Topological properties of magnetically ordered heavy-fermion systems in the presence of mirror symmetry

TL;DR

This paper investigates how mirror symmetry enables topological phases in magnetically ordered heavy-fermion systems, revealing new topological states and half-metallic phases influenced by spin-orbit coupling.

Contribution

It demonstrates the emergence of topological phases in 2D heavy-fermion systems with magnetic order due to mirror symmetry, even with spin nonconservation.

Findings

Topological phases appear in 2D antiferromagnetic systems with mirror symmetry.

A half-metallic state with a spin-selective gap emerges in ferromagnetic phases.

The scenario applies to systems with spin-orbit coupling, unlike previous models.

Abstract

We explore topological states with magnetic order in heavy-fermion systems by taking account of a mirror symmetry.Although without spatial symmetry, there is no topological phase in the two-dimensional (2D) antiferromagnetic phases at half filling, we demonstrate that a topological phase emerges in the presence of mirror symmetry.This is explicitly shown for a two-dimensional periodic Anderson model.Furthermore, our analysis around quarter filling shows that a half-metallic state emerges in the ferromagnetic phase, where a spin-selective gap opens, resulting in nontrivial properties characterized by a Chern number.In contrast to the previously proposed models, our scenario can apply even for spin nonconserving systems in the presence of spin-orbit coupling.