Multipartite quantum correlation and entanglement in four-qubit pure states

Based on the quantitative complementarity relations, we analyze thoroughly the properties of multipartite quantum correlations and entanglement in four-qubit pure states. We find that, unlike the three-qubit case, the single residual correlation, the genuine three- and four-qubit correlations are not suited to quantify entanglement. More interestingly, from our qualitative and numerical analysis, it is conjectured that the sum of all the residual correlations may constitute a good measure for the total multipartite entanglement in the system.Comment: 7 pages, 3 figue

Multipartite entanglement in four-qubit cluster-class states

Based on quantitative complementarity relations (QCRs), we analyze the multipartite correlations in four-qubit cluster-class states. It is proven analytically that the average multipartite correlation $E_{ms}$ is entanglement monotone. Moreover, it is also shown that the mixed three-tangle is a correlation measure compatible with the QCRs in this kind of quantum states. More arrestingly, with the aid of the QCRs, a set of hierarchy entanglement measures is obtained rigorously in the present system.Comment: 7 pages, 3 figs, version 3, some refs. are adde

A two component jet model for the X-ray afterglow flat segment in short GRB 051221A

In the double neutron star merger or neutron star-black hole merger model for short GRBs, the outflow launched might be mildly magnetized and neutron rich. The magnetized neutron-rich outflow will be accelerated by the magnetic and thermal pressure and may form a two component jet finally, as suggested by Vlahakis, Peng & K\"{o}nigl (2003). We show in this work that such a two component jet model could well reproduce the multi-wavelength afterglow lightcurves, in particular the X-ray flat segment, of short GRB 051221A. In this model, the central engine need not to be active much longer than the prompt $\gamma-$ray emission.Comment: 11 pages, 2 figure; Accepted for publication by ApJ

A parity-breaking electronic nematic phase transition in the spin-orbit coupled metal Cd2_2Re2_2O7_7

Strong electron interactions can drive metallic systems toward a variety of well-known symmetry-broken phases, but the instabilities of correlated metals with strong spin-orbit coupling have only recently begun to be explored. We uncovered a multipolar nematic phase of matter in the metallic pyrochlore Cd$_2$Re$_2$O$_7$ using spatially resolved second-harmonic optical anisotropy measurements. Like previously discovered electronic nematic phases, this multipolar phase spontaneously breaks rotational symmetry while preserving translational invariance. However, it has the distinguishing property of being odd under spatial inversion, which is allowed only in the presence of spin-orbit coupling. By examining the critical behavior of the multipolar nematic order parameter, we show that it drives the thermal phase transition near 200 kelvin in Cd$_2$Re$_2$O$_7$ and induces a parity-breaking lattice distortion as a secondary order.Comment: 9 pages main text, 4 figures, 10 pages supplementary informatio

Quantum state redistribution based on a generalized decoupling

We develop a simple protocol for a one-shot version of quantum state redistribution, which is the most general two-terminal source coding problem. The protocol is simplified from a combination of protocols for the fully quantum reverse Shannon and fully quantum Slepian-Wolf problems, with its time-reversal symmetry being apparent. When the protocol is applied to the case where the redistributed states have a tensor power structure, more natural resource rates are obtained