Persistence of large and gate-tunable anisotropic magnetoresistance in an atomically thin antiferromagnet

TL;DR

This study demonstrates that ultrathin semiconducting van der Waals antiferromagnets can exhibit gate-tunable anisotropic magnetoresistance, enabling electrical readout of magnetic states at atomic thicknesses for advanced spintronic applications.

Contribution

We show electrical detection of the Néel vector in 2D NiPS3 down to two layers, with gate-tunable AMR contributions and full control over magnetoresistance sign and magnitude.

Findings

AMR persists in 1.3 nm NiPS3 (two layers).

Gate voltage controls AMR magnitude and sign.

Two distinct AMR contributions dominate at different charge densities.

Abstract

Anisotropic magnetoresistance (AMR) offers a robust electrical readout of antiferromagnetic (AFM) states, playing a central role in the rapidly advancing field of AFM spintronics. Despite its great versatility, electrical probing of the N\'eel vector via AMR remains challenging in the ultrathin limit due to interface disorder and reduced dimensionality. Here, we demonstrate electrical readout of the N\'eel vector down to 1.3 nm (two layers) in the two-dimensional van der Waals (vdW) AFM semiconductor NiPS3. Leveraging spin-flop-mediated rotation of the N\'eel vector and using both transistor and tunnel-junction device geometries, we identify two distinct AMR contributions in NiPS3, that dominate at low and high charge densities, respectively. We achieve full gate control over these contributions, enabling tunability of both the magnitude and sign of magnetoresistance. Our results establish semiconducting vdW antiferromagnets as a rich platform for studying AMR in the ultrathin limit, opening new avenues for multifunctional AFM spintronic devices.