Off-equilibrium scaling behaviors across first-order transitions

TL;DR

This paper investigates off-equilibrium scaling behaviors at first-order phase transitions in 2D Potts models, revealing phenomena similar to the Kibble-Zurek mechanism under slow temperature changes and specific boundary conditions.

Contribution

It introduces general ansatzes for off-equilibrium scaling at FOTs and demonstrates their validity through numerical simulations in 2D Potts models with mixed boundary conditions.

Findings

Kibble-Zurek-like scaling occurs at FOTs with appropriate boundary conditions

Numerical results for q=10 and q=20 Potts models support the proposed scaling behaviors

Interface effects are crucial for observing off-equilibrium phenomena at FOTs

Abstract

We study off-equilibrium behaviors at first-order transitions (FOTs) driven by a time dependence of the temperature across the transition point Tc, such as the linear behavior T(t)/Tc = 1 - t/ts where ts is a time scale. In particular, we investigate the possibility of nontrivial off-equilibrium scaling behaviors in the regime of slow changes, corresponding to large ts, analogous to those arising at continuous transitions, which lead to the so-called Kibble-Zurek mechanism. We consider the 2D Potts models which provide an ideal theoretical laboratory to investigate issues related to FOTs driven by thermal fluctuations. We put forward general ansatzes for off-equilibrium scaling behaviors around the time t=0 corresponding to Tc. Then we present numerical results for the q=10 and q=20 Potts models. We show that phenomena analogous to the Kibble-Zurek off-equilibrium scaling emerge also at FOTs with relaxational dynamics, when appropriate boundary conditions are considered, such as mixed boundary conditions favoring different phases at the opposite sides of the system, which enforce an interface in the system.