arXiv:1010.1920 [quant-ph]AbstractReferencesReviewsResources
Tight lower bound to the geometric measure of quantum discord
Ali Saif M. Hassan, Behzad Lari, Pramod S. Joag
Published 2010-10-10, updated 2012-01-30Version 3
Dakic, Vedral and Brukner [Physical Review Letters \tf{105},190502 (2010)] gave a geometric measure of quantum discord in a bipartite quantum state as the distance of the state from the closest classical quantum (or zero discord) state and derived an explicit formula for a two qubit state. Further, S.Luo and S.Fu [Physical Review A \tf{82}, 034302 (2010)] obtained a generic form of this geometric measure for a general bipartite state and established a lower bound. In this brief report we obtain a rigorous lower bound to the geometric measure of quantum discord in a general bipartite state which dominates that obtained by S.Luo and S.Fu.