Quantum discord and its dynamics for multipartite systems

Abstract

Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et.al. In this paper, we give analytical solutions of the quantum discord for a family of N-qubit quantum states. For bipartite case, we derive a zero quantum discord which will remain unchanged under the phase damping channel. For larger cases, it is found that the quantum discord can be classified into three categories and the quantum discord for odd-partite systems can exhibit freezing under the phase damping channel, while the freezing doesn't exist in the even-partite systems.