Multicriticality in the Blume-Capel model under a continuous-field probability distribution

TL;DR

This paper explores how quenched disorder in the crystal field affects the multicritical behavior of the infinite-range Blume-Capel model, revealing complex phase diagrams and the suppression of tricritical points.

Contribution

It introduces a novel disorder distribution in the crystal field and analyzes its impact on the phase diagram topology and multicritical phenomena.

Findings

Rich variety of phase diagram topologies identified

Disorder reduces the complexity of phase diagrams

Fourth-order critical points analyzed

Abstract

The multicritical behavior of the Blume-Capel model with infinite-range interactions is investigated by introducing quenched disorder in the crystal field $\Delta_{i}$, which is represented by a superposition of two Gaussian distributions with the same width $\sigma$, centered at $\Delta_{i} = \Delta$ and $\Delta_{i} = 0$, with probabilities $p$ and $(1-p)$, respectively. A rich variety of phase diagrams is presented, and their distinct topologies are shown for different values of $\sigma$ and $p$. The tricritical behavior is analyzed through the existence of fourth-order critical points as well as how the complexity of the phase diagrams is reduced by the strength of the disorder.