Tuning a random field mechanism in a frustrated magnet

TL;DR

This study uses Monte Carlo simulations to explore how spinless impurities influence a frustrated magnet with a stripe phase, revealing a tunable random-field mechanism that affects phase stability and transitions.

Contribution

It introduces a novel method to control the phase diagram of a frustrated magnet by tuning impurity interactions to modulate random fields.

Findings

Impurities induce a random-field mechanism destroying stripe order.

Tuning impurity repulsion controls the strength of random fields.

Impurities affect the nature of phase transitions between magnetic phases.

Abstract

We study the influence of spinless impurities on a frustrated magnet featuring a spin-density wave (stripe) phase by means of Monte Carlo simulations. We demonstrate that the interplay between the impurities and an order parameter that breaks a real-space symmetry triggers the emergence of a random-field mechanism which destroys the stripe-ordered phase. Importantly, the strength of the emerging random fields can be tuned by the repulsion between the impurity atoms; they vanish for perfect anticorrelations between neighboring impurities. This provides a novel way of controlling the phase diagram of a many-particle system. In addition, we also investigate the effects of the impurities on the character of the phase transitions between the stripe-ordered, ferromagnetic, and paramagnetic phases.