Phase Transition in Interacting Boson System at Finite Temperatures

TL;DR

This paper investigates phase transitions in an interacting boson system at finite temperatures using a mean-field model, revealing a first-order phase transition with a constant density in the condensed phase and a density jump at the critical temperature.

Contribution

It introduces a Skyrme-like mean-field model with both attractive and repulsive terms to study phase transitions in boson systems at finite temperatures.

Findings

First-order phase transition occurs with strong attractive interactions.

Condensed phase has a constant total particle density.

Energy density shows a jump at the critical temperature.

Abstract

Thermodynamical properties of an interacting boson system at finite temperatures and zero chemical potential are studied within the framework of the Skyrme-like mean-field toy model. It is assumed that the mean field contains both attractive and repulsive terms. Self-consistency relations between the mean field and thermodynamic functions are derived. It is shown that for sufficiently strong attractive interactions this system develops a first-order phase transition via formation of Bose condensate. An interesting prediction of the model is that the condensed phase is characterized by a constant total density of particles. The thermodynamical characteristics of the system are calculated for the liquid-gas and condensed phases. The energy density exhibits a jump at the critical temperature.