Reentrant Behavior of the Spinodal Curve in a Nonequilibrium Ferromagnet

TL;DR

This paper investigates the reentrant behavior of the spinodal curve in a nonequilibrium ferromagnetic system, revealing that metastability appears only at intermediate temperatures due to complex thermal and nonequilibrium fluctuations.

Contribution

It demonstrates the reentrant spinodal behavior in a nonequilibrium ferromagnet using simulations and mean-field analysis, highlighting the role of multiplicative noise.

Findings

Reentrant spinodal curve as a function of temperature under strong nonequilibrium conditions

Metastability occurs only at intermediate temperatures, not at low or high

Nonlinear interplay between thermal and nonequilibrium fluctuations causes this behavior

Abstract

The metastable behavior of a kinetic Ising--like ferromagnetic model system in which a generic type of microscopic disorder induces nonequilibrium steady states is studied by computer simulation and a mean--field approach. We pay attention, in particular, to the spinodal curve or intrinsic coercive field that separates the metastable region from the unstable one. We find that, under strong nonequilibrium conditions, this exhibits reentrant behavior as a function of temperature. That is, metastability does not happen in this regime for both low and high temperatures, but instead emerges for intermediate temperature, as a consequence of the non-linear interplay between thermal and nonequilibrium fluctuations. We argue that this behavior, which is in contrast with equilibrium phenomenology and could occur in actual impure specimens, might be related to the presence of an effective multiplicative noise in the system.