We define a new measure of quantum correlations in bipartite quantum systems given by the Bures distance of the system state to the set of classical states with respect to one subsystem, that is, to the states with zero quantum discord. Our measure is a geometrical version of the quantum discord. As the latter it quantifies the degree of non-classicality in the system. For pure states it is ide...

In this work, we study quantum correlations in mixed states. The states studied are modeled by a two-qubit system interacting with its environment via a quantum nondemolition (purely dephasing) as well as dissipative type of interaction. The entanglement dynamics of this two qubit system is analyzed and the existence of entangled states which do not violate Bell’s inequality, but can still be u...