Wigner Function Analysis of Finite Matter-Radiation Systems

TL;DR

This paper demonstrates that analyzing the Wigner function in phase space reveals entanglement and quantum phase transitions in matter-radiation systems, providing a detailed classification of phase transitions.

Contribution

It introduces a method to extract entanglement and phase transition information from the Wigner function in finite matter-radiation systems.

Findings

Wigner function behavior indicates entanglement properties.

Phase space analysis reveals quantum phase transition regions.

Minimum fidelity surface helps classify continuous phase transitions.

Abstract

We show that the behaviour in phase space of the Wigner function associated to the electromagnetic modes carries the information of both, the entanglement properties between matter and field, and the regions in parameter space where quantum phase transitions take place. A finer classification for the continuous phase transitions is obtained through the computation of the surface of minimum fidelity.