Electrically induced and detected N\'eel vector reversal in a collinear antiferromagnet

TL;DR

This paper demonstrates electrical detection and switching of the Neel vector in a collinear antiferromagnet, CuMnAs, using a second-order magnetotransport effect linked to broken inversion symmetry, advancing antiferromagnetic spintronics.

Contribution

It introduces a method to electrically detect and switch the Neel vector in a collinear antiferromagnet via a non-linear magnetotransport effect, expanding spintronic control in antiferromagnetic materials.

Findings

Electrical detection of Neel vector reversal achieved.

Reversible switching of antiferromagnetic states demonstrated.

Stable magnetic states maintained over 25 hours.

Abstract

Electrical detection of the 180 deg spin reversal, which is the basis of the operation of ferromagnetic memories, is among the outstanding challenges in the research of antiferromagnetic spintronics. Analogous effects to the ferromagnetic giant or tunneling magnetoresistance have not yet been realized in antiferromagnetic multilayers. Anomalous Hall effect (AHE), which has been recently employed for spin reversal detection in non-collinear antiferromagnets, is limited to materials that crystalize in ferromagnetic symmetry groups. Here we demonstrate electrical detection of the 180 deg N\'eel vector reversal in CuMnAs which comprises two collinear spin sublattices and belongs to an antiferromagnetic symmetry group with no net magnetic moment. We detect the spin reversal by measuring a second-order magnetotransport coefficient whose presence is allowed in systems with broken space inversion symmetry. The phenomenology of the non-linear transport effect we observe in CuMnAs is consistent with a microscopic scenario combining anisotropic magneto-resistance (AMR) with a transient tilt of the N\'eel vector due to a current-induced, staggered spin-orbit field. We use the same staggered spin-orbit field, but of a higher amplitude, for the electrical switching between reversed antiferromagnetic states which are stable and show no sign of decay over 25 hour probing times.