TY - JOUR

T1 - Unified view of correlations using the square-norm distance

AU - Bellomo, Bruno

AU - Lo Franco, Rosario

AU - Compagno, Giuseppe

AU - Galve, Fernando

AU - Zambrini, Roberta

AU - Giorgi, Gian Luca

AU - Lo Franco, Rosario

PY - 2012

Y1 - 2012

N2 - The distance between a quantum state and its closest state not having a certain property has been used to quantify the amount of correlations corresponding to that property. This approach allows a unified view of the various kinds of correlations present in a quantum system. In particular, using relative entropy as a distance measure, total correlations can be meaningfully separated into a quantum part and a classical part thanks to an additive relation involving only the distances between states. Here we investigate a unified view of correlations using as a distance measure the square norm, which has already been used to define the so-called geometric quantum discord. We thus also consider geometric quantifiers for total and classical correlations, finding, for a quite general class of bipartite states, their explicit expressions. We analyze the relationship among geometric total, quantum, and classical correlations, and we find that they no longer satisfy a closed additivity relation.

AB - The distance between a quantum state and its closest state not having a certain property has been used to quantify the amount of correlations corresponding to that property. This approach allows a unified view of the various kinds of correlations present in a quantum system. In particular, using relative entropy as a distance measure, total correlations can be meaningfully separated into a quantum part and a classical part thanks to an additive relation involving only the distances between states. Here we investigate a unified view of correlations using as a distance measure the square norm, which has already been used to define the so-called geometric quantum discord. We thus also consider geometric quantifiers for total and classical correlations, finding, for a quite general class of bipartite states, their explicit expressions. We analyze the relationship among geometric total, quantum, and classical correlations, and we find that they no longer satisfy a closed additivity relation.

KW - Entanglement

KW - Quantum correlations

KW - Entanglement

KW - Quantum correlations

UR - http://hdl.handle.net/10447/66624

UR - http://pra.aps.org/abstract/PRA/v85/i3/e032104

M3 - Article

SN - 1050-2947

VL - 85

SP - 032104-1-032104-9

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

ER -