2025/02/14 by Yamada, Rinsuke, Birch, Max T., Baral, Priya R. +20 · 17 citations
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Other Condensed Matter (cond-mat.other) #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2502.10386
Antiferromagnetic states with spin-split electronic structure give rise to novel spintronic, magnonic, and electronic phenomena despite (near-) zero net magnetization. The simplest odd-parity spin splitting - p-wave - was originally proposed to emerge from a collective instability in interacting electron systems. Recent theory identifies a distinct route to realise p-wave spin-split electronic bands without strong correlations, termed p-wave magnetism. Here we demonstrate an experimental realisation of a metallic p-wave magnet. The odd-parity spin splitting of delocalised conduction electrons arises from their coupling to an antiferromagnetic texture of localised magnetic moments: a coplanar spin helix whose magnetic period is an even multiple of the chemical unit cell, as revealed by X-ray scattering experiments. This texture breaks space inversion symmetry but preserves time-reversal (T) symmetry up to a half-unit-cell translation - thereby fulfilling the symmetry conditions for p-wave magnetism. Consistent with theoretical predictions, our p-wave magnet exhibits a characteristic anisotropy in the electronic conductivity. Relativistic spin-orbit coupling and a tiny spontaneous net magnetization further break T symmetry, resulting in a giant anomalous Hall effect (AHE, σxy>600 S/cm, Hall angle >3 %), for an antiferromagnet. Our model calculations show that the spin nodal planes found in the electronic structure of p-wave magnets are readily gapped by a small perturbation to induce the AHE.