419 research outputs found
Hamilton-Jacobi Formulation of KS Entropy for Classical and Quantum Dynamics
A Hamilton-Jacobi formulation of the Lyapunov spectrum and KS entropy is
developed. It is numerically efficient and reveals a close relation between the
KS invariant and the classical action. This formulation is extended to the
quantum domain using the Madelung-Bohm orbits associated with the Schroedinger
equation. The resulting quantum KS invariant for a given orbit equals the mean
decay rate of the probability density along the orbit, while its ensemble
average measures the mean growth rate of configuration-space information for
the quantum system.Comment: preprint, 8 pages (revtex
Correlative Capacity of Composite Quantum States
We characterize the optimal correlative capacity of entangled, separable, and
classically correlated states. Introducing the notions of the infimum and
supremum within majorization theory, we construct the least disordered
separable state compatible with a set of marginals. The maximum separable
correlation information supportable by the marginals of a multi-qubit pure
state is shown to be an LOCC monotone. The least disordered composite of a pair
of qubits is found for the above classes, with classically correlated states
defined as diagonal in the product of marginal bases.Comment: 4 pages, 1 figur
Structure and Dynamics of the Instantaneous Water/Vapor Interface Revisited by Path-Integral and Ab-Initio Molecular Dynamics Simulations
The structure and dynamics of the water/vapor interface is revisited by means
of path-integral and second-generation Car-Parrinello ab-initio molecular
dynamics simulations in conjunction with an instantaneous surface definition
[A. P. Willard and D. Chandler, J. Phys. Chem. B 114, 1954 (2010)]. In
agreement with previous studies, we find that one of the OH bonds of the water
molecules in the topmost layer is pointing out of the water into the vapor
phase, while the orientation of the underlying layer is reversed. Therebetween,
an additional water layer is detected, where the molecules are aligned parallel
to the instantaneous water surface.Comment: 9 pages, 5 figure
Entanglement Detection Using Majorization Uncertainty Bounds
Entanglement detection criteria are developed within the framework of the
majorization formulation of uncertainty. The primary results are two theorems
asserting linear and nonlinear separability criteria based on majorization
relations, the violation of which would imply entanglement. Corollaries to
these theorems yield infinite sets of scalar entanglement detection criteria
based on quasi-entropic measures of disorder. Examples are analyzed to probe
the efficacy of the derived criteria in detecting the entanglement of bipartite
Werner states. Characteristics of the majorization relation as a comparator of
disorder uniquely suited to information-theoretical applications are emphasized
throughout.Comment: 10 pages, 1 figur
Effects of Mentha pulegium water extract dipping on quality and shelf life of silver carp (Hypophthalmichthys molitrix) during superchilled storage
The effects of Mentha pulegium water extract dipping on quality and shelf life of silver carp during superchilled storage were investigated. Fish samples were treated with water extract of 1 and 3% M. pulegium, and then stored at -3 οC for 30 days. The control and the treated fish samples were analyzed periodically for chemical (pH, PV, TBA, TVB-N), and sensory characteristics. The results indicated that the effect of M. pulegium extract dipping on fish samples was to retain their good quality characteristics and extend the shelf life during superchilled storage, which was supported by the results of chemical and sensory evaluation analyses. In this respect, the sample supplemented with 3% water extract was more potent compared with the 1% one in extending the shelf life of fish fillets
Stable ultrahigh-density magneto-optical recordings using introduced linear defects
The stability of data bits in magnetic recording media at ultrahigh densities
is compromised by thermal `flips' -- magnetic spin reversals -- of nano-sized
spin domains, which erase the stored information. Media that are magnetized
perpendicular to the plane of the film, such as ultrathin cobalt films or
multilayered structures, are more stable against thermal self-erasure than
conventional memory devices. In this context, magneto-optical memories seem
particularly promising for ultrahigh-density recording on portable disks, and
bit densities of 100 Gbit inch have been demonstrated using recent
advances in the bit writing and reading techniques. But the roughness and
mobility of the magnetic domain walls prevents closer packing of the magnetic
bits, and therefore presents a challenge to reaching even higher bit densities.
Here we report that the strain imposed by a linear defect in a magnetic thin
film can smooth rough domain walls over regions hundreds of micrometers in
size, and halt their motion. A scaling analysis of this process, based on the
generic physics of disorder-controlled elastic lines, points to a simple way by
which magnetic media might be prepared that can store data at densities in
excess of 1 Tbit inch.Comment: 5 pages, 4 figures, see also an article in TRN News at
http://www.trnmag.com/Stories/041801/Defects_boost_disc_capacity_041801.htm
QED Corrections to Planck's Radiation Law and Photon Thermodynamics
Leading corrections to Planck's formula and photon thermodynamics arising
from the pair-mediated photon-photon interaction are calculated. This
interaction is attractive and causes an increase in occupation number for all
modes. Possible consequences, including the role of the cosmic photon gas in
structure formation, are considered.Comment: 15 pages, Revtex 3.
How to obtain a covariant Breit type equation from relativistic Constraint Theory
It is shown that, by an appropriate modification of the structure of the
interaction potential, the Breit equation can be incorporated into a set of two
compatible manifestly covariant wave equations, derived from the general rules
of Constraint Theory. The complementary equation to the covariant Breit type
equation determines the evolution law in the relative time variable. The
interaction potential can be systematically calculated in perturbation theory
from Feynman diagrams. The normalization condition of the Breit wave function
is determined. The wave equation is reduced, for general classes of potential,
to a single Pauli-Schr\"odinger type equation. As an application of the
covariant Breit type equation, we exhibit massless pseudoscalar bound state
solutions, corresponding to a particular class of confining potentials.Comment: 20 pages, Late
Universal Measure of Entanglement
A general framework is developed for separating classical and quantum
correlations in a multipartite system. Entanglement is defined as the
difference in the correlation information encoded by the state of a system and
a suitably defined separable state with the same marginals. A generalization of
the Schmidt decomposition is developed to implement the separation of
correlations for any pure, multipartite state. The measure based on this
decomposition is a generalization of the entanglement of formation to
multipartite systems, provides an upper bound for the relative entropy of
entanglement, and is directly computable on pure states. The example of pure
three-qubit states is analyzed in detail, and a classification based on
minimal, four-term decompositions is developed.Comment: 4 page
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