Order parameter fluctuation effects on current-induced magnetization

TL;DR

This study uses Monte Carlo simulations to show that fluctuations of order parameters in a chiral quadrupole system significantly suppress current-induced magnetization, revealing complex temperature-dependent behaviors influenced by Fermi surface properties.

Contribution

It demonstrates the impact of order parameter fluctuations on magnetoelectric effects in a metallic system with chiral quadrupole order, highlighting the importance of fluctuations in current-induced magnetization.

Findings

Order parameter fluctuations strongly suppress magnetization response.

Temperature dependence of magnetization differs from that of the order parameter.

Fermi surface properties influence the fluctuation effects.

Abstract

We investigate the impact of order parameter fluctuations on magnetoelectric effects in metallic systems using classical Monte Carlo simulations. We focus on a a chiral quadrupole order in a distorted kagome lattice in a model incorporating conduction electrons and classical orbital moments. The ordered orbital moments break mirror symmetry and couple with the conduction electrons, leading to a current-induced magnetization driven by the quadrupole order. Our findings reveal that order parameter fluctuations significantly affect the current-induced magnetization, strongly suppressing the response over a broad temperature range below the transition temperature. Additionally, we analyze the influence of Fermi surface properties and associated matrix elements on this phenomenon. Our results highlight the crucial role of fluctuation effects, demonstrating a qualitatively distinct temperature dependence of the current-induced magnetization compared to that of the order parameter itself.