Instantons and Surface Tension at a First-Order Transition

TL;DR

This paper investigates the dynamics of first-order phase transitions in the 2D 15-state Potts model, demonstrating nucleation processes, instanton-based surface tension measurement, and the significance of fluctuation effects.

Contribution

It introduces an instanton-based method to measure surface tension during phase transitions and analyzes fluctuation effects in the 2D Potts model.

Findings

Phase changes occur via nucleation in the model.

Surface tension measurements align with perfect wetting.

Fluctuations around instantons are crucial for accurate analysis.

Abstract

We study the dynamics of the first order phase transition in the two dimensional 15-state Potts model, both at and off equilibrium. We find that phase changes take place through nucleation in both cases, and finite volume effects are described well through an instanton computation. Thus a dynamical measurement of the surface tension is possible. We find that the order-disorder surface tension is compatible with perfect wetting. An accurate treatment of fluctuations about the instanton solution is seen to be of great importance.