Two-Terminal Electrical Detection of the N\'eel Vector via Longitudinal Antiferromagnetic Nonreciprocal Transport

TL;DR

This paper introduces a universal two-terminal electrical method to detect the Néel vector in antiferromagnets using longitudinal nonreciprocal transport driven by quantum metric dipoles, avoiding complex device architectures.

Contribution

It presents a novel, scalable electrical readout scheme for AFM spin states based on quantum metric dipoles, applicable to various materials without specialized electrodes.

Findings

Demonstrated sign reversal of LNC in MnS and CuMnAs with Néel vector reorientation

Showed LNC is mainly governed by intrinsic quantum metric mechanism

Provided a practical method for electrical detection of AFM memory states

Abstract

We propose a robust two-terminal electrical readout scheme for detecting the N\'eel vector orientation in antiferromagnetic (AFM) materials by leveraging longitudinal nonreciprocal transport driven by quantum metric dipoles. Unlike conventional readout mechanisms, our approach does not require spin-polarized electrodes, tunneling junctions, or multi-terminal geometries, offering a universal and scalable solution for AFM spintronics. As examples, we demonstrate pronounced second-order longitudinal nonlinear conductivity (LNC) in two-dimensional (2D) MnS and 3D CuMnAs, both of which exhibit clear sign reversal of LNC under 180$^\circ$ N\'eel vector reorientation. We show that this LNC is predominantly governed by the intrinsic, relaxation-time-independent quantum metric mechanism rather than the extrinsic nonlinear Drude effect. Our findings provide a practical and material-general pathway for electrically reading AFM memory states, with promising implications for next-generation AFM spintronic technologies.