Role of an information-theoretic measure of quantum correlation in a dynamical phase transition of entanglement

摘要

The nearest-neighbor entanglement of the evolved state of an asymmetric quantum XY spin chain, in a transverse time dependent field, exhibits criticalities (dynamical phase transitions) as the initial field parameter is varied at a given fixed time. After a discussion of the dynamical phase transition, we investigate the extent to which the role of an information theoretic quantum correlation measure, called quantum discord, can be used to understand the entanglement dynamics in this spin model. We show that quantum discord can be associated with the collapse and revival of nearest-neighbor entanglement exhibited in the critical behavior. This behavior of quantum discord leads to the broader question of whether certain classes of measures of nonclassical correlation can help to understand the non-generic features of entanglement in a given system.