Two-Terminal Electrical Detection of the Néel Vector via Longitudinal Antiferromagnetic Nonreciprocal Transport.

Efficient electrical detection of the Néel vector is a key requirement for the development of antiferromagnetic (AFM) spintronic devices. Longitudinal nonlinear transport provides a universal and scalable approach for two-terminal electrical readout of the Néel vector orientation. However, the current set of candidate AFM materials exhibiting this effect remains rather limited. In this work, via first-principles calculations, we reveal significant second-order longitudinal nonlinear conductivity (LNC) in a range of AFM systems and present a detailed symmetry analysis. Taking two-dimensional (2D) MnS and three-dimensional CuMnAs as examples, we show that both materials display a distinct sign reversal of the LNC under 180° Néel vector reorientation. Furthermore, the LNC of these materials is substantially enhanced near the nearly degenerate points of their energy bands. Our results broaden the range of nonlinear transport effects in AFM systems, holding promising potential for next-generation AFM spintronic technologies.