Multicritical Behavior in a Random-Field Ising Model under a Continuous-Field Probability Distribution

TL;DR

This paper investigates a complex random-field Ising model with a triple-Gaussian distribution, revealing rich multicritical phenomena and phase behavior, including smearing effects, in an infinite-range interaction setting.

Contribution

It introduces a generalized triple-Gaussian random magnetic field distribution in the Ising model, unifying various known distributions and exploring their multicritical behaviors.

Findings

Identification of multicritical points and phase transitions.

Demonstration of smearing effects in phase behavior.

Unification of trimodal, bimodal, and Gaussian distributions as special cases.

Abstract

A random-field Ising model that is capable of exhibiting a rich variety of multicritical phenomena, as well as a smearing of such behavior, is investigated. The model consists of an infinite-range-interaction Ising ferromagnet in the presence of a triple-Gaussian random magnetic field, which is defined as a superposition of three Gaussian distributions with the same width $\sigma$, centered at H=0 and $H=\pm H_{0}$, with probabilities $p$ and $(1-p)/2$, respectively. Such a distribution is very general and recovers as limiting cases, the trimodal, bimodal, and Gaussian probability distributions.