Generalized entropic measures of quantum correlations in spin chains

N. CANOSA; L. CILIBERTI; R. ROSSIGNOLI

Maceió, Alagoas, Brasil

Conferencia; MEDYFINOL 2014 XVIII Conference on Nonequilibrium Statistical Mechanics and Nonlinear Physics; 2014

CNPq

We examine non-classical correlations in spin 1/2 chains in an applied transverse field, through the analysis of information measures based on generalized entropic forms. These measures comprise the quantum discord on one side, and the one-way information deficit, the geometric discord and the q-type information deficit on the other. It is shown [1] that all these quantities provide the same qualitative information. In the case of Heisenberg-type XX chains, they all reach full range in the vicinity of the critical field Bc, and decay smoothly with temperature. Moreover, they exhibit similar asymptotic behaviors for high temperatures or large separations between the pair. Nonetheless, it is also shown that important differences arise in the minimizing local measurement that defines them. The information deficit based measures exhibit a measurement transition, absent in the quantum discord, which reflects significant changes in the structure of the reduced pair state. [1] L. Ciliberti, N. Canosa, R. Rossignoli, Phys. Rev. A 88, 012119 (2013).