Pokrovsky-Talapov Model at finite temperature: a renormalization-group analysis

TL;DR

This paper uses renormalization-group analysis to study how finite temperature affects the critical wavevector in the Pokrovsky-Talapov model, relevant for phase transitions in physical systems.

Contribution

It provides a novel RG-based calculation of the finite-temperature shift of the critical wavevector, extending understanding of the model's phase transition behavior.

Findings

Derived flow equations for stiffness and potential.

Compared results with the sine-Gordon model.

Applied findings to physical systems' phase transitions.

Abstract

We calculate the finite-temperature shift of the critical wavevector $Q_{c}$ of the Pokrovsky-Talapov model using a renormalization-group analysis. Separating the Hamiltonian into a part that is renormalized and one that is not, we obtain the flow equations for the stiffness and an arbitrary potential. We then specialize to the case of a cosine potential, and compare our results to well-known results for the sine-Gordon model, to which our model reduces in the limit of vanishing driving wavevector Q=0. Our results may be applied to describe the commensurate-incommensurate phase transition in several physical systems and allow for a more realistic comparison with experiments, which are always carried out at a finite temperature.