Reveal quantum correlation in complementary bases

An essential feature of genuine quantum correlation is the simultaneous existence of correlation in complementary bases. We reveal this feature of quantum correlation by defining measures based on invariance under a basis change. For a bipartite quantum state, the classical correlation is the maximal correlation present in a certain optimum basis, while the quantum correlation is characterized as a series of residual correlations in the mutually unbiased bases. Compared with other approaches to quantify quantum correlation, our approach gives information-theoretical measures that directly reflect the essential feature of quantum correlation.Comment: 7 pages, 4 figure

Stability analysis of a ratio-dependent predator-prey system with diffusion and stage structure

A two-species predator-prey system with diffusion term and stage structure is discussed, local stability of the system is studied using linearization method, and global stability of the system is investigated by strong upper and lower solutions. The asymptotic behavior of solutions and the negative effect of stage structure on the permanence of populations are given