Intrinsic nonlinear Hall effect in antiferromagnetic tetragonal CuMnAs

TL;DR

This paper investigates the intrinsic nonlinear Hall effect in antiferromagnetic CuMnAs, highlighting its potential for detecting Néel vector orientation and providing a comprehensive symmetry analysis for identifying similar materials.

Contribution

It identifies the intrinsic nonlinear Hall effect as a relaxation-time-independent probe for antiferromagnetic order and offers a symmetry-based guide for discovering related materials.

Findings

Nonlinear Hall conductivity in CuMnAs can reach mA/V^2

The effect depends strongly on temperature and chemical potential

A symmetry analysis guides the search for similar materials

Abstract

Detecting the orientation of the N\'eel vector is a major research topic in antiferromagnetic spintronics. Here we recognize the intrinsic nonlinear Hall effect, which is independent of the relaxation time, as a prominent contribution to the time-reversal-odd second order conductivity and can be used to detect the flipping of the N\'eel vector. In contrast, the Berry-curvature-dipole-induced nonlinear Hall effect depends linear on relaxation time and is time-reversal-even. We study the intrinsic nonlinear Hall effect in an antiferromagnetic metal: tetragonal CuMnAs, and show that its nonlinear Hall conductivity can reach the order of mA/V$^2$. The dependence on the chemical potential of such nonlinear Hall conductivity can be qualitatively explained by a tilted massive Dirac model. Moreover, we demonstrate its strong temperature dependence and briefly discuss its competition with the second order Drude conductivity. Finally, a complete survey of magnetic point groups are presented, providing guidelines for finding more antiferromagnetic materials with the intrinsic nonlinear Hall effect.