Covariance, correlation and entanglement
Quantum Physics
2009-11-06 v1
Abstract
Some new identities for quantum variance and covariance involving commutators are presented, in which the density matrix and the operators are treated symmetrically. A measure of entanglement is proposed for bipartite systems, based on covariance. This works for two- and three-component systems but produces ambiguities for multicomponent systems of composite dimension. Its relationship to angular momentum dispersion for symmetric symmetric spin states is described.
Cite
@article{arxiv.quant-ph/0001076,
title = {Covariance, correlation and entanglement},
author = {R I A Davis and R Delbourgo and P D Jarvis},
journal= {arXiv preprint arXiv:quant-ph/0001076},
year = {2009}
}
Comments
30 pages, Latex, to appear in J Phys A