Thermodynamics of Fateev's models in the Presence of External Fields

TL;DR

This paper analyzes the thermodynamic properties of Fateev's quantum field models under external fields, revealing how chemical potentials influence excitation spectra and lead to new gapless modes and energy scales.

Contribution

It introduces a detailed thermodynamic analysis of Fateev's models with external fields, including the effects of chemical potentials on excitation spectra and low-energy effective theories.

Findings

Chemical potentials induce a kink condensate altering the spectrum.

Additional gapless modes emerge for certain chemical potential combinations.

Multiple energy scales are identified in the modified models.

Abstract

We study the Thermodynamic Bethe Ansatz equations for a one-parameter quantum field theory recently introduced by V.A.Fateev. The presence of chemical potentials produces a kink condensate that modifies the excitation spectrum. For some combinations of the chemical potentials an additional gapless mode appears. Various energy scales emerge in the problem. An effective field theory, describing the low energy excitations, is also introduced.