- Editors' Suggestion
- Letter
Odd-parity altermagnetism: A spin group study
Phys. Rev. B 113, L220412 – Published 24 June, 2026
DOI: https://doi.org/10.1103/7kmk-yl2t
Abstract
Following recent intensive studies on altermagnetism (ALM) characterized by nonrelativistic even-parity spin splitting, realizing unconventional odd-parity magnetism has also attracted increasing interest. Here, using symmetry arguments based on spin-group analyses, we elucidate necessary conditions for the emergence of odd-parity spin splitting in collinear antiferromagnetic systems, which is further established as the standard odd-parity ALM. It is derived that the odd-parity ALM arises from the following criteria: (i) the breaking nonmagnetic time reversal symmetry (TRS), i.e., the breaking real-space TRS; (ii) the long-range collinear compensated magnetism; (iii) the symmetry or connecting opposite-spin sublattices, where , and , respectively, represent a rotation around the axis perpendicular to spins, the inversion, and the mirror reflection separating opposite-spin sublattices, directly reflecting the high-order harmonic () and the -wave () odd-parity ALM, respectively. Moreover, we utilize the well-known Haldane-Hubbard model to identify odd-parity spin splitting in the collinear ALM ground state, where (i) the nonmagnetic TRS is broken by opposite sublattice currents coming from the Haldane hopping; (ii) the symmetry is ensured because the currents flowing on opposite-spin sublattices are reversed.