Collinear $p$-wave magnetism and hidden orbital ferrimagnetism

TL;DR

This paper reveals that collinear magnets can exhibit unconventional odd-wave magnetism with broken inversion symmetry, challenging traditional classifications and introducing new models and signatures like the Edelstein effect.

Contribution

It demonstrates the existence of collinear odd-wave magnets with broken inversion symmetry and proposes minimal models and experimental signatures for these unconventional states.

Findings

Collinear odd-wave magnets can break inversion symmetry.

Magnetic field-induced Edelstein effect as a signature.

Minimal models combining AFM and loop current orders.

Abstract

In the absence of spin-orbit coupling, collinear magnets are classified as even-wave magnets, i.e., either ferro-, antiferro-, or altermagnets. It is based on the belief that collinear magnets always feature an inversion-symmetric band structure, which forbids odd-wave magnetism. Here, we show that collinear magnets, which break time reversal symmetry in the non-magnetic sector, can have an inversion symmetry broken band structure and lead to unconventional types of collinear magnets. Hence, collinear odd-wave magnets do exist, and we explain that a magnetic field-induced Edelstein effect is their unique signature. We propose minimal models based on the coexistence of AFM order with compensated loop current orders for all types of collinear magnets. Our work provides a new perspective on collinear magnets and the spin-space group classification.