Effective field theory for He-IV

TL;DR

This paper proposes an effective scalar field theory based on a Ginzburg-Landau Hamiltonian with higher derivatives to model the phase diagram of He-IV, capturing superfluid, normal liquid, and solid phases.

Contribution

It introduces a novel theoretical model extending the XY model to better describe He-IV phase transitions using higher-order derivatives.

Findings

Model reproduces qualitative features of He-IV phase transitions

Mean field and Monte Carlo analyses support the model's validity

Captures transitions between superfluid, normal liquid, and solid phases

Abstract

We introduce an effective scalar field theory to describe the He-IV phase diagram, which can be considered as a generalization of the XY model which gives the usual lambda-transition. This theory results from a Ginzburg-Landau Hamiltonian with higher order derivatives, which allow to produce transitions between the superfluid, normal liquid and solid phases of He-IV. Mean field and Monte Carlo analyses suggest that this model is able to reproduce the main qualitative features of He-IV phase transitions.