Introduces a universal correlation index for measuring quantum and classical correlations in equilibrium and nonequilibrium statistical systems, including entanglement in multipartite quantum states.

Introduces a universal correlation index for measuring quantum and classical correlations in equilibrium and nonequilibrium statistical systems, including entanglement in multipartite quantum states.
Derives exact analytical expressions for correlation patterns in cyclic fermionic systems using symmetry principles, revealing interference-induced selection rules for mutual information at specific distances in mean-field states.
A novel method of correlation indices quantifies all types of correlations—quantum and classical, static and dynamic—in composite systems uniformly. Demonstrated for entanglement, Bell states, and Bose-Einstein condensates.