Asymmetry of bipartite quantum discord
E. B. Fel'dman, A. I. Zenchuk
Institute of Problems of Chemical Physics RAS, 142432 Chernogolovka, Moscow reg., Russia
Abstract
It is known from the analysis of the density matrix for bipartite systems that the quantum discord (as a measure of quantum correlations) depends on the particular subsystem chosen for the projective measurements.
We study asymmetry of the discord in a simple physical model of two spin-1/2 particles with the dipole-dipole interaction governed by the XY Hamiltonian in the inhomogeneous magnetic field.
The dependence of the above discord asymmetry on the Larmour frequencies at both T=0 (the ground state) and T>0 has been investigated.
It is demonstrated, in particular, that the asymmetry is negligible for high temperatures but it may become significant with the decrease in temperature.