Stable, metastable and unstable states in the mean-field RFIM at T=0

TL;DR

This paper analyzes the mean-field RFIM at zero temperature, revealing that metastable states exist with finite probability even on unstable branches, affecting how the system's states are accessed.

Contribution

It demonstrates that metastable states are present with finite probability on unstable branches in the mean-field RFIM at T=0, challenging previous assumptions.

Findings

Metastable states have finite probability on unstable branches.

Unstable branches are accessible when magnetization is controlled.

Implications for the understanding of state accessibility in RFIM.

Abstract

We compute the probability of finding metastable states at a given field in the mean-field random field Ising model at T=0. Remarkably, this probability is finite in the thermodynamic limit, even on the so-called ``unstable'' branch of the magnetization curve. This implies that the branch is reachable when the magnetization is controlled instead of the magnetic field, in contrast with the situation in the pure system.