Specificity of Phase Transition of Quasi-Spin System in Two-Quantum Exchange with Thermostat

TL;DR

This paper investigates how two-photon exchange interactions in a quasi-spin system influence quantum phase transitions, revealing that temperature increases the atom-field exchange integral and critical temperature, altering the phase transition characteristics.

Contribution

It demonstrates that two-photon exchange interactions cause the atom-field exchange integral and critical temperature to increase with temperature, affecting the phase transition behavior.

Findings

Atom-field exchange integral increases with temperature.

Critical temperature is higher than in traditional second-order transitions.

Nonlinear exchange leads to unique phase transition features.

Abstract

The quantum phase transition of the system of N radiators in case of two-photon exchange interaction with cavity electromagnetic field is considered. It is shown that for this system the atom-field exchange integral increases with the increase of temperature. This effect generates peculiarities in phase transition picture. The process of nonlinear exchange between the quasi-spins leads to the increase of critical temperature as compared to traditional second order phase transition of quasi-spin system.