2026/07/20 by Zheng-Yang Zhuang, Zhongbo Yan
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.mtrl-sci #cond-mat.str-el
5+1 pages, 4 figures; Two sections added in End Matter
arxiv created 2026/07/30 · arxiv updated 2026/07/31
Altermagnetism combines compensated magnetic order with nonrelativistic spin splitting, yet established mechanisms predominantly rely on spin-reversing rotations in Néel-order antiferromagnets. Here we establish stripe-order altermagnetism governed instead by a spin-reversing mirror, placing it outside the usual rotation-based l-wave classification. Using two-orbital models, we show that the interplay between stripe spin and orbital orders can yield a stripe altermagnet with mirror-constrained nematic spin splitting or a stripe anti-altermagnet with spin-degenerate bands. The latter can support ferroelectric-like electrical control of spin splitting in suitable buckled structures. Random-phase-approximation (RPA) calculations show that stripe-order altermagnetism is favored near half filling under strong hopping anisotropy. The spin-reversing mirror further enforces a purely transverse Drude spin current for an electric field parallel or normal to the mirror plane, while spin-resolved mirror and rotation probes distinguish this response from that of rotation-governed l-wave altermagnets.