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 -