Nonlinear nonreciprocal transport in antiferromagnets free from spin-orbit coupling

TL;DR

This paper proposes a theoretical mechanism for nonlinear nonreciprocal transport in antiferromagnets that does not depend on spin-orbit coupling, highlighting new ways to engineer parity-violating transport phenomena.

Contribution

It introduces a novel theoretical framework showing how local spin scalar chirality and electric polarization induce nonlinear transport without spin-orbit coupling.

Findings

Demonstrates nonlinear transport in antiferromagnets with specific magnetic orderings

Identifies symmetry conditions for asymmetric band modulation and Berry-curvature effects

Provides examples with triangular and kagome lattices under magnetic fields

Abstract

We theoretically propose a realization of a nonlinear nonreciprocal transport in antiferromagnets without relying on the relativistic spin-orbit coupling. Through the symmetry and microscopic model analyses, we show that a local spin scalar chirality to induce an asymmetric band modulation becomes a source of a Drude-type nonlinear transport, while an electric polarization induced by a collinear spin configuration in a triangle unit leads to a Berry-curvature-dipole-type nonlinear transport. We demonstrate that 120$^\circ$ antiferromagnetic ordering on a triangular lattice and a breathing kagome lattice in an external magnetic field are typical examples. Our results open a new direction of designing and engineering functional materials with showing rich parity-violating transport phenomena by spontaneous magnetic phase transitions.