id
stringlengths 9
16
| submitter
stringlengths 1
64
⌀ | authors
stringlengths 3
62.8k
| title
stringlengths 1
382
| comments
stringlengths 1
1.15k
⌀ | journal-ref
stringlengths 1
557
⌀ | doi
stringlengths 7
153
⌀ | report-no
stringlengths 1
509
⌀ | categories
stringlengths 5
125
| license
stringclasses 9
values | abstract
stringlengths 6
6.09k
| versions
listlengths 1
187
| update_date
timestamp[s]date 2007-05-23 00:00:00
2025-04-04 00:00:00
| authors_parsed
sequencelengths 1
2.83k
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
quant-ph/9806042 | Masanori Ohya | Masanori Ohya | Fundamentals of quantum mutual entropy and capacity | 13 pages, Latex | OpenSyst.Info.Dyn.6:69-78,1999 | null | null | quant-ph | null | The study of mutual entropy (information) and capacity in classica l system
was extensively done after Shannon by several authors like Kolmogor ov and
Gelfand. In quantum systems, there have been several definitions of t he mutual
entropy for classical input and quantum output. In 1983, the autho r defined
the fully quantum mechanical mutual entropy by means of the relati ve entropy
of Umegaki, and he extended it to general quantum systems by the relative
entropy of Araki and Uhlmann. When the author introduced the quantu m mutual
entropy, he did not indicate that it contains other definitions of the mutual
entropy including classical one, so that there exist several misu nderstandings
for the use of the mutual entropy (information) to compute the capacity of
quantum channels. Therefore in this note we point out that our quantum mutual
entropy generalizes others and where the m isuse occurs.
| [
{
"version": "v1",
"created": "Fri, 12 Jun 1998 07:39:29 GMT"
},
{
"version": "v2",
"created": "Sun, 14 Jun 1998 11:41:46 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ohya",
"Masanori",
""
]
] |
quant-ph/9806043 | Wolfgang Tittel | W. Tittel, J. Brendel, H. Zbinden, and N. Gisin | Violation of Bell inequalities by photons more than 10 km apart | 4 pages, REVTeX, 2 postscript figures included | Phys.Rev.Lett. 81 (1998) 3563-3566 | 10.1103/PhysRevLett.81.3563 | null | quant-ph | null | A Franson-type test of Bell inequalities by photons 10.9 km apart is
presented. Energy-time entangled photon-pairs are measured using two-channel
analyzers, leading to a violation of the inequalities by 16 standard deviations
without subtracting accidental coincidences. Subtracting them, a 2-photon
interference visibility of 95.5% is observed, demonstrating that distances up
to 10 km have no significant effect on entanglement. This sets quantum
cryptography with photon pairs as a practical competitor to the schemes based
on weak pulses.
| [
{
"version": "v1",
"created": "Fri, 12 Jun 1998 13:36:51 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Tittel",
"W.",
""
],
[
"Brendel",
"J.",
""
],
[
"Zbinden",
"H.",
""
],
[
"Gisin",
"N.",
""
]
] |
quant-ph/9806044 | L. F. Santos | L. F. Santos and C. O. Escobar | Stochastic Motion of an Open Bosonic String | Submitted to Phys. Rev. D, 9 pages RevTex, reference removed, no
pictures | Phys.Lett. A256 (1999) 89-94 | 10.1016/S0375-9601(99)00231-5 | null | quant-ph hep-th | null | We show that the classical stochastic motion of an open bosonic string leads
to the same results as the standard first quantization of this system. For
this, the diffusion constant governing the process has to be proportional to
\alpha ', the Regge slope parameter, which is the only constant, along with the
velocity of light, needed to describe the motion of a string.
| [
{
"version": "v1",
"created": "Fri, 12 Jun 1998 21:59:01 GMT"
},
{
"version": "v2",
"created": "Sun, 28 Jun 1998 22:54:17 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Santos",
"L. F.",
""
],
[
"Escobar",
"C. O.",
""
]
] |
quant-ph/9806045 | Peter David Drummond | P.D. Drummond and M. Hillery | Quantum theory of dispersive electromagnetic modes | null | null | 10.1103/PhysRevA.59.691 | null | quant-ph | null | A quantum theory of dispersion for an inhomogeneous solid is obtained, from a
starting point of multipolar coupled atoms interacting with an electromagnetic
field. The dispersion relations obtained are equivalent to the standard
classical Sellmeir equations obtained from the Drude-Lorentz model. In the
homogeneous (plane-wave) case, we obtain the detailed quantum mode structure of
the coupled polariton fields, and show that the mode expansion in all branches
of the dispersion relation is completely defined by the refractive index and
the group-velocity for the polaritons. We demonstrate a straightforward
procedure for exactly diagonalizing the Hamiltonian in one, two or
three-dimensional environments, even in the presence of longitudinal
phonon-exciton dispersion, and an arbitrary number of resonant transitions with
different frequencies. This is essential, since it is necessary to include at
least one phonon (I.R.) and one exciton (U.V.) mode, in order to accurately
represent dispersion in transparent solid media. Our method of diagonalization
does not require an explicit solution of the dispersion relation, but relies
instead on the analytic properties of Cauchy contour integrals over all
possible mode frequencies. When there is longitudinal phonon dispersion, the
relevant group-velocity term is modified so that it only includes the purely
electromagnetic part of the group velocity.
| [
{
"version": "v1",
"created": "Fri, 12 Jun 1998 23:17:43 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Drummond",
"P. D.",
""
],
[
"Hillery",
"M.",
""
]
] |
quant-ph/9806046 | Bozhidar Zakhariev Iliev | Bozhidar Z. Iliev (Institute for Nuclear Research and Nuclear Energy,
Bulgarian Academy of Sciences, Sofia, Bulgaria) | Fibre bundle formulation of nonrelativistic quantum mechanics. III.
Pictures and integrals of motion | 19 standard (11pt, A4) LaTeX 2e pages. The packages AMS-LaTeX and
amsfonts are required. New references and comments are added. Minor style
chages. Continuation of quant-ph/9803083, quant-ph/9803084 and
quant-ph/9804062. For continuation of the series view
http://www.inrne.bas.bg/mathmod/bozhome/ | J.Phys.A34:4935-4950,2001 | 10.1088/0305-4470/34/23/310 | null | quant-ph gr-qc hep-th | null | We propose a new systematic fibre bundle formulation of nonrelativistic
quantum mechanics. The new form of the theory is equivalent to the usual one
but it is in harmony with the modern trends in theoretical physics and
potentially admits new generalizations in different directions. In it a pure
state of some quantum system is described by a state section (along paths) of a
(Hilbert) fibre bundle. It's evolution is determined through the bundle
(analogue of the) Schr\"odinger equation. Now the dynamical variables and the
density operator are described via bundle morphisms (along paths). The
mentioned quantities are connected by a number of relations derived in this
work.
In this third part of our series we investigate the bundle analogues of the
conventional pictures of motion. In particular, there are found the state
sections and bundle morphisms corresponding to state vectors and observables
respectively. The equations of motion for these quantities are derived too.
Using the results obtained, we consider from the bundle view-point problems
concerning the integrals of motion. An invariant (bundle) necessary and
sufficient conditions for a dynamical variable to be an integral of motion are
found.
| [
{
"version": "v1",
"created": "Sat, 13 Jun 1998 09:38:28 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Oct 1998 13:33:57 GMT"
},
{
"version": "v3",
"created": "Fri, 30 Oct 1998 15:08:28 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Iliev",
"Bozhidar Z.",
"",
"Institute for Nuclear Research and Nuclear Energy,\n Bulgarian Academy of Sciences, Sofia, Bulgaria"
]
] |
quant-ph/9806047 | Chris Adami | C. Adami and N.J. Cerf | What information theory can tell us about quantum reality | LaTeX with llncs.cls, 11 pages, 6 postscript figures, Proc. of 1st
NASA Workshop on Quantum Computation and Quantum Communication (QCQC 98) | null | null | KRL MAP-204 | quant-ph | null | An investigation of Einstein's ``physical'' reality and the concept of
quantum reality in terms of information theory suggests a solution to quantum
paradoxes such as the Einstein-Podolsky-Rosen (EPR) and the Schroedinger-cat
paradoxes. Quantum reality, the picture based on unitarily evolving
wavefunctions, is complete, but appears incomplete from the observer's point of
view for fundamental reasons arising from the quantum information theory of
measurement. Physical reality, the picture based on classically accessible
observables is, in the worst case of EPR experiments, unrelated to the quantum
reality it purports to reflect. Thus, quantum information theory implies that
only correlations, not the correlata, are physically accessible: the mantra of
the Ithaca interpretation of quantum mechanics.
| [
{
"version": "v1",
"created": "Sun, 14 Jun 1998 00:06:16 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Adami",
"C.",
""
],
[
"Cerf",
"N. J.",
""
]
] |
quant-ph/9806048 | Chris Adami | C. Adami and N.J. Cerf (Caltech) | Quantum computation with linear optics | LaTeX with llncs.cls, 11 pages with 5 postscript figures, Proc. of
1st NASA Workshop on Quantum Computation and Quantum Communication (QCQC 98) | null | null | KRL MAP-222 | quant-ph | null | We present a constructive method to translate small quantum circuits into
their optical analogues, using linear components of present-day quantum optics
technology only. These optical circuits perform precisely the computation that
the quantum circuits are designed for, and can thus be used to test the
performance of quantum algorithms. The method relies on the representation of
several quantum bits by a single photon, and on the implementation of universal
quantum gates using simple optical components (beam splitters, phase shifters,
etc.). The optical implementation of Brassard et al.'s teleportation circuit, a
non-trivial 3-bit quantum computation, is presented as an illustration.
| [
{
"version": "v1",
"created": "Sun, 14 Jun 1998 00:38:37 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Adami",
"C.",
"",
"Caltech"
],
[
"Cerf",
"N. J.",
"",
"Caltech"
]
] |
quant-ph/9806049 | Arvind | Arvind(Guru Nanak Dev University, Amritsar, India) and N.
Mukunda(IISc, Bangalore, India) | Bell's inequalities, multiphoton states and phase space distributions | 16-pages in revtex with three ps figure included using epsf | Phys.Lett. A259 (1999) 421-426 | 10.1016/S0375-9601(99)00471-5 | null | quant-ph | null | The connection between quantum optical nonclassicality and the violation of
Bell's inequalities is explored. Bell type inequalities for the electromagnetic
field are formulated for general states of quantised radiation and their
violation is connected to other nonclassical properties of the field. This is
achieved by considering states with an arbitrary number of photons and
carefully identifying the hermitian operators whose expectation values do not
admit any local hidden variable description. We relate the violation of these
multi-photon inequalities to properties of phase space distribution functions
such as the diagonal coherent state distribution function and the Wigner
function. Finally, the family of 4-mode states with Gaussian Wigner
distributions is analysed, bringing out in this case the connection of
violation of Bell type inequalities with the nonclassical property of
squeezing.
| [
{
"version": "v1",
"created": "Sun, 14 Jun 1998 14:39:24 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Arvind",
"",
"",
"Guru Nanak Dev University, Amritsar, India"
],
[
"Mukunda",
"N.",
"",
"IISc, Bangalore, India"
]
] |
quant-ph/9806050 | Shmuel Gurvitz | S.A. Gurvitz | Density-matrix approach to coherent transport and the measurement
problem | 6 pages, references updated | null | null | null | quant-ph cond-mat | null | Bloch-type equations for description of coherent transport in mesoscopic
systems are applied for a study of the continuous measurement process. Both the
detector and the measured system are described quantum mechanically. It is
shown that the Schr\"odinger evolution of the entire system cannot be
accommodated with the measurement collapse. The latter leads to quantum jumps
which can be experimentally detected.
| [
{
"version": "v1",
"created": "Mon, 15 Jun 1998 13:02:13 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Aug 1998 09:28:18 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Gurvitz",
"S. A.",
""
]
] |
quant-ph/9806051 | Carsten Henkel | Carsten Henkel, Hartmut Wallis, Nathalie Westbrook, Chris I.
Westbrook, Alain Aspect, Klaus Sengstock, and Wolfgang Ertmer | Theory of atomic diffraction from evanescent waves | to be published in Applied Phys. B (accepted 17 june 1999). Slightly
modified version with updated bibliography (14 pages, 8 figures). Uses
Springer journal style files svjour.cls, svglobal.clo, and graphicx.sty | Appl. Phys. B 69 (1999) 277-289 | 10.1007/s003400050808 | null | quant-ph | null | We review recent theoretical models and experiments dealing with the
diffraction of neutral atoms from a reflection grating, formed by a standing
evanescent wave. We analyze diffraction mechanisms proposed for normal and
grazing incidence, point out their scopes and confront the theory with
experiment.
| [
{
"version": "v1",
"created": "Mon, 15 Jun 1998 16:23:36 GMT"
},
{
"version": "v2",
"created": "Tue, 20 Jul 1999 13:52:18 GMT"
}
] | 2021-08-06T00:00:00 | [
[
"Henkel",
"Carsten",
""
],
[
"Wallis",
"Hartmut",
""
],
[
"Westbrook",
"Nathalie",
""
],
[
"Westbrook",
"Chris I.",
""
],
[
"Aspect",
"Alain",
""
],
[
"Sengstock",
"Klaus",
""
],
[
"Ertmer",
"Wolfgang",
""
]
] |
quant-ph/9806052 | Norman Dombey | A Calogeracos and N Dombey | Klein Tunnelling and the Klein Paradox | 17 pages | Int.J.Mod.Phys. A14 (1999) 631-644 | 10.1142/S0217751X99000312 | SUSX-TH-97-019 | quant-ph | null | The Klein paradox is reassessed by considering the properties of a finite
square well or barrier in the Dirac equation. It is shown that spontaneous
positron emission occurs for a well if the potential is strong enough. The
vacuum charge and lifetime of the well are estimated. If the well is wide
enough, a seemingly constant current is emitted. These phenomena are transient
whereas the tunnelling first calculated by Klein is time-independent. Klein
tunnelling is a property of relativistic wave equations, not necessarily
connected to particle emission. The Coulomb potential is investigated in this
context: it is shown that a heavy nucleus of sufficiently large $Z$ will bind
positrons. Correspondingly, it is expected that as $Z$ increases the Coulomb
barrier will become increasingly transparent to positrons. This is an example
of Klein tunnelling.
| [
{
"version": "v1",
"created": "Mon, 15 Jun 1998 15:56:08 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Calogeracos",
"A",
""
],
[
"Dombey",
"N",
""
]
] |
quant-ph/9806053 | Christian Wiele | Christian Wiele, Fritz Haake, Kazimierz Rzazewski | Superradiant Laser: First-Order Phase Transition and Non-stationary
Regime | RevTeX, 10 pages, 4 figures | null | 10.1007/s100530050272 | null | quant-ph | null | We solve the superradiant laser model in two limiting cases. First the
stationary low-pumping regime is considered where a first-order phase
transition in the semiclassical solution occurs. This discontinuity is smeared
out in the quantum regime. Second, we solve the model in the non-stationary
regime where we find a temporally periodic solution. For a certain parameter
range well separated pulses may occur.
| [
{
"version": "v1",
"created": "Tue, 16 Jun 1998 09:13:58 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Wiele",
"Christian",
""
],
[
"Haake",
"Fritz",
""
],
[
"Rzazewski",
"Kazimierz",
""
]
] |
quant-ph/9806054 | S. Popescu | Noah Linden and Sandu Popescu | The Halting Problem for Quantum Computers | 4 pages, Revised version | null | null | null | quant-ph | null | We argue that the halting problem for quantum computers which was first
raised by Myers, is by no means solved, as has been claimed recently. We
explicitly demonstrate the difficulties that arise in a quantum computer when
different branches of the computation halt at different, unknown, times.
| [
{
"version": "v1",
"created": "Tue, 16 Jun 1998 12:14:16 GMT"
},
{
"version": "v2",
"created": "Mon, 29 Jun 1998 16:53:20 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Linden",
"Noah",
""
],
[
"Popescu",
"Sandu",
""
]
] |
quant-ph/9806055 | Murray Peshkin | Murray Peshkin (Argonne National Laboratory) | Force-Free Interactions and Nondispersive Phase Shifts in Interferometry | 9 pages, 1 figure. Submitted to Foundations of Physics for the Daniel
Greenberger festschrift | Found.Phys. 29 (1999) 481-489 | null | PHY-8962-TH-98 | quant-ph | null | Zeilinger's observation that phenomena of the Aharonov-Bohm type lead to
nondispersive, i.e. energy-independent, phase shifts in interferometers is
generalized in a new proof which shows that the precise condition for
nondispersivity is a force-free interaction. The converse theorem is disproved
by a conceptual counter example. Applications to several nondispersive
interference phenomena are reviewed briefly. Those fall into two classes which
are objectively distinct from each other in that in the first class phase
shifts depend only on the topology of the interfering beam paths while in the
second class force-free physical interactions take place at identifiable points
along the path. Apparent disagreements in the literature about the topological
nature of the phenomena in the second class stem from differing definitions.
| [
{
"version": "v1",
"created": "Tue, 16 Jun 1998 18:33:43 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Peshkin",
"Murray",
"",
"Argonne National Laboratory"
]
] |
quant-ph/9806056 | Salman Habib | Alex J. Dragt and Salman Habib | How Wigner Functions Transform Under Symplectic Maps | 8 pages, 6 figures [RevTeX/epsfig, macro included]. To appear in
Proceedings of the Advanced Beam Dynamics Workshop on Quantum Aspects of Beam
Physics (Monterey, CA 1998) | null | null | LA-UR-98-2347 | quant-ph | null | It is shown that, while Wigner and Liouville functions transform in an
identical way under linear symplectic maps, in general they do not transform
identically for nonlinear symplectic maps. Instead there are ``quantum
corrections'' whose hbar tending to zero limit may be very complicated.
Examples of the behavior of Wigner functions in this limit are given in order
to examine to what extent the corresponding Liouville densities are recovered.
| [
{
"version": "v1",
"created": "Tue, 16 Jun 1998 23:30:30 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Dragt",
"Alex J.",
""
],
[
"Habib",
"Salman",
""
]
] |
quant-ph/9806057 | Mark Burgess | Mark Burgess | Effective field theory of resonant 2-level atoms | null | null | null | null | quant-ph | null | The phenomenological two-level atom is re-analysed using the methods of
effective field theory. By presenting the Dicke-Jaynes-Cummings model in real
space, an exact diagonalization is accomplished going beyond the rotating wave
approximation. The meaning of the symmetries and conserved quantities in the
theory is discussed and the model is related to non-equilibrium field theory.
The structure of the solution raises a question about the rotating wave
approximation in quantum mechanics.
| [
{
"version": "v1",
"created": "Wed, 17 Jun 1998 09:19:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Burgess",
"Mark",
""
]
] |
quant-ph/9806058 | Pawel Horodecki | Pawel Horodecki, Michal Horodecki and Ryszard Horodecki | Bound entanglement can be activated | RevTeX, 4 pages | Phys.Rev.Lett. 82 (1999) 1056-1059 | 10.1103/PhysRevLett.82.1056 | null | quant-ph | null | Bound entanglement is the noisy entanglement which cannot be distilled to a
singlet form. Thus it cannot be used alone for quantum communication purposes.
Here we show that, nevertheless, the bound entanglement can be, in a sense,
pumped into single pair of free entangled particles. It allows for
teleportation via the pair with the fidelity impossible to achieve without
support of bound entanglement. The result also suggests that the distillable
entanglement may be not additive.
| [
{
"version": "v1",
"created": "Wed, 17 Jun 1998 20:15:46 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Horodecki",
"Pawel",
""
],
[
"Horodecki",
"Michal",
""
],
[
"Horodecki",
"Ryszard",
""
]
] |
quant-ph/9806059 | Ulvi Yurtsever | Ulvi Yurtsever | Quantum Mechanics and Algorithmic Randomness | plain LaTeX, 11 pages | null | null | MSTR-9801 | quant-ph | null | A long sequence of tosses of a classical coin produces an apparently random
bit string, but classical randomness is an illusion: the algorithmic
information content of a classically-generated bit string lies almost entirely
in the description of initial conditions. This letter presents a simple
argument that, by contrast, a sequence of bits produced by tossing a quantum
coin is, almost certainly, genuinely (algorithmically) random. This result can
be interpreted as a strengthening of Bell's no-hidden-variables theorem, and
relies on causality and quantum entanglement in a manner similar to Bell's
original argument.
| [
{
"version": "v1",
"created": "Thu, 18 Jun 1998 00:02:18 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Dec 2000 21:43:25 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Yurtsever",
"Ulvi",
""
]
] |
quant-ph/9806060 | Slobodan Prvanovic | S. Prvanovic and Z. Maric (Institute of Physics, Belgrade, Serbia) | Operator Formulation of Classical Mechanics and the Problem of
Measurement | 7 pages \tightenlines, RevTeX, typos corrected, one reference added,
minor changes of wording | null | null | null | quant-ph | null | The basic concepts of classical mechanics are given in the operator form. The
dynamical equation for a hybrid system, consisting of quantum and classical
subsystems, is introduced and analyzed in the case of an ideal nonselective
measurement. The nondeterministic evolution is found to be the consequence of
the superposition of two different deterministic evolutions.
| [
{
"version": "v1",
"created": "Thu, 18 Jun 1998 12:03:45 GMT"
},
{
"version": "v2",
"created": "Tue, 23 Jun 1998 13:57:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Prvanovic",
"S.",
"",
"Institute of Physics, Belgrade, Serbia"
],
[
"Maric",
"Z.",
"",
"Institute of Physics, Belgrade, Serbia"
]
] |
quant-ph/9806061 | S. V. M. Satyanarayana | S. Sivakumar | Photon-added coherent states as nonlinear coherent states | Rev Tex file with two figures as postscript files attached. Email:
[email protected] | null | 10.1088/0305-4470/32/18/317 | null | quant-ph | null | The states $|\alpha,m>$, defined as ${a^{\dagger}}^{m}|\alpha>$ up to a
normalization constant and $m$ is a nonnegative integer, are shown to be the
eigenstates of $f(\hat{n},m)\hat{a}$ where $f(\hat{n},m)$ is a nonlinear
function of the number operator $\hat{n}$. The explicit form of $f(\hat{n},m)$
is constructed. The eigenstates of this operator for negative values of $m$ are
introduced. The properties of these states are discussed and compared with
those of the state $|\alpha,m >$.
| [
{
"version": "v1",
"created": "Thu, 18 Jun 1998 12:21:36 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Jun 1998 08:44:32 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Sivakumar",
"S.",
""
]
] |
quant-ph/9806062 | Astrid Lambrecht | A. Lambrecht, M.T. Jaekel and S. Reynaud | Generating photon pulses with an oscillating cavity | 6 pages, 3 figures, LaTeX, needs EuroPhysics Letters Stylefile, to
appear in Europhysics Letters | Europhys.Lett. 43 (1998) 147-152 | 10.1209/epl/i1998-00333-0 | null | quant-ph | null | We study the generation of photon pulses from thermal field fluctuations
through opto-mechanical coupling to a cavity with an oscillatory motion. Pulses
are regularly spaced and become sharp for a high finesse cavity.
| [
{
"version": "v1",
"created": "Thu, 18 Jun 1998 12:26:49 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Lambrecht",
"A.",
""
],
[
"Jaekel",
"M. T.",
""
],
[
"Reynaud",
"S.",
""
]
] |
quant-ph/9806063 | Vladimir Buzek | M. Hillery, V. Buzek, and A. Berthiaume | Quantum secret sharing | 6 pages, revtex, revised version, to appear in Phys. Rev. A | null | 10.1103/PhysRevA.59.1829 | null | quant-ph | null | Secret sharing is a procedure for splitting a message into several parts so
that no subset of parts is sufficient to read the message, but the entire set
is. We show how this procedure can be implemented using GHZ states. In the
quantum case the presence of an eavesdropper will introduce errors so that his
presence can be detected. We also show how GHZ states can be used to split
quantum information into two parts so that both parts are necessary to
reconstruct the original qubit.
| [
{
"version": "v1",
"created": "Thu, 18 Jun 1998 13:14:54 GMT"
},
{
"version": "v2",
"created": "Tue, 1 Dec 1998 15:06:45 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Hillery",
"M.",
""
],
[
"Buzek",
"V.",
""
],
[
"Berthiaume",
"A.",
""
]
] |
quant-ph/9806064 | Fernando Kokubun | L.D. Almeida, F. Kokubun, D. Hadjimichef | Bound-State Problem in a One-Dimensional Cantor-like Potential | 2 pages, 1 PS figure, LaTeX2e, to appear in the Proc. of VI Hadrons
Physics, Florianopolis, Brazil, 1998, World Scientific | null | null | null | quant-ph | null | One of the best systems for the study of quantum chaos is the atomic nucleus.
A confined particle with general boundary conditions can present chaos and the
eigenvalue problem can exhibit this fact. We study a toy model in which the
potential has a Cantor-like form. The eigenvalue spectrum presents a Devil's
staircase ordering in the semi-classical limit.
| [
{
"version": "v1",
"created": "Thu, 18 Jun 1998 22:52:00 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Almeida",
"L. D.",
""
],
[
"Kokubun",
"F.",
""
],
[
"Hadjimichef",
"D.",
""
]
] |
quant-ph/9806065 | Visitors | Howard Barnum (Hampshire College and ISIS) | Quantum Rate-Distortion Coding | LaTeX, 6 pages, preliminary version | null | null | HC-QI-001 | quant-ph | null | I introduce rate-distortion theory for quantum coding, and derive a lower
bound, involving the coherent information, on the rate at which qubits must be
used to encode a quantum source with a given maximum level of distortion per
source emission. The convexity of the "information rate-distortion function"
which defines this bound is also derived.
| [
{
"version": "v1",
"created": "Fri, 19 Jun 1998 14:01:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Barnum",
"Howard",
"",
"Hampshire College and ISIS"
]
] |
quant-ph/9806066 | W. A. Hofer | W. A. Hofer (TU - Wien) | Internal structures of electrons and photons: the concept of extended
particles revisited | 14 pages (RevTeX one column) and 1 figure (eps). For a full list of
available papers see http://info.tuwien.ac.at/cms/wh/ | Physica A256:178-196,1998 | 10.1016/S0378-4371(98)00092-2 | MW-03/98 | quant-ph | null | The theoretical foundations of quantum mechanics and de Broglie--Bohm
mechanics are analyzed and it is shown that both theories employ a formal
approach to microphysics. By using a realistic approach it can be established
that the internal structures of extended particles comply with a wave-equation.
Including external potentials yields the Schrodinger equation, which, in this
context, is arbitrary due to internal energy components. The statistical
interpretation of wave functions in quantum theory as well as Heisenberg's
uncertainty relations are shown to be an expression of this, fundamental,
arbitrariness. Electrons and photons can be described by an identical
formalism, providing formulations equivalent to the Maxwell equations.
Electrostatic interactions justify the initial assumption of electron-wave
stability: the stability of electron waves can be referred to vanishing
intrinsic fields of interaction. The theory finally points out some fundamental
difficulties for a fully covariant formulation of quantum electrodynamics,
which seem to be related to the existing infinity problems in this field.
| [
{
"version": "v1",
"created": "Sat, 20 Jun 1998 12:35:36 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Hofer",
"W. A.",
"",
"TU - Wien"
]
] |
quant-ph/9806067 | Tamas Fulop | T. Fulop, S. D. Katz | Building a frame and gauge free formulation of quantum mechanics | Changes: Several small improvements in the text, altered title. 35
pages, LaTeX | null | null | KEK Preprint 98-86 | quant-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The wave function of quantum mechanics is not a boost invariant and gauge
invariant quantity. Correspondingly, reference frame dependence and gauge
dependence are inherited to most of the elements of the usual formulation of
quantum mechanics (including operators, states and events). If a frame
dependent and gauge dependent formalism is called, in short, a relative
formalism, then the aim of the paper is to establish an absolute, i.e., frame
and gauge free, reformulation of quantum mechanics. To fulfil this aim, we
develop absolute quantities and the corresponding equations instead of the wave
function and the Schr\"odinger equation. The absolute quantities have a more
direct physical interpretation than the wave function has, and the
corresponding equations express explicitly the independent physical aspects of
the system which are contained in the Schr\"odinger equation in a mixed and
more hidden form. Based on the absolute quantities and equations, events,
states and physical quantities are introduced also in an absolute way. The
formalism makes it possible to obtain some sharper versions of the uncertainty
relation and to extend the validity of Ehrenfest's theorem. The absolute
formulation allows wide extensions of quantum mechanics. To give examples, we
discuss two known nonlinear extensions and, in close detail, a dissipative
system. An argument is provided that the absolute formalism may lead to an
explanation of the Aharonov-Bohm effect purely in terms of the electromagnetic
field strength tensor. At last, on special relativistic and curved spacetimes,
absolute quantities and equations instead of the Klein-Gordon wave function and
equation are given, and their nonrelativistic limit is derived.
| [
{
"version": "v1",
"created": "Sun, 21 Jun 1998 06:00:31 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Sep 1998 09:01:26 GMT"
},
{
"version": "v3",
"created": "Mon, 16 Jan 2012 16:13:34 GMT"
}
] | 2012-01-17T00:00:00 | [
[
"Fulop",
"T.",
""
],
[
"Katz",
"S. D.",
""
]
] |
quant-ph/9806068 | Konrad Banaszek | Konrad Banaszek and Krzysztof Wodkiewicz (Uniwersytet Warszawski) | Quantum Nonlocality in Phase Space | 4 pages, REVTeX | Phys. Rev. Lett. 82, 2009 (1999) | 10.1103/PhysRevLett.82.2009 | null | quant-ph | null | We propose an experiment demonstrating the nonlocality of a quantum
singlet-like state generated from a single photon incident on a beam splitter.
Each of the two spatially separated apparatuses in the setup performs a
strongly unbalanced homodyning, employing a single photon counting detector. We
show that the correlation functions violating the Bell inequalities in the
proposed experiment are given by the joint two-mode Q-function and the Wigner
function of the optical singlet-like state. This establishes a direct
relationship between two intriguing aspects of quantum mechanics: the
nonlocality of entangled states and the noncommutativity of quantum
observables, which underlies the nonclassical structure of phase space
quasidistribution functions.
| [
{
"version": "v1",
"created": "Sun, 21 Jun 1998 12:28:39 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Banaszek",
"Konrad",
"",
"Uniwersytet Warszawski"
],
[
"Wodkiewicz",
"Krzysztof",
"",
"Uniwersytet Warszawski"
]
] |
quant-ph/9806069 | Konrad Banaszek | Konrad Banaszek and Krzysztof Wodkiewicz (Uniwersytet Warszawski) | Nonlocality of Einstein-Podolsky-Rosen State in Wigner Representation | 3 pages, REVTeX | Phys. Rev. A 58, 4345 (1998) | 10.1103/PhysRevA.58.4345 | null | quant-ph | null | We demonstrate that the Wigner function of the Einstein-Podolsky-Rosen state,
though positive definite, provides a direct evidence of the nonlocal character
of this state. The proof is based on an observation that the Wigner function
describes correlations in the joint measurement of the phase space displaced
parity operator.
| [
{
"version": "v1",
"created": "Sun, 21 Jun 1998 12:30:22 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Banaszek",
"Konrad",
"",
"Uniwersytet Warszawski"
],
[
"Wodkiewicz",
"Krzysztof",
"",
"Uniwersytet Warszawski"
]
] |
quant-ph/9806070 | Henry Stapp | Henry P. Stapp (Lawrence Berkeley Laboratory) | Comment on ``Possibility of quantum mechanics being nonlocal'' | Reply submitted to PRA on June 20, 1998 to Unruh's paper about my
1997 article in the Amer. J. Phys | null | null | LBNL-41813 | quant-ph | null | A recent proof, formulated in the symbolic language of modal logic, shows
that a well-defined formulation of the possibility mentioned in the title is
answered affirmatively. In the paper being commented upon several proposals
were made about how to translate this symbolic proof into prose, and it was
concluded, on the basis of those proposed translations, that either the proof
was invalid or that an unwarranted reality assumption was made. However, those
interpretations deviate in small but important ways from the precise logical
path followed in the proof. It is explained here how by staying on this path
one avoids the difficulties that those deviations engendered.
| [
{
"version": "v1",
"created": "Sun, 21 Jun 1998 18:10:00 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Stapp",
"Henry P.",
"",
"Lawrence Berkeley Laboratory"
]
] |
quant-ph/9806071 | Wang Zhen | Zhen Wang (LiaoNing Normal University, P. R. China) | The Time's Arrow within the Uncertainty Quantum | LaTex, 23 pages, no figure | null | null | LNU-98-06 | quant-ph | null | A generalized framework is developed which uses a set description instead of
wavefunction to emphasize the role of the observer. Such a framework is found
to be very effective in the study of the measurement problem and time's arrow.
Measurement in classical and quantum theory is given a unified treatment. With
the introduction of the concept of uncertainty quantum which is the basic unit
of measurement, we show that the time's arrow within the uncertainty quantum is
just opposite to the time's arrow in the observable reality. A special constant
is discussed which explains our sensation of time and provides a permanent
substrate for all change. It is shown that the whole spacetime connects
together in a delicate structure.
| [
{
"version": "v1",
"created": "Mon, 22 Jun 1998 14:14:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Wang",
"Zhen",
"",
"LiaoNing Normal University, P. R. China"
]
] |
quant-ph/9806072 | C. W. J. Beenakker | C.W.J. Beenakker (Leiden University) | Thermal radiation and amplified spontaneous emission from a random
medium | 4 pages, including 2 figures | Phys. Rev. Lett. 81, 1829 (1998) | 10.1103/PhysRevLett.81.1829 | null | quant-ph cond-mat.mes-hall | null | We compute the statistics of thermal emission from systems in which the
radiation is scattered chaotically, by relating the photocount distribution to
the scattering matrix - whose statistical properties are known from
random-matrix theory. We find that the super-Poissonian noise is that of a
black body with a reduced number of degrees of freedom. The general theory is
applied to a disordered slab and to a chaotic cavity, and is extended to
include amplifying as well as absorbing systems. We predict an excess noise of
amplified spontaneous emission in a random laser below the laser threshold.
| [
{
"version": "v1",
"created": "Mon, 22 Jun 1998 16:03:33 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Beenakker",
"C. W. J.",
"",
"Leiden University"
]
] |
quant-ph/9806073 | Qiong-gui Lin | Qiong-gui Lin | Levinson theorem in two dimensions | LaTeX, no figure | Phys.Rev. A56 (1997) 1938-1944 | 10.1103/PhysRevA.56.1938 | null | quant-ph | null | A two-dimensional analogue of Levinson's theorem for nonrelativistic quantum
mechanics is established, which relates the phase shift at threshold(zero
momentum) for the $m$th partial wave to the total number of bound states with
angular momentum $m\hbar(m=0,1,2,...)$ in an attractive central field.
| [
{
"version": "v1",
"created": "Tue, 23 Jun 1998 03:29:14 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Lin",
"Qiong-gui",
""
]
] |
quant-ph/9806074 | Laszlo E. Szabo | Laszlo E. Szabo (Eotvos University, Budapest) | On an attempt to resolve the EPR-Bell paradox via Reichenbachian concept
of common cause | Revised (Changes in the Title and the Abstract. A Postscript is
added, which makes serious modification in the conclusions.)17 pages,
ps-file, 4 figures included, an illustrative computer program for PC:
http://hps.elte.hu/~leszabo/EPRind.html | International Journal of Theoretical Physics 39 (2000) 901--911 | 10.1023/A:1003691216444 | Eotvos-HPS 98-6 | quant-ph gr-qc hep-th math-ph math.MP physics.hist-ph physics.pop-ph | null | Reichenbach's Common Cause Principle claims that if there is correlation
between two events and none of them is directly causally influenced by the
other, then there must exist a third event that can, as a common cause, account
for the correlation. The EPR-Bell paradox consists in the problem that we
observe correlations between spatially separated events in the EPR-experiments,
which do not admit common-cause-type explanation; and it must therefore be
inevitably concluded, that, contrary to relativity theory, in the realm of
quantum physics there exists action at a distance, or at least superluminal
causal propagation is possible; that is, either relativity theory or
Reichenbach's common cause principle fails. By means of closer analyses of the
concept of common cause and a more precise reformulation of the EPR
experimental scenario, I will sharpen the conclusion we can draw from the
violation of Bell's inequalities. It will be explicitly shown that the
correla-tions we encounter in the EPR experiment could have common causes; that
is, Reichen-bach's Common Cause Principle does not fail in quantum mechanics.
Moreover, these common causes satisfy the locality conditions usually required.
In the Revised Version of the paper I added a Postscript from which it turns
out that the solution such obtained is, contrary to the original title,
incomplete. It turns out that a new problem arises: some combinations of the
common cause events do statistically cor-relate with the measurement
operations.
| [
{
"version": "v1",
"created": "Tue, 23 Jun 1998 17:12:53 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Jun 1998 15:27:42 GMT"
},
{
"version": "v3",
"created": "Mon, 6 Mar 2000 01:02:37 GMT"
}
] | 2012-07-10T00:00:00 | [
[
"Szabo",
"Laszlo E.",
"",
"Eotvos University, Budapest"
]
] |
quant-ph/9806075 | Qiong-gui Lin | Qiong-gui Lin | Levinson theorem for Dirac particles in two dimensions | LaTeX, no figure | Phys.Rev. A57 (1998) 3478-3488 | 10.1103/PhysRevA.57.3478 | null | quant-ph | null | The Levinson theorem for nonrelativistic quantum mechanics in two spatial
dimensions is generalized to Dirac particles moving in a central field. The
theorem relates the total number of bound states with angular momentum $j$
($j=\pm 1/2, \pm 3/2, ... $), $n_j$, to the phase shifts $\eta_j(\pm E_k)$ of
scattering states at zero momentum as follows: $\eta_j(\mu)+\eta_j(-\mu)=
n_j\pi$.
| [
{
"version": "v1",
"created": "Tue, 23 Jun 1998 04:02:54 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Lin",
"Qiong-gui",
""
]
] |
quant-ph/9806076 | Baowen Li | Jie Liu, Bambi Hu and Baowen Li (Department of Physics and Centre for
Nonlinear Studies, Hong Kong Baptist University, Hong Kong, China) | Nonadiabatic geometric phase for the cyclic evolution of a
time-dependent Hamiltonian system | 16 Revtex pages, no figure. Submitted to PRA | null | 10.1103/PhysRevA.58.3448 | HKBU-CNS-9807 | quant-ph chao-dyn cond-mat nlin.CD | null | The geometric phases of the cyclic states of a generalized harmonic
oscillator with nonadiabatic time-periodic parameters are discussed in the
framework of squeezed state. It is shown that the cyclic and quasicyclic
squeezed states correspond to the periodic and quasiperiodic solutions of an
effective Hamiltonian defined on an extended phase space, respectively. The
geometric phase of the cyclic squeezed state is found to be a phase-space area
swept out by a periodic orbit. Furthermore, a class of cyclic states are
expressed as a superposition of an infinte number of squeezed states. Their
geometric phases are found to be independent of $\hbar$, and equal to
$-(n+1/2)$ times the classical nonadiabatic Hannay angle.
| [
{
"version": "v1",
"created": "Tue, 23 Jun 1998 07:33:54 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Liu",
"Jie",
"",
"Department of Physics and Centre for\n Nonlinear Studies, Hong Kong Baptist University, Hong Kong, China"
],
[
"Hu",
"Bambi",
"",
"Department of Physics and Centre for\n Nonlinear Studies, Hong Kong Baptist University, Hong Kong, China"
],
[
"Li",
"Baowen",
"",
"Department of Physics and Centre for\n Nonlinear Studies, Hong Kong Baptist University, Hong Kong, China"
]
] |
quant-ph/9806077 | Stefan Scheel | L. Knoell, S. Scheel, E. Schmidt, D.-G. Welsch | Quantum state transformation by dispersive and absorbing four-port
devices | 24 pages, RevTeX | Phys. Rev. A 59, 4716 (1999) | 10.1103/PhysRevA.59.4716 | FSUJ TPI QO-8/98 | quant-ph | null | The recently derived input-output relations for the radiation field at a
dispersive and absorbing four-port device [T. Gruner and D.-G. Welsch, Phys.
Rev. A 54, 1661 (1996)] are used to derive the unitary transformation that
relates the output quantum state to the input quantum state, including
radiation and matter and without placing frequency restrictions. It is shown
that for each frequency the transformation can be regarded as a well-behaved
SU(4) group transformation that can be decomposed into a product of U(2) and
SU(2) group transformations. Each of them may be thought of as being realized
by a particular lossless four-port device. If for narrow-bandwidth radiation
far from the medium resonances the absorption matrix of the four-port device
can be disregarded, the well-known SU(2) group transformation for a lossless
device is recognized. Explicit formulas for the transformation of Fock-states
and coherent states are given.
| [
{
"version": "v1",
"created": "Tue, 23 Jun 1998 15:17:06 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Knoell",
"L.",
""
],
[
"Scheel",
"S.",
""
],
[
"Schmidt",
"E.",
""
],
[
"Welsch",
"D. -G.",
""
]
] |
quant-ph/9806078 | Nicolas Cerf | N. J. Cerf (Caltech), L. K. Grover (Bell labs), C. P. Williams (JPL) | Nested quantum search and NP-complete problems | 18 pages RevTeX, 3 Postscript figures | Phys.Rev. A61 (2000) 032303 | 10.1103/PhysRevA.61.032303 | KRL MAP-225 | quant-ph | null | A quantum algorithm is known that solves an unstructured search problem in a
number of iterations of order $\sqrt{d}$, where $d$ is the dimension of the
search space, whereas any classical algorithm necessarily scales as $O(d)$. It
is shown here that an improved quantum search algorithm can be devised that
exploits the structure of a tree search problem by nesting this standard search
algorithm. The number of iterations required to find the solution of an average
instance of a constraint satisfaction problem scales as $\sqrt{d^\alpha}$, with
a constant $\alpha<1$ depending on the nesting depth and the problem
considered. When applying a single nesting level to a problem with constraints
of size 2 such as the graph coloring problem, this constant $\alpha$ is
estimated to be around 0.62 for average instances of maximum difficulty. This
corresponds to a square-root speedup over a classical nested search algorithm,
of which our presented algorithm is the quantum counterpart.
| [
{
"version": "v1",
"created": "Tue, 23 Jun 1998 23:52:57 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cerf",
"N. J.",
"",
"Caltech"
],
[
"Grover",
"L. K.",
"",
"Bell labs"
],
[
"Williams",
"C. P.",
"",
"JPL"
]
] |
quant-ph/9806079 | Dr. A. K. Pati | Arun Kumar Pati and Suresh V. Lawande (Theory Division, BARC, Mumbai,
India) | Quantum Zeno Dynamics and Inhibition of Geometric Phase | Latex file, no figure, 4 Pages in twocolumn style, submitted to
Physical Review Letter | null | null | null | quant-ph | null | If unitary evolution of a quantum system is interrupted by a sequence of
measurements we call the dynamics as quantum Zeno dynamics. We show that under
quantum Zeno dynamics not only the transition probability (leading to quantum
Zeno effect) but also phases are affected. We call this new effect as quantum
Zeno phase effect (QZPE) which says that under repeated measurements the
geometric phase of a quantum system can be inhibited. Since geometric phase
attributes a memory to a quatum system this result also proves that under
quantum Zeno dynamics the memory of a system can be erased. We have proposed a
neutron interference experiment where this prediction can be tested. We also
beleive that with Itano's kind of set up for two-level systems this prediction
can be tested. This will provide a new way of controlling phase shift in
interference experiment by doing repeated measurements.
| [
{
"version": "v1",
"created": "Wed, 24 Jun 1998 07:03:53 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Pati",
"Arun Kumar",
"",
"Theory Division, BARC, Mumbai,\n India"
],
[
"Lawande",
"Suresh V.",
"",
"Theory Division, BARC, Mumbai,\n India"
]
] |
quant-ph/9806080 | Georg Junker | F.Cannata, G. Junker and J. Trost | Solvable potentials, non-linear algebras, and associated coherent states | 10 pages, 1 figure, uses AIP macros (included) | AIPConf.Proc.453:209-218,1998 | 10.1063/1.57097 | null | quant-ph | null | Using the Darboux method and its relation with supersymmetric quantum
mechanics we construct all SUSY partners of the harmonic oscillator. With the
help of the SUSY transformation we introduce ladder operators for these partner
Hamiltonians and shown that they close a quadratic algebra. The associated
coherent states are constructed and discussed in some detail.
| [
{
"version": "v1",
"created": "Wed, 24 Jun 1998 08:20:17 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cannata",
"F.",
""
],
[
"Junker",
"G.",
""
],
[
"Trost",
"J.",
""
]
] |
quant-ph/9806081 | Michael L. Gorodetsky | Vladimir B.Braginsky, Michael L.Gorodetsky, Farid Ya.Khalili | Quantum limits and symphotonic states in free-mass gravitational-wave
antennae | 21 pages, 2 figures | Phys.Lett. A246 (1998) 485-497 | 10.1016/S0375-9601(98)00537-4 | null | quant-ph | null | Quantum mechanics sets severe limits on the sensitivity and required
circulating energy in traditional free-mass gravitational-wave antennas. One
possible way to avoid these restrictions is the use of intracavity QND
measurements. We analyze a new QND observable, which possesses a number of
features that make it a promising candidate for such measurements and propose a
practical scheme for the realization of this measurement. In combination with
an advanced coordinate meter, this scheme makes it possible to lower
substantially the requirements on the circulating power.
| [
{
"version": "v1",
"created": "Wed, 24 Jun 1998 16:00:23 GMT"
},
{
"version": "v2",
"created": "Mon, 21 Sep 1998 13:18:43 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Braginsky",
"Vladimir B.",
""
],
[
"Gorodetsky",
"Michael L.",
""
],
[
"Khalili",
"Farid Ya.",
""
]
] |
quant-ph/9806082 | Mio Murao | M. Murao, D. Jonathan, M. B. Plenio and V. Vedral | Quantum telecloning and multiparticle entanglement | 7 pages, 2 figures | Phys.Rev.A59:156-161,1999 | 10.1103/PhysRevA.59.156 | null | quant-ph | null | A quantum telecloning process combining quantum teleportation and optimal
quantum cloning from one input to M outputs is presented. The scheme relies on
the establishment of particular multiparticle entangled states, which function
as multiuser quantum information channels. The entanglement structure of these
states is analyzed and shown to be crucial for this type of information
processing.
| [
{
"version": "v1",
"created": "Wed, 24 Jun 1998 17:08:52 GMT"
}
] | 2011-08-11T00:00:00 | [
[
"Murao",
"M.",
""
],
[
"Jonathan",
"D.",
""
],
[
"Plenio",
"M. B.",
""
],
[
"Vedral",
"V.",
""
]
] |
quant-ph/9806083 | Bruno Galvan | Bruno Galvan | Could quantum statistical regularities derive from a measure on the
boundary conditions of a classical universe? | 32 pages, LaTex | null | null | null | quant-ph | null | The problem of defining the boundary conditions for the universe is
considered here in the framework of a classical dynamical theory, pointing out
that a measure on boundary conditions must be included in the theory in order
to explain the statistical regularities of evolution. It is then suggested that
quantum statistical regularities also could derive from this measure. An
explicit definition of such a measure is proposed, using both a simplified
model of the universe based on classical mechanics and the non-relativistic
quantum mechanics formalism. The peculiarity of such a measure is that it does
not apply to the initial conditions of the universe, i.e. to the initial
positions and momenta of particles, but to their initial and final positions,
from which the path is derived by means of the least action principle. This
formulation of the problem is crucial and it is supported by the observation
that it is incorrect to liken the determination of the boundary conditions of
the universe to the preparation of a laboratory system, in which the initial
conditions of the system are obviously determined. Some possible objections to
this theory are then discussed. Specifically, the EPR paradox is discussed, and
it is explained by showing that, in general, a measure on the boundary
conditions of the universe generates preinteractive correlations, and that in
the presence of such correlations Bell's inequality can no longer be proven
true. Finally, it is shown that if one broadens the dynamical scheme of the
theory to encompass phenomena such as particle decay and annihilation, the
least action principle allows for an indeterministic evolution of the system.
| [
{
"version": "v1",
"created": "Wed, 24 Jun 1998 19:33:17 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Galvan",
"Bruno",
""
]
] |
quant-ph/9806084 | Christof Zalka | Christof Zalka (T-6 LANL) | Fast versions of Shor's quantum factoring algorithm | 37 pages, LaTeX, 1 figure | null | null | null | quant-ph | null | We present fast and highly parallelized versions of Shor's algorithm. With a
sizable quantum computer it would then be possible to factor numbers with
millions of digits. The main algorithm presented here uses FFT-based fast
integer multiplication. The quick reader can just read the introduction and the
``Results'' section.
| [
{
"version": "v1",
"created": "Wed, 24 Jun 1998 23:51:37 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zalka",
"Christof",
"",
"T-6 LANL"
]
] |
quant-ph/9806085 | Arvind | Arvind(Guru Nanak Dev University, Amritsar, India) and N.
Mukunda(IISc, Bangalore, India) | General radiation states and Bell's inequalities | 4-pages in revtex with one ps figure included | null | null | null | quant-ph | null | The connection between quantum optical nonclassicality and the violation of
Bell's inequalities is explored. Bell type inequalities for the electromagnetic
field are formulated for general states(arbitrary number or photons, pure or
mixed) of quantised radiation and their violation is connected to other
nonclassical properties of the field. Classical states are shown to obey these
inequalities and for the family of centered Gaussian states the direct
connection between violation of Bell-type inequalities and squeezing is
established.
| [
{
"version": "v1",
"created": "Thu, 25 Jun 1998 11:49:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Arvind",
"",
"",
"Guru Nanak Dev University, Amritsar, India"
],
[
"Mukunda",
"N.",
"",
"IISc, Bangalore, India"
]
] |
quant-ph/9806086 | Castagnoli Giuseppe | Giuseppe Castagnoli (Information Technology Dept., Elsag Bailey,
Genova, Italy), Dalida Monti (Universita` di Genova and Elsag Bailey, Genova,
Italy) | Exploiting Particle Statistics in Quantum Computation | 7 pages, no figures. This manuscript is a further development of
"Quantum Computation Based on Particle Statistics", quant-ph/9806010 3 Jun
1998. Submitted to Fourth Biannual IQSA Meeting QUANTUM STRUCTURES '98 | null | null | Elsag Bailey C.I. no. 047, 1998 | quant-ph | null | We describe a plausible-speculative form of quantum computation which
exploits particle (fermionic, bosonic) statistics, under a generalized,
counterfactual interpretation thereof. In the idealized situation of an
isolated system, it seems that this form of computation yields to
NP-complete=P.
| [
{
"version": "v1",
"created": "Thu, 25 Jun 1998 15:54:49 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Castagnoli",
"Giuseppe",
"",
"Information Technology Dept., Elsag Bailey,\n Genova, Italy"
],
[
"Monti",
"Dalida",
"",
"Universita` di Genova and Elsag Bailey, Genova,\n Italy"
]
] |
quant-ph/9806087 | Ruvin Ferber | Ruvin Ferber (University of Latvia, Riga, Latvia) | Fundamentals of Relativity Providing Time, Distance and Velocity
Standards | 7 pages | null | null | null | quant-ph | null | The paper presents an attempt to suggest an alternative way of considering
the fundamentals of Einstein's special relativity theory. Its formulation based
on introducing an inertial reference system by rigid linking of clocks to a
free entity to define proper time is self-contradictory since the operation of
rigid linking involves interaction which is excluded by definition for a free
entity. The way to overcome this inconsistency is proposed by postulating that
each free entity (object, particle) has to be ideal clocks by itself, providing
ideal internal time standards defined by the only intrinsic feature of a free
entity, namely its proper mass which means that de Broglie's periodic
phenomenon has to be considered as a fundamental principle needed to built the
special relativity, along with the principle of indistinguishability allowing
to define the particle's proper mass with ideal accuracy. Further, the internal
distance standard is provided by passing to Compton wavelength and the velocity
standard is introduced by means of Hubble's law. It is proposed to interpret
the wave function as an internal system of reference undergoing distortion when
external interaction is included.
| [
{
"version": "v1",
"created": "Fri, 26 Jun 1998 15:51:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Ferber",
"Ruvin",
"",
"University of Latvia, Riga, Latvia"
]
] |
quant-ph/9806088 | Jens Eisert | J. Eisert, M. Wilkens, and M. Lewenstein | Quantum Games and Quantum Strategies | 4 pages, 4 figures, typographic sign error in the definition of the
operator J corrected | Phys. Rev. Lett. 83, 3077 (1999) | 10.1103/PhysRevLett.83.3077 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the quantization of non-zero sum games. For the particular
case of the Prisoners' Dilemma we show that this game ceases to pose a dilemma
if quantum strategies are allowed for. We also construct a particular quantum
strategy which always gives reward if played against any classical strategy.
| [
{
"version": "v1",
"created": "Fri, 26 Jun 1998 16:45:30 GMT"
},
{
"version": "v2",
"created": "Mon, 3 May 1999 18:30:45 GMT"
},
{
"version": "v3",
"created": "Wed, 29 Sep 1999 12:55:30 GMT"
},
{
"version": "v4",
"created": "Fri, 13 Mar 2020 07:11:48 GMT"
}
] | 2020-03-16T00:00:00 | [
[
"Eisert",
"J.",
""
],
[
"Wilkens",
"M.",
""
],
[
"Lewenstein",
"M.",
""
]
] |
quant-ph/9806089 | Paul Slater | Paul B. Slater (University of California) | SU(N) x S_{m}-Invariant Eigenspaces of N^{m} x N^{m} Mean Density
Matrices | 15 pages, LaTeX, single figure; we correct a small but systematic
error in our N = 3, m = 3 analysis, leading to a much simpler set of results.
Also, we have added a section (the penultimate one) entitled, "Parameterized
Families of N^{m} x N^{m} Mean Density Matrices", having observed that the
choice by Zyczkowski et al (quant-ph/9804024) of a uniform distribution over
the (N-1)-dimensional simplex spanned by the eigenvalues is somewhat
arbitrary in nature, and can be replaced by any member of a family of
(symmetric) Dirichlet distributions | null | null | null | quant-ph | null | We extend to additional probability measures and scenarios, certain of the
recent results of Krattenthaler and Slater (quant-ph/9612043), whose original
motivation was to obtain quantum analogs of seminal work on universal data
compression of Clarke and Barron. KS obtained explicit formulas for the
eigenvalues and eigenvectors of the 2^m x 2^m density matrices derived by
averaging the m-fold tensor products with themselves of the 2 x 2 density
matrices. The weighting was done with respect to a one-parameter (u) family of
probability distributions, all the members of which are spherically-symmetric
(SU(2)-invariant) over the ``Bloch sphere'' of two-level quantum systems. For u
= 1/2, one obtains the normalized volume element of the minimal monotone
(Bures) metric. In this paper, analyses parallel to those of KS are conducted,
based on an alternative "natural" measure on the density matrices recently
proposed by Zyczkowski, Horodecki, Sanpera, and Lewenstein (quant-ph/9804024).
The approaches of KS and that based on ZHSL are found to yield [1 + m/2]
identical SU(2) x S_{m}-invariant eigenspaces (but not coincident eigenvalues
for m > 3). Companion results, based on the SU(3) form of the ZHSL measure, are
obtained for the twofold and threefold tensor products of the 3 x 3 density
matrices. We find a rather remarkable limiting procedure (selection rule) for
recovering from these analyses, the (permutationally-symmetrized) multiplets of
SU(3) constructed from two or three particles. We also analyze the scenarios
(all for m = 2) N = 2 x 3, N= 2 x 3 x 2, N= 3 x 2 x 2 and N = 4 and, in
addition, generalize the ZHSL measure, so that it incorporates a family of
(symmetric) Dirichlet distributions (rather than simply the uniform
distribution), defined on the (N-1)-dimensional simplex of eigenvalues.
| [
{
"version": "v1",
"created": "Fri, 26 Jun 1998 21:49:18 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Aug 1998 20:06:19 GMT"
},
{
"version": "v3",
"created": "Fri, 21 Aug 1998 21:46:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Slater",
"Paul B.",
"",
"University of California"
]
] |
quant-ph/9806090 | Wim van Dam | Wim van Dam (U of Oxford, CWI) | Two Classical Queries versus One Quantum Query | 6 pages, LaTeX2e, no figures, minor changes and corrections | null | null | CQC-2CQ:1QQ | quant-ph cs.CC | null | In this note we study the power of so called query-limited computers. We
compare the strength of a classical computer that is allowed to ask two
questions to an NP-oracle with the strength of a quantum computer that is
allowed only one such query. It is shown that any decision problem that
requires two parallel (non-adaptive) SAT-queries on a classical computer can
also be solved exactly by a quantum computer using only one SAT-oracle call,
where both computations have polynomial time-complexity. Such a simulation is
generally believed to be impossible for a one-query classical computer. The
reduction also does not hold if we replace the SAT-oracle by a general
black-box. This result gives therefore an example of how a quantum computer is
probably more powerful than a classical computer. It also highlights the
potential differences between quantum complexity results for general oracles
when compared to results for more structured tasks like the SAT-problem.
| [
{
"version": "v1",
"created": "Sat, 27 Jun 1998 02:53:13 GMT"
},
{
"version": "v2",
"created": "Wed, 26 Aug 1998 01:06:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"van Dam",
"Wim",
"",
"U of Oxford, CWI"
]
] |
quant-ph/9806091 | Joerg Steinbach | J. Steinbach and C.C. Gerry | An efficient scheme for the deterministic maximal entanglement of N
trapped ions | 4 pages, no figures, submitted to PRL, under review, Revised Version:
Incorporated referee comments | Phys.Rev.Lett.81:5528-5531,1998 | 10.1103/PhysRevLett.81.5528 | null | quant-ph | null | We propose a method for generating maximally entangled states of N two-level
trapped ions. The method is deterministic and independent of the number of ions
in the trap. It involves a controlled-NOT acting simultaneously on all the ions
through a dispersive interaction. We explore the potential application of our
scheme for high precision frequency standards.
| [
{
"version": "v1",
"created": "Sat, 27 Jun 1998 19:19:46 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Nov 1998 16:47:58 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Steinbach",
"J.",
""
],
[
"Gerry",
"C. C.",
""
]
] |
quant-ph/9806092 | David Vitali | David Vitali and Paolo Grigolini | Chaos, Thermodynamics and Quantum Mechanics: an Application to Celestial
Dynamics | 9 pages, two tables included, RevTex. Concluding part of Sec. IV
revised and shortened | Phys.Lett.A249:248-258,1998 | 10.1016/S0375-9601(98)00745-2 | null | quant-ph chao-dyn nlin.CD | null | We address the issue of the quantum-classical correspondence in chaotic
systems using, as recently done by Zurek [e-print quant-ph/9802054], the solar
system as a whole as a case study: this author shows that the classicality of
the planetary motion is ensured by the environment-induced decoherence. We show
that equivalent results are provided by the theories of spontaneous
fluctuations and that these latter theories, in some cases, result in a still
faster process of decoherence. We show that, as an additional benefit, the
assumption of spontaneous fluctuation makes it possible to genuinely derive
thermodynamics from mechanics, namely, without implicitly assuming
thermodynamics.
| [
{
"version": "v1",
"created": "Mon, 29 Jun 1998 09:53:10 GMT"
},
{
"version": "v2",
"created": "Mon, 7 Sep 1998 08:36:47 GMT"
}
] | 2011-08-04T00:00:00 | [
[
"Vitali",
"David",
""
],
[
"Grigolini",
"Paolo",
""
]
] |
quant-ph/9806093 | Vladimir Buzek | Vladimir Buzek | Reconstruction of Liouvillian Superoperators | 4 pages, revtex, 1 eps figure, accepted for publication in Phys. Rev.
A | null | 10.1103/PhysRevA.58.1723 | null | quant-ph | null | We show how to determine (reconstruct) a master equation governing the time
evolution of an open quantum system.
We present a general algorithm for the reconstruction of the corresponding
Liouvillian superoperators. Dynamics of a two-level atom in various
environments is discussed in detail.
| [
{
"version": "v1",
"created": "Mon, 29 Jun 1998 14:29:58 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Buzek",
"Vladimir",
""
]
] |
quant-ph/9806094 | Guifre Vidal Bonafont | Guifre Vidal and Rolf Tarrach | Robustness of entanglement | 27 pages, LaTex, 3 figures | Phys.Rev. A59 (1999) 141-155 | 10.1103/PhysRevA.59.141 | ECM-UB-33-98 | quant-ph | null | In the quest of completely describing entanglement in the general case of a
finite number of parties sharing a physical system of finite dimensional
Hilbert space a new entanglement magnitude is introduced for its pure and mixed
states: robustness. It corresponds to the minimal amount of mixing with locally
prepared states which washes out all entanglement. It quantifies in a sense the
endurence of entanglement against noise and jamming. Its properties are studied
comprehensively. Analytical expressions for the robustness are given for pure
states of binary systems, and analytical bounds for mixed states of binary
systems. Specific results are obtained mainly for the qubit-qubit system. As
byproducts local pseudomixtures are generalized, a lower bound for the relative
volume of separable states is deduced and arguments for considering convexity a
necessary condition of any entanglement magnitude are put forward.
| [
{
"version": "v1",
"created": "Mon, 29 Jun 1998 17:15:35 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Vidal",
"Guifre",
""
],
[
"Tarrach",
"Rolf",
""
]
] |
quant-ph/9806095 | Barbara M. Terhal | B.M. Terhal, I.L. Chuang, D.P. DiVincenzo, M. Grassl, J.A. Smolin | Simulating quantum operations with mixed environments | 4 pages Revtex + 1 fig, pictures at
http://stout.physics.ucla.edu/~smolin/tetrahedron .Several small corrections | Phys.Rev.A60:881,1999 | 10.1103/PhysRevA.60.881 | null | quant-ph | null | We study the physical resources required to implement general quantum
operations, and provide new bounds on the minimum possible size which an
environment must be in order to perform certain quantum operations. We prove
that contrary to a previous conjecture, not all quantum operations on a
single-qubit can be implemented with a single-qubit environment, even if that
environment is initially prepared in a mixed state. We show that a mixed
single-qutrit environment is sufficient to implement a special class of
operations, the generalized depolarizing channels.
| [
{
"version": "v1",
"created": "Mon, 29 Jun 1998 19:35:22 GMT"
},
{
"version": "v2",
"created": "Thu, 12 Nov 1998 19:47:25 GMT"
}
] | 2011-07-19T00:00:00 | [
[
"Terhal",
"B. M.",
""
],
[
"Chuang",
"I. L.",
""
],
[
"DiVincenzo",
"D. P.",
""
],
[
"Grassl",
"M.",
""
],
[
"Smolin",
"J. A.",
""
]
] |
quant-ph/9806096 | Sang Pyo Kim | Jung Kon Kim and Sang Pyo Kim | One-Parameter Squeezed Gaussian States of Time-Dependent Harmonic
Oscillator and Selection Rule for Vacuum States | 13 Pages, ReVTeX, no figures | J.Phys.A32:2711-2718,1999 | 10.1088/0305-4470/32/14/012 | null | quant-ph | null | By using the invariant method we find one-parameter squeezed Gaussian states
for both time-independent and time-dependent oscillators. The squeezing
parameter is expressed in terms of energy expectation value for
time-independent case and represents the degree of mixing positive and negative
frequency solutions for time-dependent case. A {\it minimum uncertainty
proposal} is advanced to select uniquely vacuum states at each moment of time.
We show that the Gaussian states with minimum uncertainty coincide with the
true vacuum state for time-independent oscillator and the Bunch-Davies vacuum
for a massive scalar field in a de Sitter spacetime.
| [
{
"version": "v1",
"created": "Tue, 30 Jun 1998 05:40:55 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Nov 1998 08:40:09 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kim",
"Jung Kon",
""
],
[
"Kim",
"Sang Pyo",
""
]
] |
quant-ph/9806097 | Marc-Thierry Jaekel | Marc-Thierry Jaekel (Laboratoire de Physique The'orique de l'Ecole
Normale Supe'rieure) and Serge Reynaud (Laboratoire Kastler Brossel) | Quantum Localisation Observables and Accelerated Frames | 14 pages | Eur.Phys.J. D5 (1999) 9 | 10.1007/s100530050223 | LPTENS 97/62 | quant-ph gr-qc | null | We define quantum observables associated with Einstein localisation in
space-time. These observables are built on Poincare' and dilatation generators.
Their commutators are given by spin observables defined from the same symmetry
generators. Their shifts under transformations to uniformly accelerated frames
are evaluated through algebraic computations in conformal algebra. Spin number
is found to vary under such transformations with a variation involving further
observables introduced as irreducible quadrupole momenta. Quadrupole
observables may be dealt with as non commutative polarisations which allow one
to define step operators increasing or decreasing the spin number by unity.
| [
{
"version": "v1",
"created": "Tue, 30 Jun 1998 08:37:04 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Jaekel",
"Marc-Thierry",
"",
"Laboratoire de Physique The'orique de l'Ecole\n Normale Supe'rieure"
],
[
"Reynaud",
"Serge",
"",
"Laboratoire Kastler Brossel"
]
] |
quant-ph/9806098 | Antonio Vidiella-Barranco | A. Vidiella-Barranco and J.A. Roversi (Universidade Estadual de
Campinas, SP, Brazil) | Quantum state engineering via unitary transformations | 5 pages in RevTeX, no figures, accepted for publication in Phys. Rev.
A | Phys. Rev. A, vol 58, 3349 (1998) | 10.1103/PhysRevA.58.3349 | A 041-98 | quant-ph physics.optics | null | We construct a Hamiltonian for the generation of arbitrary pure states of the
quantized electromagnetic field. The proposition is based upon the fact that a
unitary transformation for the generation of number states has been already
found. The general unitary transformation here obtained, would allow the use of
nonlinear interactions for the production of pure states. We discuss the
applicability of this method by giving examples of generation of simple
superposition states. We also compare our Hamiltonian with the one resulting
from the interaction of trapped ions with two laser fields.
| [
{
"version": "v1",
"created": "Tue, 30 Jun 1998 20:21:45 GMT"
},
{
"version": "v2",
"created": "Thu, 15 Oct 1998 14:26:50 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Vidiella-Barranco",
"A.",
"",
"Universidade Estadual de\n Campinas, SP, Brazil"
],
[
"Roversi",
"J. A.",
"",
"Universidade Estadual de\n Campinas, SP, Brazil"
]
] |
quant-ph/9807001 | null | Marcello Cini | Quantum Mechanics without Waves: a Generalization of Classical
Statistical Mechanics | 25 pages, Latex | Annals Phys. 273 (1999) 99-113 | 10.1006/aphy.1998.5892 | 1097, July 1st 1998, Dipartimento di Fisica Universita di Roma "La
Sapienza" | quant-ph cond-mat hep-th math-ph math.MP | null | We generalize classical statistical mechanics to describe the kinematics and
the dynamics of systems whose variables are constrained by a single quantum
postulate (discreteness of the spectrum of values of at least one variable of
the theory). This is possible provided we adopt Feynman's suggestion of
dropping the assumption that the probability for an event must always be a
positive number. This approach has the advantage of allowing a reformulation of
quantum theory in phase space without introducing the unphysical concept of
probability amplitudes, together with all the problems concerning their
ambiguous properties.
| [
{
"version": "v1",
"created": "Wed, 1 Jul 1998 10:08:18 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Cini",
"Marcello",
""
]
] |
quant-ph/9807002 | Ali Mostafazadeh | Ali Mostafazadeh | Time-Dependent Diffeomorphisms as Quantum Canonical Transformations and
the Time-Dependent Harmonic Oscillator | Plain Latex, J. Phys. A: Math. Gen., to appear | J.Phys.A31:6495-6503,1998 | 10.1088/0305-4470/31/30/014 | Koc University preprint April 1998 | quant-ph gr-qc hep-th | null | Quantum canonical transformations corresponding to time-dependent
diffeomorphisms of the configuration space are studied. A special class of
these transformations which correspond to time-dependent dilatations is used to
identify a previously unknown class of exactly solvable time-dependent harmonic
oscillators. The Caldirola-Kanai oscillator belongs to this class. For a
general time-dependent harmonic oscillator, it is shown that choosing the
dilatation parameter to satisfy the classical equation of motion, one obtains
the solution of the Schr\"odinger equation. A simple generalization of this
result leads to the reduction of the Schr\"odinger equation to a second order
ordinary differential equation whose special case is the auxiliary equation of
the Lewis-Riesenfeld invariant theory. Time-evolution operator is expressed in
terms of a positive real solution of this equation in a closed form, and the
time-dependent position and momentum operators are calculated.
| [
{
"version": "v1",
"created": "Wed, 1 Jul 1998 11:25:55 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mostafazadeh",
"Ali",
""
]
] |
quant-ph/9807003 | Ali Mostafazadeh | Ali Mostafazadeh | Relativistic Adiabatic Approximation and Geometric Phase | Plain LaTeX | J.Phys.A31:7829-7845,1998 | 10.1088/0305-4470/31/38/018 | Koc University preprint April 1998 | quant-ph hep-th | null | A relativistic analogue of the quantum adiabatic approximation is developed
for Klein-Gordon fields minimally coupled to electromagnetism, gravity and an
arbitrary scalar potential. The corresponding adiabatic dynamical and
geometrical phases are calculated. The method introduced in this paper avoids
the use of an inner product on the space of solutions of the Klein-Gordon
equation. Its practical advantages are demonstrated in the analysis of the
relativistic Landau level problem and the rotating cosmic string.
| [
{
"version": "v1",
"created": "Wed, 1 Jul 1998 11:40:50 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mostafazadeh",
"Ali",
""
]
] |
quant-ph/9807004 | Dr. Daniel A. Lidar | D.A. Lidar (UC Berkeley), I.L. Chuang (IBM San Jose) and K.B. Whaley
(UC Berkeley) | Decoherence Free Subspaces for Quantum Computation | 4 pages, no figures. Conditions for decoherence-free subspaces made
more explicit, updated references. To appear in PRL | Phys.Rev.Lett.81:2594,1998 | 10.1103/PhysRevLett.81.2594 | null | quant-ph math-ph math.MP | null | Decoherence in quantum computers is formulated within the Semigroup approach.
The error generators are identified with the generators of a Lie algebra. This
allows for a comprehensive description which includes as a special case the
frequently assumed spin-boson model. A generic condition is presented for
error-less quantum computation: decoherence-free subspaces are spanned by those
states which are annihilated by all the generators. It is shown that these
subspaces are stable to perturbations and moreover, that universal quantum
computation is possible within them.
| [
{
"version": "v1",
"created": "Wed, 1 Jul 1998 12:10:38 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Jul 1998 02:39:51 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Lidar",
"D. A.",
"",
"UC Berkeley"
],
[
"Chuang",
"I. L.",
"",
"IBM San Jose"
],
[
"Whaley",
"K. B.",
"",
"UC Berkeley"
]
] |
quant-ph/9807005 | Junya Shibata | Junya Shibata, Shin Takagi | A Note on (Spin-) Coherent-State Path Integral | 32 pages, 3 figures, Revtex | Int.J.Mod.Phys. B13 (1999) 107-140 | 10.1142/S0217979299000096 | null | quant-ph | null | It is pointed out that there are some fundamental difficulties with the
frequently used continuous-time formalism of the spin-coherent-state path
integral. They arise already in a single-spin system and at the level of the
"classical action" not to speak of fluctuations around the "classical path".
Similar difficulties turn out to be present in the case of the
(boson-)coherent-state path integral as well; although partially circumventable
by an ingenious trick (Klauder's $\epsilon$-prescription) at the "classical
level", they manifest themselves at the level of fluctuations. Detailed
analysis of the origin of these difficulties makes it clear that the only way
of avoiding them is to work with the proper discrete-time formalism. The thesis
is explicitly illustrated with a harmonic oscillator and a spin under a
constant magnetic field.
| [
{
"version": "v1",
"created": "Wed, 1 Jul 1998 13:54:34 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Shibata",
"Junya",
""
],
[
"Takagi",
"Shin",
""
]
] |
quant-ph/9807006 | Daniel Gottesman | Daniel Gottesman | The Heisenberg Representation of Quantum Computers | 20 pages, LaTeX. Expanded version of a plenary speech at the 1998
International Conference on Group Theoretic Methods in Physics | Group22: Proceedings of the XXII International Colloquium on Group
Theoretical Methods in Physics, eds. S. P. Corney, R. Delbourgo, and P. D.
Jarvis, pp. 32-43 (Cambridge, MA, International Press, 1999) | null | LAUR-98-2848 | quant-ph | null | Since Shor's discovery of an algorithm to factor numbers on a quantum
computer in polynomial time, quantum computation has become a subject of
immense interest. Unfortunately, one of the key features of quantum computers -
the difficulty of describing them on classical computers - also makes it
difficult to describe and understand precisely what can be done with them. A
formalism describing the evolution of operators rather than states has proven
extremely fruitful in understanding an important class of quantum operations.
States used in error correction and certain communication protocols can be
described by their stabilizer, a group of tensor products of Pauli matrices.
Even this simple group structure is sufficient to allow a rich range of quantum
effects, although it falls short of the full power of quantum computation.
| [
{
"version": "v1",
"created": "Wed, 1 Jul 1998 19:34:39 GMT"
}
] | 2009-08-21T00:00:00 | [
[
"Gottesman",
"Daniel",
""
]
] |
quant-ph/9807007 | Raymond Laflamme | W. H. Zurek | Algorithmic randomness, physical entropy, measurements, and the Demon of
Choice | 20 pages including figures in TeX | null | null | null | quant-ph | null | Measurements --- interactions which establish correlations between a system
and a recording device --- can be made thermodynamically reversible. One might
be concerned that such reversibility will make the second law of thermodynamics
vulnerable to the designs of the demon of choice, a selective version of
Maxwell's demon. The strategy of the demon of choice is to take advantage of
rare fluctuations to extract useful work, and to reversibly undo measurements
which do not lead to such a favorable but unlikely outcomes. I show that this
threat does not arise as the demon of choice cannot operate without recording
(explicitely or implicitely) whether its measurement was a success (or a
failure). Thermodynamic cost associated with such a record cannot be, on the
average, made smaller than the gain of useful work derived from the
fluctuations.
| [
{
"version": "v1",
"created": "Wed, 1 Jul 1998 20:59:01 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Zurek",
"W. H.",
""
]
] |
quant-ph/9807008 | Andreas Winter | Andreas Winter (Univ. Bielefeld) | Languages of Quantum Information Theory | 16 pages, REVTEX, typos corrected, references added and extended | null | null | null | quant-ph | null | This note will introduce some notation and definitions for information
theoretic quantities in the context of quantum systems, such as (conditional)
entropy and (conditional) mutual information. We will employ the natural
C*-algebra formalism, and it turns out that one has an allover dualism of
language: we can define everything for (compatible) observables, but also for
(compatible) C*-subalgebras. The two approaches are unified in the formalism of
quantum operations, and they are connected by a very satisfying inequality,
generalizing the well known Holevo bound. Then we turn to communication via
(discrete memoryless) quantum channels: we formulate the Fano inequality, bound
the capacity region of quantum multiway channels, and comment on the quantum
broadcast channel.
| [
{
"version": "v1",
"created": "Thu, 2 Jul 1998 12:15:54 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Jul 1998 14:56:03 GMT"
},
{
"version": "v3",
"created": "Fri, 31 Jul 1998 13:08:48 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Winter",
"Andreas",
"",
"Univ. Bielefeld"
]
] |
quant-ph/9807009 | Dr. Daniel A. Lidar | Daniel A. Lidar and Haobin Wang (UC Berkeley) | Calculating the Thermal Rate Constant with Exponential Speed-Up on a
Quantum Computer | 10 pages, no figures | Phys.Rev.E59:2429,1999 | 10.1103/PhysRevE.59.2429 | null | quant-ph physics.chem-ph | null | It is shown how to formulate the ubiquitous quantum chemistry problem of
calculating the thermal rate constant on a quantum computer. The resulting
exact algorithm scales exponentially faster with the dimensionality of the
system than all known ``classical'' algorithms for this problem.
| [
{
"version": "v1",
"created": "Thu, 2 Jul 1998 19:44:48 GMT"
}
] | 2011-07-19T00:00:00 | [
[
"Lidar",
"Daniel A.",
"",
"UC Berkeley"
],
[
"Wang",
"Haobin",
"",
"UC Berkeley"
]
] |
quant-ph/9807010 | R. F. Werner | M. Keyl, R. F. Werner (Inst. Math. Phys., TU-Braunschweig) | Optimal Cloning of Pure States, Judging Single Clones | 16 Pages, REVTeX | J.Math.Phys. 40 (1999) 3283-3299 | 10.1063/1.532887 | TUBS/IMaPh-98-14 | quant-ph | null | We consider quantum devices for turning a finite number N of d-level quantum
systems in the same unknown pure state \sigma into M>N systems of the same
kind, in an approximation of the M-fold tensor product of the state \sigma. In
a previous paper it was shown that this problem has a unique optimal solution,
when the quality of the output is judged by arbitrary measurements, involving
also the correlations between the clones. We show in this paper, that if the
quality judgement is based solely on measurements of single output clones,
there is again a unique optimal cloning device, which coincides with the one
found previously.
| [
{
"version": "v1",
"created": "Fri, 3 Jul 1998 10:09:00 GMT"
}
] | 2015-06-26T00:00:00 | [
[
"Keyl",
"M.",
"",
"Inst. Math. Phys., TU-Braunschweig"
],
[
"Werner",
"R. F.",
"",
"Inst. Math. Phys., TU-Braunschweig"
]
] |
quant-ph/9807011 | Armen B. Apyan | M. L. Ter-Mikayelyan (Institute for Physical Research, Armenia) | Entanglement Induced Radiation Processes Which are First Order in Weak
Field | 15 pages, 5 figures, text:tmstat.tex; figures:
tmfig1.ps;tmfig2.ps;tmfig3.ps;tmfig4.ps;tmfig5.ps | Opt.Commun. 158 (1998) 287-297 | 10.1016/S0030-4018(98)00493-3 | YerPhI-98-16 | quant-ph | null | Nonlinear processes of light scattering on a two-level system near resonance
are considered. The problem is reduced to the emission and absorption of an
entangled system, formed by a strong resonant field and a two-level system,
having a non-factorizing wave function.
| [
{
"version": "v1",
"created": "Fri, 3 Jul 1998 11:26:53 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Ter-Mikayelyan",
"M. L.",
"",
"Institute for Physical Research, Armenia"
]
] |
quant-ph/9807012 | David Collins | David Collins, K. W. Kim and W. C. Holton (Department of Electrical
and Computer Engineering, North Carolina State University, Raleigh) | Deutsch-Jozsa algorithm as a test of quantum computation | 10 pages, 2 figures, RevTex, Approved for publication in Phys Rev A | null | 10.1103/PhysRevA.58.R1633 | ECE-qc-98-01 | quant-ph | null | A redundancy in the existing Deutsch-Jozsa quantum algorithm is removed and a
refined algorithm, which reduces the size of the register and simplifies the
function evaluation, is proposed. The refined version allows a simpler analysis
of the use of entanglement between the qubits in the algorithm and provides
criteria for deciding when the Deutsch-Jozsa algorithm constitutes a meaningful
test of quantum computation.
| [
{
"version": "v1",
"created": "Fri, 3 Jul 1998 15:07:11 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Collins",
"David",
"",
"Department of Electrical\n and Computer Engineering, North Carolina State University, Raleigh"
],
[
"Kim",
"K. W.",
"",
"Department of Electrical\n and Computer Engineering, North Carolina State University, Raleigh"
],
[
"Holton",
"W. C.",
"",
"Department of Electrical\n and Computer Engineering, North Carolina State University, Raleigh"
]
] |
quant-ph/9807013 | Nazin S. | S.N.Molotkov (Institute of Solid State Physics, Russian Academy of
Sciences) | Experimental scheme for quantum teleportation of a single-photon packet | 7 pages, 1 figure (under request) | null | 10.1134/1.567857 | null | quant-ph | null | Both complete protocol and optical setup for experimental realization of
quantum teleportation of unknown single-photon wave packet are proposed.
| [
{
"version": "v1",
"created": "Sat, 4 Jul 1998 07:16:46 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Molotkov",
"S. N.",
"",
"Institute of Solid State Physics, Russian Academy of\n Sciences"
]
] |
quant-ph/9807014 | Reuben Shuker | D. Braunstein and R. Shuker | Absorption with inversion and amplification without inversion in a
coherently prepared V - system: a dressed state approach | 23 pages, 5 figures | null | null | bgu/lwi1 | quant-ph | null | Light induced absorption with population inversion and amplification without
population inversion (LWI) in a coherently prepared closed three level V - type
system are investigated. This study is performed from the point of view of a
two color dressed state basis. Both of these processes are possible due to
atomic coherence and quantum interference contrary to simple intuitive
predictions. Merely on physical basis, one would expect a complementary process
to the amplification without inversion. We believe that absorption in the
presence of population inversion found in the dressed state picture utilized in
this study, constitutes such a process.
Novel approximate analytic time dependent solutions, for coherences and
populations are obtained, and are compared with full numerical solutions
exhibiting excellent agreement. Steady state quantities are also calculated,
and the conditions under which the system exhibits absorption and gain with and
without inversion, in the dressed state representation are derived. It is found
that for a weak probe laser field absorption with inversion and amplification
without inversion may occur, for a range of system parameters.
| [
{
"version": "v1",
"created": "Sun, 5 Jul 1998 14:35:09 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Braunstein",
"D.",
""
],
[
"Shuker",
"R.",
""
]
] |
quant-ph/9807015 | R. E. Kastner | R. E. Kastner | Closing a Loophole in the Case Against the Counterfactual Usage of the
ABL Rule | 12 pages, Latex, 4 figures, minor wording changes | null | null | null | quant-ph | null | A currently discussed interpretation of quantum theory, Time-Symmetrized
Quantum Theory, makes certain claims about the properties of systems between
pre- and post- selection measurements. These claims are based on a
counterfactual usage of the Aharonov-Bergmann-Lebowitz (ABL) rule for
calculating the probabilities of measurement outcomes between such
measurements. It has been argued by several authors that the counterfactual
usage of the ABL rule is, in general, incorrect. This paper examines what might
appear to be a loophole in those arguments and shows that this apparent
loophole cannot be used to support a counterfactual interpretation of the ABL
rule. It is noted that the invalidity of the counterfactual usage of the ABL
rule implies that the characterization of those outcomes receiving probability
1 in a counterfactual application of the rule as `elements of reality' is, in
general, unfounded.
| [
{
"version": "v1",
"created": "Sun, 5 Jul 1998 18:00:07 GMT"
},
{
"version": "v2",
"created": "Wed, 8 Jul 1998 01:37:04 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kastner",
"R. E.",
""
]
] |
quant-ph/9807016 | Strahov Yevgeni | M. S. Marinov and Eugene Strahov (Technion, Haifa) | Spin in a variable magnetic field: the adiabatic approximation | LaTeX, 6 pges, no figures, submitted to Comptes rendus Acad.
Sci.Paris | null | 10.1016/S1287-4620(99)80063-5 | null | quant-ph | null | The problem of spin precession in a time-dependent magnetic field is
considered in the adiabatic approximation where the field direction or the
angular velocity of its rotation is changing slowly. The precession angles are
given by integrals in a way similar to the semi-classical approximation for the
Schr\"{o}dinger equation.
| [
{
"version": "v1",
"created": "Mon, 6 Jul 1998 10:19:29 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Marinov",
"M. S.",
"",
"Technion, Haifa"
],
[
"Strahov",
"Eugene",
"",
"Technion, Haifa"
]
] |
quant-ph/9807017 | Asher Peres | Asher Peres | All the Bell inequalities | Final version, 20 pages LaTeX, 4 separate pages of figures | Foundations of Physics 29 (1999) 589-614 | null | null | quant-ph | null | Bell inequalities are derived for any number of observers, any number of
alternative setups for each one of them, and any number of distinct outcomes
for each experiment. It is shown that if a physical system consists of several
distant subsystems, and if the results of tests performed on the latter are
determined by local variables with objective values, then the joint
probabilities for triggering any given set of distant detectors are convex
combinations of a finite number of Boolean arrays, whose components are either
0 or 1 according to a simple rule. This convexity property is both necessary
and sufficient for the existence of local objective variables. It leads to a
simple graphical method which produces a large number of generalized Clauser-
Horne inequalities corresponding to the faces of a convex polytope. It is
plausible that quantum systems whose density matrix has a positive partial
transposition satisfy all these inequalities, and therefore are compatible with
local objective variables, even if their quantum properties are essentially
nonlocal.
| [
{
"version": "v1",
"created": "Mon, 6 Jul 1998 10:42:39 GMT"
},
{
"version": "v2",
"created": "Tue, 31 Aug 1999 06:42:31 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Peres",
"Asher",
""
]
] |
quant-ph/9807018 | Hideo Mabuchi | H. Mabuchi and H. M. Wiseman | Retroactive quantum jumps in a strongly-coupled atom-field system | 4 pages, uses RevTex, 5 EPS figures | Phys.Rev.Lett.81:4620-4623,1998; Erratum-ibid.82:1798,1999 | 10.1103/PhysRevLett.81.4620 | null | quant-ph | null | We investigate a novel type of conditional dynamic that occurs in the
strongly-driven Jaynes-Cummings model with dissipation. Extending the work of
Alsing and Carmichael [Quantum Opt. {\bf 3}, 13 (1991)], we present a combined
numerical and analytic study of the Stochastic Master Equation that describes
the system's conditional evolution when the cavity output is continuously
observed via homodyne detection, but atomic spontaneous emission is not
monitored at all. We find that quantum jumps of the atomic state are induced by
its dynamical coupling to the optical field, in order retroactively to justify
atypical fluctuations in ocurring in the homodyne photocurrent.
| [
{
"version": "v1",
"created": "Mon, 6 Jul 1998 12:12:33 GMT"
}
] | 2009-01-23T00:00:00 | [
[
"Mabuchi",
"H.",
""
],
[
"Wiseman",
"H. M.",
""
]
] |
quant-ph/9807019 | Andreas Winter | Andreas Winter | The Capacity of the Quantum Multiple Access Channel | 7 pages, requires IEEEtran2e.cls | IEEE Trans.Info.Theor. 47 (2001) 3059-3065 | 10.1109/18.959287 | null | quant-ph | null | We define classical-quantum multiway channels for transmission of classical
information, after recent work by Allahverdyan and Saakian. Bounds on the
capacity region are derived in a uniform way, which are analogous to the
classically known ones, simply replacing Shannon entropy with von Neumann
entropy. For the single receiver case (multiple access channel) the exact
capacity region is determined. These results are applied to the case of noisy
channels, with arbitrary input signal states. A second issue of this work is
the presentation of a calculus of quantum information quantities, based on the
algebraic formulation of quantum theory.
| [
{
"version": "v1",
"created": "Mon, 6 Jul 1998 14:50:56 GMT"
},
{
"version": "v2",
"created": "Mon, 30 Nov 1998 14:35:14 GMT"
},
{
"version": "v3",
"created": "Thu, 1 Feb 2001 11:10:42 GMT"
}
] | 2016-11-15T00:00:00 | [
[
"Winter",
"Andreas",
""
]
] |
quant-ph/9807020 | Dr. Daniel A. Lidar | Christopher S. Maierle, Daniel A. Lidar, and Robert A. Harris (UC
Berkeley) | How to Teleport Superpositions of Chiral Amplitudes | Replaced with published version. Also available (in journal format)
at http://neon.cchem.berkeley.edu/~dani/abstract21.html | Phys. Rev. Lett. 81, 5928 (1998) | 10.1103/PhysRevLett.81.5928 | null | quant-ph | null | Chiral molecules may exist in superpositions of left- and right-handed
states. We show how the amplitudes of such superpositions may be teleported to
the polarization degrees of freedom of a photon and thus measured. Two
experimental schemes are proposed, one leading to perfect, the other to
state-dependent teleportation. Both methods yield complete information about
the amplitudes.
| [
{
"version": "v1",
"created": "Mon, 6 Jul 1998 20:16:52 GMT"
},
{
"version": "v2",
"created": "Mon, 21 Sep 1998 23:40:41 GMT"
},
{
"version": "v3",
"created": "Tue, 5 Jan 1999 01:32:37 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Maierle",
"Christopher S.",
"",
"UC\n Berkeley"
],
[
"Lidar",
"Daniel A.",
"",
"UC\n Berkeley"
],
[
"Harris",
"Robert A.",
"",
"UC\n Berkeley"
]
] |
quant-ph/9807021 | null | Ana M. Martins (Instituto Superior Tecnico, Lisboa, Portugal), Stefano
Mancini and Paolo Tombesi (Dpt. Matematica e Fisica, Univ. Camerino, Italy) | Electron-radiation interaction in a Penning trap: beyond the dipole
approximation | 12 pages, RevTeX, 6 figures, Approved for publication in Phys. Rev. A | Phys.Rev.A58:3813,1998 | 10.1103/PhysRevA.58.3813 | null | quant-ph | null | We investigate the physics of a single trapped electron interacting with a
radiation field without the dipole approximation. This gives new physical
insights in the so-called geonium theory.
| [
{
"version": "v1",
"created": "Wed, 8 Jul 1998 11:42:24 GMT"
}
] | 2011-08-04T00:00:00 | [
[
"Martins",
"Ana M.",
"",
"Instituto Superior Tecnico, Lisboa, Portugal"
],
[
"Mancini",
"Stefano",
"",
"Dpt. Matematica e Fisica, Univ. Camerino, Italy"
],
[
"Tombesi",
"Paolo",
"",
"Dpt. Matematica e Fisica, Univ. Camerino, Italy"
]
] |
quant-ph/9807022 | Anthony Chefles | Anthony Chefles | Unambiguous Discrimination Between Linearly-Independent Quantum States | null | Phys.Lett. A239 (1998) 339-347 | 10.1016/S0375-9601(98)00064-4 | null | quant-ph | null | The theory of generalised measurements is used to examine the problem of
discriminating unambiguously between non-orthogonal pure quantum states.
Measurements of this type never give erroneous results, although, in general,
there will be a non-zero probability of a result being inconclusive. It is
shown that only linearly-independent states can be unambiguously discriminated.
In addition to examining the general properties of such measurements, we
discuss their application to entanglement concentration.
| [
{
"version": "v1",
"created": "Wed, 8 Jul 1998 12:03:20 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Chefles",
"Anthony",
""
]
] |
quant-ph/9807023 | Anthony Chefles | Anthony Chefles and Stephen M. Barnett | Optimum Unambiguous Discrimination Between Linearly Independent
Symmetric States | 9 pages, 2 eps figures, submitted to Physics Letters A | Phys.Lett. A250 (1998) 223-229 | 10.1016/S0375-9601(98)00827-5 | null | quant-ph | null | The quantum formalism permits one to discriminate sometimes between any set
of linearly-independent pure states with certainty. We obtain the maximum
probability with which a set of equally-likely, symmetric, linearly-independent
states can be discriminated. The form of this bound is examined for symmetric
coherent states of a harmonic oscillator or field mode.
| [
{
"version": "v1",
"created": "Wed, 8 Jul 1998 12:19:00 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Chefles",
"Anthony",
""
],
[
"Barnett",
"Stephen M.",
""
]
] |
quant-ph/9807024 | Murray Holland | Murray Holland | Unraveling quantum dissipation in the frequency domain | 4 pages, 4 Postscript figures, uses RevTeX | Phys.Rev.Lett. 81 (1998) 5117-5120 | 10.1103/PhysRevLett.81.5117 | null | quant-ph | null | We present a quantum Monte Carlo method for solving the evolution of an open
quantum system. In our approach, the density operator evolution is unraveled in
the frequency domain. Significant advantages of this approach arise when the
frequency of each dissipative event conveys information about the state of the
system.
| [
{
"version": "v1",
"created": "Wed, 8 Jul 1998 18:08:40 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Holland",
"Murray",
""
]
] |
quant-ph/9807025 | Taras Kuliy | T. V. Kuliy and V. M. Tkachuk | Quasi-Exactly Solvable Potentials with Three Known Eigenstates | 15 pages, LaTeX, no figures, revised version | J.Phys.A32:2157-2169,1999 | 10.1088/0305-4470/32/11/010 | null | quant-ph math-ph math.MP | null | We propose a new SUSY method for construction of the quasi-exactly solvable
(QES) potentials with three known eigenstates. New QES potentials and
corresponding energy levels and wave functions of the ground state and two
lowest excited state are obtained. The proposed scheme allows also to construct
families of exactly solvable non-singular potentials which are SUSY partners of
the well-known ones.
| [
{
"version": "v1",
"created": "Thu, 9 Jul 1998 20:40:20 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jan 1999 17:46:14 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Kuliy",
"T. V.",
""
],
[
"Tkachuk",
"V. M.",
""
]
] |
quant-ph/9807026 | Michael R. Dunlavey | M. R. Dunlavey | Simulation of finite state machines in a quantum computer | Plain TEX, 6 pages, 3 GIF figures, includes C program | null | null | null | quant-ph | null | A construction is given for simulating any deterministic finite state machine
(FSM) on a quantum computer in a space-efficient manner. By constructing a
superposition of input strings of lengths K or less, questions can be asked
about the FSM, such as the inputs that reach particular nodes, and the answers
can be found using a search algorithm such as Grover's. This has implications
for the eventual utility of quantum computers for software validation.
| [
{
"version": "v1",
"created": "Thu, 9 Jul 1998 15:05:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Dunlavey",
"M. R.",
""
]
] |
quant-ph/9807027 | Dr. Daniel A. Lidar | Eli Biham (1), Ofer Biham (2), David Biron (2), Markus Grassl (3) and
Daniel A. Lidar (4) ((1) Technion, Haifa, (2) Hebrew University, Jerusalem,
(3) Karlsruhe University, Germany, (4) UC Berkeley) | Grover's Quantum Search Algorithm for an Arbitrary Initial Amplitude
Distribution | 5 pages, no figures. This paper generalizes the results of
http://xxx.lanl.gov/abs/quant-ph/9801066 (quant-ph/9801066) to the case of
complex amplitudes and the case of an unknown initial amplitude distribution.
Some changes in this final version. To appear in Phys. Rev. A | Phys.Rev. A60 (1999) 2742 | 10.1103/PhysRevA.60.2742 | null | quant-ph | null | Grover's algorithm for quantum searching is generalized to deal with
arbitrary initial complex amplitude distributions. First order linear
difference equations are found for the time evolution of the amplitudes of the
marked and unmarked states. These equations are solved exactly. New expressions
are derived for the optimal time of measurement and the maximal probability of
success. They are found to depend on the averages and variances of the initial
amplitude distributions of the marked and unmarked states, but not on higher
moments. Our results imply that Grover's algorithm is robust against modest
noise in the amplitude initialization procedure.
| [
{
"version": "v1",
"created": "Thu, 9 Jul 1998 15:14:14 GMT"
},
{
"version": "v2",
"created": "Mon, 21 Jun 1999 19:25:01 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Biham",
"Eli",
""
],
[
"Biham",
"Ofer",
""
],
[
"Biron",
"David",
""
],
[
"Grassl",
"Markus",
""
],
[
"Lidar",
"Daniel A.",
""
]
] |
quant-ph/9807028 | Michael Jack | M. W. Jack, M. J. Collett, and D. F. Walls | Non-Markovian quantum trajectories for spectral detection | null | null | 10.1103/PhysRevA.59.2306 | null | quant-ph | null | We present a formulation of non-Markovian quantum trajectories for open
systems from a measurement theory perspective. In our treatment there are three
distinct ways in which non-Markovian behavior can arise; a mode dependent
coupling between bath (reservoir) and system, a dispersive bath, and by
spectral detection of the output into the bath. In the first two cases the
non-Markovian behavior is intrinsic to the interaction, in the third case the
non-Markovian behavior arises from the method of detection. We focus in detail
on the trajectories which simulate real-time spectral detection of the light
emitted from a localized system. In this case, the non-Markovian behavior
arises from the uncertainty in the time of emission of particles that are later
detected. The results of computer simulations of the spectral detection of the
spontaneous emission from a strongly driven two-level atom are presented.
| [
{
"version": "v1",
"created": "Fri, 10 Jul 1998 10:14:51 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Jack",
"M. W.",
""
],
[
"Collett",
"M. J.",
""
],
[
"Walls",
"D. F.",
""
]
] |
quant-ph/9807029 | Peter Hoyer | Mark Ettinger (LANL) and Peter Hoyer (Odense University) | On Quantum Algorithms for Noncommutative Hidden Subgroups | 13 pages, no figures, LaTeX2e | Proceedings of 16th Annual Symposium on Theoretical Aspects of
Computer Science (STACS), Trier, Germany, pp. 478-487, 1999 | 10.1007/3-540-49116-3_45 | LA-UR-98-2010 (May 6, 1998) | quant-ph | null | Quantum algorithms for factoring and discrete logarithm have previously been
generalized to finding hidden subgroups of finite Abelian groups. This paper
explores the possibility of extending this general viewpoint to finding hidden
subgroups of noncommutative groups. We present a quantum algorithm for the
special case of dihedral groups which determines the hidden subgroup in a
linear number of calls to the input function. We also explore the difficulties
of developing an algorithm to process the data to explicitly calculate a
generating set for the subgroup. A general framework for the noncommutative
hidden subgroup problem is discussed and we indicate future research
directions.
| [
{
"version": "v1",
"created": "Fri, 10 Jul 1998 20:14:50 GMT"
}
] | 2015-06-02T00:00:00 | [
[
"Ettinger",
"Mark",
"",
"LANL"
],
[
"Hoyer",
"Peter",
"",
"Odense University"
]
] |
quant-ph/9807030 | Pawel Horodecki | Pawe{\l} Horodecki | "Interaction--free'' interaction: entangling evolution via quantum Zeno
effect | 4 pages, RevTeX | null | null | null | quant-ph | null | The effect of entangling evolution induced by frequently repeated quantum
measurement is presented. The interesting possibility of conditional freezing
the system in maximally entangled state out of Zeno effect regime is also
revealed. The illustration of the phenomena in terms of dynamical version of
``interaction free'' measurement is presented. Some general conclusions are
provided.
| [
{
"version": "v1",
"created": "Sat, 11 Jul 1998 19:03:37 GMT"
}
] | 2016-08-15T00:00:00 | [
[
"Horodecki",
"Paweł",
""
]
] |
quant-ph/9807031 | Safonov S. S. | Sergey S. Safonov (Moscow Institute of Physics and Technology) | Tomography of Quantum Spinor States | 10 pages, LaTeX 2.09, 2 PostScript figures, Contribution to the XVI
International Conference on Coherent and Nonlinear Optics, Moscow, 1998.
(replaced: incorrect TeX commands) | null | null | null | quant-ph | null | A possibility of describing two-level atom states in terms of positive
probability distributions (analog to the symplectic tomography scheme) is
considered. As a result the basis of the irreducible representation of a
rotation group can be realized by a family of the probability distributions of
the spin projection parametrized by points on the sphere. Furthermore the
tomography of rotational states of molecules and nuclei which can be described
by the model of a symmetric top is discussed.
| [
{
"version": "v1",
"created": "Mon, 13 Jul 1998 07:50:16 GMT"
},
{
"version": "v2",
"created": "Wed, 15 Jul 1998 09:24:45 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Safonov",
"Sergey S.",
"",
"Moscow Institute of Physics and Technology"
]
] |
quant-ph/9807032 | Paul Benioff | Paul Benioff (Argonne National Laboratory) | Quantum Robots Plus Environments | 10 pages Latex, 1 postscript figure | null | null | null | quant-ph | null | A quantum robot is a mobile quantum system including an on bord quantum
computer and ancillary systems, that interact with an environment of quantum
systems. Quantum robots carry out tasks whose goals include carrying out
measurements and physical experiments on the environment. Environments
considered so far in the literature: oracles, data bases, and quantum
registers, are shown to be special cases of environments considered here. It is
noted that quantum robots should include a quantum computer and cannot be
simply a multistate head. A model is discussed in which each task, as a
sequence of computation and action phases, is described by a unitary step
operator. Overall system dynamics is described in terms of a Feynman sum over
paths of completed computation and action phases. A simple task example,
measuring the distance between the quantum robot and a particle on a 1D space
lattice, with quantum phase path and time duration dispersion present, is
analyzed.
| [
{
"version": "v1",
"created": "Mon, 13 Jul 1998 16:26:33 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Benioff",
"Paul",
"",
"Argonne National Laboratory"
]
] |
quant-ph/9807033 | Norman Dombey | A Calogeracos and N Dombey | The Continuum Limit and Integral Vacuum Charge | 5 pages. Submitted to JETP Letters | JETP Lett. 68 (1998) 377-382; Pisma Zh.Eksp.Teor.Fiz. 68 (1998)
353-358 | 10.1134/1.567876 | null | quant-ph | null | We investigate a commonly used formula which seems to give non-integral
vacuum charge in the continuum limit. We show that the limit is subtle and care
must be taken to get correct results.
| [
{
"version": "v1",
"created": "Mon, 13 Jul 1998 17:03:20 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Calogeracos",
"A",
""
],
[
"Dombey",
"N",
""
]
] |
quant-ph/9807034 | Jens Eisert | J. Eisert (U. Potsdam, Germany), M. B. Plenio (Imperial College,
London, U.K.) | A comparison of entanglement measures | 6 pages (RevTeX), 4 figures | J. Mod. Opt. 46, 145 (1999) | 10.1080/09500349908231260 | J. Mod. Opt. 46, 145-154 (1999) | quant-ph | null | We compare the entanglement of formation with a measure defined as the
modulus of the negative eigenvalue of the partial transpose. In particular, we
investigate whether both measures give the same ordering of density operators
with respect to the amount of entanglement.
| [
{
"version": "v1",
"created": "Mon, 13 Jul 1998 20:09:30 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Mar 1999 10:56:20 GMT"
}
] | 2020-11-19T00:00:00 | [
[
"Eisert",
"J.",
"",
"U. Potsdam, Germany"
],
[
"Plenio",
"M. B.",
"",
"Imperial College,\n London, U.K."
]
] |
quant-ph/9807035 | Wang Zhen | Zhen Wang | What is in One: Uncertainty quantum and Continuum Hypothesis | LaTex, 5 pages, no figure | null | null | LNU-98-07 | quant-ph | null | The concept of measurement is discussed. It is argued that counting process
in mathematics is also measurement which requires a basic unit. The idea of
scale is put forward. The basic unit itself, which are composed of the
infinitesimal of uncertainty quantum, can be regarded as infinite in another
scale. Thus infinite, infinitesimal and integer " 1 " are unified. It is
proposed that multiplication changes to summation when it is transformed to a
larger scale. The Continuum Hypothesis is proved to be correct after a scale
transformation.
| [
{
"version": "v1",
"created": "Tue, 14 Jul 1998 07:58:56 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Wang",
"Zhen",
""
]
] |
quant-ph/9807036 | Brosens | J. Tempere, F. Brosens, L. F. Lemmens, J. T. Devreese | Momentum distribution of confined bosons: temperature dependence | 5 REVTEX pages + 2 postscript figures. Accepted in Phys. Rev. A | Phys.Rev. A58 (1998) 3180 | 10.1103/PhysRevA.58.3180 | null | quant-ph | null | The momentum distribution function of a parabolically confined gas of bosons
with harmonic interparticle interactions is derived. In the Bose-Einstein
condensation region, this momentum distribution substantially deviates from a
Maxwell-Boltzmann distribution. It is argued that the determination of the
temperature of the boson gas from the Bose-Einstein momentum distribution
function is more appropriate than the currently used fitting to the high
momentum tail of the Maxwell-Boltzmann distribution.
| [
{
"version": "v1",
"created": "Tue, 14 Jul 1998 13:10:31 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Tempere",
"J.",
""
],
[
"Brosens",
"F.",
""
],
[
"Lemmens",
"L. F.",
""
],
[
"Devreese",
"J. T.",
""
]
] |
quant-ph/9807037 | R. E. Kastner | R. E. Kastner | The Three-Box "Paradox" and Other Reasons to Reject the Counterfactual
Usage of the ABL Rule | 20 pages, Latex, 2 figures (in three files). To appear in Foundations
of Physics. Title changed, further arguments and appendix added | Found.Phys. 29 (1999) 851-863 | null | null | quant-ph | null | An apparent paradox proposed by Aharonov and Vaidman in which a single
particle can be found with certainty in two (or more) boxes is analyzed by way
of a simple thought experiment. It is found that the apparent paradox arises
from an invalid counterfactual usage of the Aharonov-Bergmann-Lebowitz (ABL)
rule, and effectively attributes conflicting properties not to the same
particle but to different particles. A connection is made between the present
analysis and the consistent histories formulation of Griffiths. Finally, a
critique is given of some recent counterarguments by
Vaidman against the rejection of the counterfactual usage of the ABL rule.
| [
{
"version": "v1",
"created": "Tue, 14 Jul 1998 14:52:52 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Jul 1998 16:47:28 GMT"
},
{
"version": "v3",
"created": "Wed, 10 Feb 1999 07:24:50 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Kastner",
"R. E.",
""
]
] |
quant-ph/9807038 | Holger F. Hofmann | Holger F. Hofmann, Ortwin Hess and Guenter Mahler | Quantum control of atomic systems by time-resolved homodyne detection of
spontaneous emission | 5 pages Latex, contribution to the proceedings of the ISQM98
conference held August 24th to 27th in Tokyo | Quantum Coherence and Decoherence, edited by Y.A. Ono and K.
Fujikawa, Elsevier 1999 | null | null | quant-ph physics.atom-ph physics.optics | null | We describe the light-matter interaction of a single two level atom with the
electromagnetic vacuum in terms of field and dipole variables by considering
homodyne detection of the emitted fields. Spontaneous emission is then observed
as a continuous fluctuating force acting on the atomic dipole. The effect of
this force may be compensated and even reversed by feedback.
| [
{
"version": "v1",
"created": "Tue, 14 Jul 1998 15:27:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hofmann",
"Holger F.",
""
],
[
"Hess",
"Ortwin",
""
],
[
"Mahler",
"Guenter",
""
]
] |
quant-ph/9807039 | Jezykmil | Piotr Milczarski (Theoretical Physics Department II, University of
Lodz, Poland) | Exactness of Conventional and Supersymmetric JWKB Formulae and Glo bal
Symmetries of Stokes Graphs | 62 pages, 17 EPS figuures | null | null | null | quant-ph | null | It has been shown that the cases of the JWKB formulae in 1--dim QM quantizing
the energy levels exactly are results of essentially one global symmetry of
both potentials and their corresponding Stokes graphs. Namely, this is the
invariance of the latter on translations in the complex plain of the space
variable i.e. the potentials and the Stokes graphs have to be periodic. A
proliferation of turning points in the basic period strips (parallelograms) is
another limitation for the exactness of the JWKB formulae. A systematic
analyses of a single-well class of potentials satisfying suitable conditions
has been performed. Only ten potentials (with one or two real parameters)
quantized exactly by the JWKB formulae have been found all of them coinciding
(or being equivalent to) with the well-known ones found previously. It was
shown also that the exactness of the supersymmetric JWKB formulae is a
consequence of the corresponding exactness of the conventional ones and vice
versa. Because of the latter two exactly JWKB quantized potentials have been
additionally established. These results show that the exact SUSY JWKB formulae
choose the Comtet at al form of them independently of whether the supersymmetry
is broken or not. A close relation between the shape invariance property of
potentials considered and their meromorphic structure on the x-plane is also
demonstrated.
| [
{
"version": "v1",
"created": "Tue, 14 Jul 1998 17:49:52 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Milczarski",
"Piotr",
"",
"Theoretical Physics Department II, University of\n Lodz, Poland"
]
] |
quant-ph/9807040 | null | Ph. Blanchard, M. Pasquini, M. Serva (Fakult\"at f\"ur Physik,
Universit\"at Bielefeld, Germany, I.N.F.M. and Dipartimento di Matematica,
Universit\`a dell'Aquila, Italy) | Localization induced by noise and non linearity | 12 pages, RevTeX, psfig.sty, 2 ps figures, submitted to Phys. Rev.
Lett | Physica D141 (2000) 214-220 | 10.1016/S0167-2789(00)00036-1 | null | quant-ph | null | We introduce a model for a two configurations system, and we study the
transition from quantum to classical behaviour. We first consider the effect of
the interaction with the environment as an external noise and we show that it
produces decoherence and suppression of tunnelling. These features are widely
accepted as definition of classicality, while we believe that classicality
implies that quantum delocalized states spontaneously evolve into localized
ones. We than show that this evolution take place only when both noise and non
linearity in the equations are present.
| [
{
"version": "v1",
"created": "Wed, 15 Jul 1998 17:28:35 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Blanchard",
"Ph.",
"",
"Fakultät für Physik,\n Universität Bielefeld, Germany, I.N.F.M. and Dipartimento di Matematica,\n Università dell'Aquila, Italy"
],
[
"Pasquini",
"M.",
"",
"Fakultät für Physik,\n Universität Bielefeld, Germany, I.N.F.M. and Dipartimento di Matematica,\n Università dell'Aquila, Italy"
],
[
"Serva",
"M.",
"",
"Fakultät für Physik,\n Universität Bielefeld, Germany, I.N.F.M. and Dipartimento di Matematica,\n Università dell'Aquila, Italy"
]
] |
quant-ph/9807041 | Nicolas Gisin | H. Bechmann-Pasquinucci and N. Gisin | Incoherent and Coherent Eavesdropping in the 6-state Protocol of Quantum
Cryptography | 17 pages, 4 figures: Updated version, discussion on error correction
and privacy amplification added | Phys. Rev. A, 59, 4238-4248, 1999 | 10.1103/PhysRevA.59.4238 | null | quant-ph | null | All incoherent as well as 2- and 3-qubit coherent eavesdropping strategies on
the 6 state protocol of quantum cryptography are classified. For a disturbance
of 1/6, the optimal incoherent eavesdropping strategy reduces to the universal
quantum cloning machine. Coherent eavesdropping cannot increase Eve's Shannon
information, neither on the entire string of bits, nor on the set of bits
received undisturbed by Bob. However, coherent eavesdropping can increase as
well Eve's Renyi information as her probability of guessing correctly all bits.
The case that Eve delays the measurement of her probe until after the public
discussion on error correction and privacy amplification is also considered. It
is argued that by doing so, Eve gains only a negligibly small additional
information.
| [
{
"version": "v1",
"created": "Thu, 16 Jul 1998 13:02:26 GMT"
},
{
"version": "v2",
"created": "Sun, 20 Dec 1998 14:04:20 GMT"
}
] | 2013-01-22T00:00:00 | [
[
"Bechmann-Pasquinucci",
"H.",
""
],
[
"Gisin",
"N.",
""
]
] |
quant-ph/9807042 | Chiao | Raymond Y. Chiao and John C. Garrison (UC Berkeley) | Realism or Locality: Which Should We Abandon? | 10 pages, 0 figures, to appear in Foundations of Physics | Found.Phys. 29 (1999) 553-560 | null | UCB-98-07 | quant-ph | null | We reconsider the consequences of the observed violations of Bell's
inequalities. Two common responses to these violations are: (i) the rejection
of realism and the retention of locality, and (ii) the rejection of locality
and the retention of realism. Here we critique response (i). We argue that
locality contains an implicit form of realism, since in a world view that
embraces locality, spacetime, with its usual, fixed topology, has properties
independent of measurement. Hence we argue that response (i) is incomplete, in
that its rejection of realism is only partial.
| [
{
"version": "v1",
"created": "Thu, 16 Jul 1998 18:28:48 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Jul 1998 21:27:11 GMT"
},
{
"version": "v3",
"created": "Thu, 23 Jul 1998 19:21:22 GMT"
},
{
"version": "v4",
"created": "Mon, 17 Aug 1998 20:25:50 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Chiao",
"Raymond Y.",
"",
"UC Berkeley"
],
[
"Garrison",
"John C.",
"",
"UC Berkeley"
]
] |
quant-ph/9807043 | Jonathan Oppenheim | J. Oppenheim, B. Reznik, W.G. Unruh | Time-of-Arrival States | 15 pages, 2 figures | Phys.Rev. A59 (1999) 1804 | 10.1103/PhysRevA.59.1804 | null | quant-ph gr-qc | null | Although one can show formally that a time-of-arrival operator cannot exist,
one can modify the low momentum behaviour of the operator slightly so that it
is self-adjoint. We show that such a modification results in the difficulty
that the eigenstates are drastically altered. In an eigenstate of the modified
time-of-arrival operator, the particle, at the predicted time-of-arrival, is
found far away from the point of arrival with probability 1/2.
| [
{
"version": "v1",
"created": "Fri, 17 Jul 1998 21:55:04 GMT"
}
] | 2009-10-31T00:00:00 | [
[
"Oppenheim",
"J.",
""
],
[
"Reznik",
"B.",
""
],
[
"Unruh",
"W. G.",
""
]
] |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.