$\lambda$-Type phase transition for a weakly interacting bose gas

TL;DR

This paper explains the origin of the lambda-shaped specific heat transition in a weakly interacting Bose gas, demonstrating a general mechanism applicable to various quasiparticle spectra, including Bogoliubov's model.

Contribution

It introduces a new mechanism for the lambda transition in Bose gases, applicable to a broad class of quasiparticle spectra, with specific analysis for Bogoliubov's model.

Findings

Identifies a general mechanism for lambda-type specific heat behavior.

Applies the mechanism to Bogoliubov's model of a weakly interacting Bose gas.

Shows the spectrum's temperature dependence is key to the transition.

Abstract

A mechanism generating a $\lambda$-type behavior in the specific heat of a Bose gas near the critical temperature $T_c$ is discussed. It is shown to work for a general class of quasiparticle spectra, and especially, for the Bogoliubov's model of a weakly interacting Bose gas, where a temperature-dependent quasi-particle spectrum is obtained.