Can Violate Bell's
Inequalities | LaTeX, 10 pages, one figure (in LaTeX) | null | null | null | quant-ph atom-ph | null | We show one can use classical fields to modify a quantum optics experiment so
that Bell's inequalities will be violated. This happens with continuous random
variables that are local, but we need to use the correlation matrix to prove
there can be no joint probability distribution of the observables.
| [
{
"version": "v1",
"created": "Wed, 19 Jun 1996 00:35:48 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Suppes",
"Patrick",
"",
"Stanford University, USA"
],
[
"de Barros",
"J. Acacio",
"",
"Federal University at Juiz de Fora, Brazil"
],
[
"Sant'Anna",
"Adonai S.",
"",
"Federal University at Parana, Brazil"
]
] |
quant-ph/9606020 | Jose Acacio de Barros | Patrick Suppes (Stanford University, USA), J. Acacio de Barros
(Federal University at Juiz de Fora, Brazil), and Adonai S. Sant'Anna
(Federal University at Parana, Brazil) | Violation of Bell's Inequalities with a Local Theory of Photons | LaTeX, 11 pages, one figure (in LaTeX), submitted to Foundations of
Physics Letters | null | 10.1007/BF02190030 | null | quant-ph atom-ph | null | We use a local theory of photons purely as particles to model the
single-photon experiment proposed by Tan, Walls, and Collett. Like Tan et al.
we are able to derive a violation of Bell's inequalities for photon counts
coincidence measurements. Our local probabilistic theory does not use any
specific quantum mechanical calculations.
| [
{
"version": "v1",
"created": "Wed, 19 Jun 1996 04:01:40 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Suppes",
"Patrick",
"",
"Stanford University, USA"
],
[
"de Barros",
"J. Acacio",
"",
"Federal University at Juiz de Fora, Brazil"
],
[
"Sant'Anna",
"Adonai S.",
"",
"Federal University at Parana, Brazil"
]
] |
quant-ph/9606021 | Ali Mostafazadeh | Ali Mostafazadeh | Quantum Adiabatic Approximation, Quantum Action, and Berry's Phase | uuencoded LaTeX file, 5 pages | Phys.Lett. A232 (1997) 395-398 | 10.1016/S0375-9601(97)00391-5 | Uni. of Alberta Preprint June 1996 | quant-ph | null | An alternative interpretation of the quantum adiabatic approximation is
presented. This interpretation is based on the ideas originally advocated by
David Bohm in his quest for establishing a hidden variable alternative to
quantum mechanics. It indicates that the validity of the quantum adiabatic
approximation is a sufficient condition for the separability of the quantum
action function in the time variable. The implications of this interpretation
for Berry's adiabatic phase and its semi-classical limit are also discussed.
| [
{
"version": "v1",
"created": "Wed, 19 Jun 1996 23:03:35 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Mostafazadeh",
"Ali",
""
]
] |
quant-ph/9606022 | Ali Mostafazadeh | Ali Mostafazadeh | Comment on Cyclic quantum-evolution dependence on the Hamiltonian and
geometric phase | LaTeX file, 2 pages | Phys.Rev. A55 (1997) 4640-4641 | 10.1103/PhysRevA.55.4640 | Uni. of Alberta Preprint April 1996 | quant-ph | null | It is shown that the analysis and the main result of the article by L-A. Wu
[Phys. Rev. A 53, 2053 (1996)] are completely erroneous.
| [
{
"version": "v1",
"created": "Thu, 20 Jun 1996 01:07:02 GMT"
}
] | 2009-10-30T00:00:00 | [
[
"Mostafazadeh",
"Ali",
""
]
] |
quant-ph/9606023 | Brif Constantin | A. Vourdas (University of Liverpool), C. Brif and A. Mann (Technion,
Haifa) | Factorisation of analytic representations in the unit disk and
number-phase statistics of a quantum harmonic oscillator | to appear in J. Phys. A, LaTeX, 13 pages, no figures. More
information on http://www.technion.ac.il/~brif/science.html | J.Phys.A29:5887-5898,1996 | 10.1088/0305-4470/29/18/018 | null | quant-ph | null | The inner-outer part factorisation of analytic representations in the unit
disk is used for an effective characterisation of the number-phase statistical
properties of a quantum harmonic oscillator. It is shown that the factorisation
is intimately connected to the number-phase Weyl semigroup and its properties.
In the Barut-Girardello analytic representation the factorisation is
implemented as a convolution. Several examples are given which demonstrate the
physical significance of the factorisation and its role for quantum statistics.
In particular, we study the effect of phase-space interference on the
factorisation properties of a superposition state.
| [
{
"version": "v1",
"created": "Sat, 22 Jun 1996 10:10:59 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Vourdas",
"A.",
"",
"University of Liverpool"
],
[
"Brif",
"C.",
"",
"Technion,\n Haifa"
],
[
"Mann",
"A.",
"",
"Technion,\n Haifa"
]
] |
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