The recently discovered altermagnets, featured by the exotic correlation of magnetic exchange interaction and alternating crystal environments, have offered exciting cutting-edge opportunities for spintronics. Nevertheless, the altermagnetism of RuO2, one of the earliest-discovered altermagnets, is currently under intense debate. Here we try to resolve this controversy by demonstrating an altermagnetic spin-splitting magnetoresistance (SSMR) effect that is driven by a spin current associated with the giant nonrelativistic spin splitting of an altermagnet. Compared to the spin Hall magnetoresistance induced by a conventional relativistic spin current, the SSMR is characterized by unusual angular dependence with a phase-shift feature underpinned by the Neel-vector orientation and pronounced temperature dependence caused by its susceptibility to electron scattering. Through systematical investigations on the magnetoresistance of (101)-RuO2/Co bilayers, we disentangle a sizable SSMR and hence unveil a Neel vector along [001] direction. Our work not only demonstrates a simple electric avenue to probing the Neel vector of altermagnets, but also indicates long-range magnetic order in thin films of RuO2.
@article{arxiv.2412.18220,
title = {Spin-Splitting Magnetoresistance in Altermagnetic RuO2 Thin Films},
author = {Hongyu Chen and Zian Wang and Peixin Qin and Ziang Meng and Xiaorong Zhou and Xiaoning Wang and Li Liu and Guojian Zhao and Zhiyuan Duan and Tianli Zhang and Jinghua Liu and Dingfu Shao and Chengbao Jiang and Zhiqi Liu},
journal= {arXiv preprint arXiv:2412.18220},
year = {2025}
}
Comments
40 pages, 13 figures. In press at Advanced Materials