Altermagnetic anomalous Hall effect emerging from electronic correlations

TL;DR

This paper introduces a model demonstrating how electronic correlations in altermagnetic materials can induce an anomalous Hall effect, supported by simulations and mean field analysis, revealing new pathways for correlation-driven topological phenomena.

Contribution

The study presents a novel model showing that interactions in altermagnets can generate an anomalous Hall effect, expanding understanding of correlation-induced topological properties.

Findings

Finite temperature phase transition with AFM and Haldane order parameters

Emergence of finite anomalous Hall conductivity in correlated altermagnets

Support from Quantum Monte Carlo simulations and mean field analysis

Abstract

While altermagnetic materials are characterized by a vanishing net magnetic moment, their symmetry in principle allows for the existence of an anomalous Hall effect (AHE). Here we introduce a model with altermagnetism in which the emergence of an AHE is driven by interactions. This model is grounded in a modified Kane-Mele framework with antiferromagnetic (AFM) spin-spin correlations. Quantum Monte Carlo simulations show that the system undergoes a finite temperature phase transition governed by a primary AFM order parameter accompanied by a secondary one of Haldane type. The emergence of both orders turns the metallic state of the system, away from half-filling, to an altermagnet with a finite anomalous Hall conductivity. A mean field ansatz corroborates these results, which pave the way into the study of correlation induced altermagnets with finite Berry curvature.