Non-commutativity measure of quantum discord

Yu Guo
2016 Scientific Reports  
Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord. two measures: the trace norm measure and
more » ... he Hilbert-Schmidt norm one. Both of them can be calculated for any state directly via the Lie product of the local operators. We then analyze our quantities for the Werner state, the isotropic state and the Bell-diagonal state in which the original quantum discord have been calculated. By comparing our quantities with the original one, we find that our quantities can quantify quantum discord roughly for these states.
doi:10.1038/srep25241 pmid:27122226 pmcid:PMC4848517 fatcat:hmf3ufdxfrhebba5ddo3ahzopm