Conditional purity and quantum correlation measures in two qubit mixed states

L REBÓN; R. ROSSIGNOLI; J. J. M. VARGA; N. GIGENA; N. CANOSA; C. IEMMI; S. LEDESMA

JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2016 vol. 49

0953-4075

We analyze and show experimental results of the conditional purity, the quantum discord and other related measures of quantum correlation in mixed two-qubit states constructed from a pair of photons in identical polarization states. The considered states are relevant for the description of spin pair states in interacting spin chains in a transverse magnetic field. We derive clean analytical expressions for the conditional local purity and other correlation measures obtained as a result of a remote local projective measurement, which are fully verified by the experimental results. A simple exact expression for the quantum discord of these states in terms of the maximum conditional purity is also derive