Relativistic Néel-Order Fields Induced by Electrical Current in Antiferromagnets

TLDR

We predict that a lateral electrical current in antiferromagnets induces staggered Néel‑order fields and propose an AFM memory device with electrical writing and reading. Microscopic transport theory shows these fields arise from intra‑band and inter‑band spin‑orbit mechanisms analogous to those in ferromagnets, and we illustrate this in bulk Mn₂Au and a Rashba‑coupled 2D square‑lattice antiferromagnet. The staggered fields can trigger ultra‑fast spin‑axis reorientation.

Abstract

We predict that a lateral electrical current in antiferromagnets can induce non-equilibrium N\'eel order fields, i.e. fields whose sign alternates between the spin sublattices, which can trigger ultra-fast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced fields analogous to the intra-band and to the intrinsic inter-band spin-orbit fields previously reported in ferromagnets with a broken inversion-symmetry crystal. To illustrate their rich physics and utility, we considered bulk Mn2Au with the two spin sublattices forming inversion partners, and a 2D square-lattice antiferromagnet with broken structural inversion symmetry modelled by a Rashba spin-orbit coupling. We propose an AFM memory device with electrical writing and reading.