Measuring geometric quantum discord using one bit of quantum information

Geometric measure of quantum discord under decoherence

The dynamics of a geometric measure of the quantum discord (GMQD) under decoherence is investigated. We show that the GMQD of a two-qubit state can be alternatively obtained through the singular values of a 3×4 matrix whose elements are the expectation values of Pauli matrices of the two qubits. By using Heisenberg picture, the analytic results of the GMQD is obtained for three typical kinds of...

Power of One Bit of Quantum Information in Quantum Metrology

Geometric quantum discord with Bures distance

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...

Measuring quantum discord using the most distinguishable steered states

Any two-qubit state can be represented, geometrically, as an ellipsoid with a certain size and center located within the Bloch sphere of one of the qubits. Points of this ellipsoid represent the postmeasurement states when the other qubit is measured. Based on the most demolition concept in the definition of quantum discord, we study the amount of demolition when the two post-measurement states...

The one-way unlocalizable quantum discord

In this paper, we present the concept of the one-way unlocalizable quantum discord and investigate its properties. We provide a polygamy inequality for it in tripartite pure quantum system of arbitrary dimension. Several tradeoff relations between the one-way unlocalizable quantum discord and other correlations are given. If the von Neumann measurement is on a part of the system, we give two ex...