Geometric global quantum discord of two-qubit states**Project supported by the National Natural Science Foundation of China (Grant Nos. 11275131, 11305105, and 11271138) and Simons Foundation (Grant No. 198129).

Abstract

We consider the geometric global quantum discord (GGQD) of two-qubit systems. By analyzing the symmetry of geometric global quantum discord we give an approach for deriving analytical formulae of the extremum problem which lies at the core of computing the GGQD for arbitrary two-qubit states. Furthermore, formulae of GGQD of arbitrary two-qubit states and some concrete examples are presented.