25,654 research outputs found
Condition for tripartite entanglement
We propose a scheme for classifying the entanglement of a tripartite pure
qubit state. This classification scheme consists of an ordered list of seven
elements. These elements are the Cayley hyper-determinant, and its six
associated subdeterminants. In particular we show that this
classification provides a necessary and sufficient condition for separability.Comment: 8 pages, to appear in the Proceedings of "Quantum Theory and
Symmetries 7", Prague, Aug 7-13, 201
Effect of disorder on a Pomeranchuk instability
We study the effect of disorder on the order parameter equation and
transition temperature of a Pomeranchuk-type Fermi-surface instability using
replica mean field theory. We consider the example of a phase transition to a
type Fermi surface distortion, and show that, in the regime
where such a transition is second order, the transition temperature is reduced
by disorder in essentially the same way as that for a d-wave superconductor. We
argue that observing this disorder dependence of metal-to-metal transition
might be a useful indicator of a finite angular momentum Fermi surface
distortion.Comment: 4.1 pages, 3 figs. Version as published in EPL. Added data of
Sr3Ru2O7 to theory curves of Fig.2, and some clarification of derivation of
result
Third-order many-body perturbation theory calculations for the beryllium and magnesium isoelectronic sequences
Relativistic third-order MBPT is applied to obtain energies of ions with two
valence electrons in the no virtual-pair approximation (NVPA). A total of 302
third-order Goldstone diagrams are organized into 12 one-body and 23 two-body
terms. Only third-order two-body terms and diagrams are presented here, owing
to the fact that the one-body terms are identical to the previously studied
third-order terms in monovalent ions. Dominant classes of diagrams are
identified. The model potential is a Dirac-Hartree-Fock potential,
and B-spline basis functions in a cavity of finite radius are employed in the
numerical calculations. The Breit interaction is taken into account through
second order of perturbation theory and the lowest-order Lamb shift is also
evaluated. Sample calculations are performed for berylliumlike ions with Z =
4--7, and for the magnesiumlike ion P IV. The third-order energies are in
excellent agreement with measurement with an accuracy at 0.2% level for the
cases considered. Comparisons are made with previous second-order MBPT results
and with other calculations. The third-order energy correction is shown to be
significant, improving second-order correlation energies by an order of
magnitude
Generalized Rayleigh and Jacobi processes and exceptional orthogonal polynomials
We present four types of infinitely many exactly solvable Fokker-Planck
equations, which are related to the newly discovered exceptional orthogonal
polynomials. They represent the deformed versions of the Rayleigh process and
the Jacobi process.Comment: 17 pages, 4 figure
The fluctuation spectra around a Gaussian classical solution of a tensor model and the general relativity
Tensor models can be interpreted as theory of dynamical fuzzy spaces. In this
paper, I study numerically the fluctuation spectra around a Gaussian classical
solution of a tensor model, which represents a fuzzy flat space in arbitrary
dimensions. It is found that the momentum distribution of the low-lying
low-momentum spectra is in agreement with that of the metric tensor modulo the
general coordinate transformation in the general relativity at least in the
dimensions studied numerically, i.e. one to four dimensions. This result
suggests that the effective field theory around the solution is described in a
similar manner as the general relativity.Comment: 29 pages, 13 figure
Electromagnetic Structure of the Meson in the Light-Front Quark Model
We investigate the elastic form factors of the rho meson in the light-front
quark model(LFQM). With the phenomenologically accessible meson vertices
including the one obtained by the Melosh transformation frequently used in the
LFQM, we find that only the helicity matrix element of the plus
current receives the zero-mode contribution. We quantify the zero-mode
contribution in the helicity amplitude using the angular condition of
spin-1 system. After taking care of the zero-mode issue, we obtain the
magnetic() and quadrupole() moments of the rho meson as and
, respectively, in the LFQM consistent with the Melosh transformation
and compare our results with other available theoretical predictions.Comment: 14pages, 5figure
Distribution amplitudes and decay constants for mesons in light-front quark model
We present a calculation of the quark distribution amplitudes(DAs), the
Gegenbauer moments, and decay constants for and mesons using
the light-front quark model. While the quark DA for is somewhat broader
than the asymptotic one, that for meson is very close to the asymptotic
one. The quark DAs for and show asymmetric form due to the flavor
SU(3)-symmetry breaking effect. The decay constants for the transversely
polarized and mesons( and ) as well as the
longitudinally polarized ones( and ) are also obtained. Our
averaged values for , i.e. and
, are found to be consistent with other
model predictions. Especially, our results for the decay constants are in a
good agreement with the SU(6) symmetry relation,
.Comment: 12 pages, 6figure
- …