Chains of Quasi-Classical Informations for Bipartite Correlations and the Role of Twin Observables

Abstract

Having the quantum correlations in a general bipartite state in mind, the information accessible by simultaneous measurement on both subsystems is shown never to exceed the information accessible by measurement on one subsystem, which, in turn is proved not to exceed the von Neumann mutual information. A particular pair of (opposite- subsystem) observables are shown to be responsible both for the amount of quasi-classical correlations and for that of the purely quantum entanglement in the pure-state case: the former via simultaneous subsystem measurements, and the latter through the entropy of coherence or of incompatibility, which is defined for the general case. The observables at issue are so-called twin observables. A general definition of the latter is given in terms of their detailed properties.

7 pages, Latex2e, selected for the December 2002 issue of the Virtual Journal of Quantum Information

References in corpus (3)

• Introducing Quantum Discord
• Mixed-state twin observables
• Hermitian Schmidt Decomposition and Twin Observables of Bipartite Mixed States

Cited by in corpus (6)

• A quantum measure of coherence and incompatibility
• Interpreting quantum coherence through a quantum measurement process
• Complete "Born's rule" from "environment-assisted invariance" in terms of pure-state twin unitaries
• The role of coherence entropy of physical twin observables in entanglement
• A Review of Unitary Quantum Premeasurement Theory An Algebraic Study of Basic Kinds of Premeasurements
• On bipartite pure-state entanglement structure in terms of disentanglement