Siyu Wang, Chao Wang, Yanan Yuan, Jiangxiao Li, Fangfang Pei, Daxiang Liu, Chunyu Qin, Jiefeng Cao, Yamei Wang, Tianye Wang, Jiayu Liu, Ji-Eun Lee, Guanhua Zhang, Christoph Klewe, Chenchao Yu, Fan Zhang, Dongsheng Song, Kai Chen, Weisheng Zhao, Dawei Shen, Ziqiang Qiu, Mengmeng Yang, Bin Hong, and Qian Li
Phys. Rev. B 113, 024439 (2026) - Published 30 January, 2026
Ruthenium dioxide (RuO), a top altermagnetic candidate, has undergone some dispute regarding the existence of magnetic order. Here, the authors directly probe its magnetic state using x-ray linear dichroism (XLD) measurements on high-quality epitaxial thin films. By comparing data across temperatures, field-cooling, and crystalline orientations, they found no evidence of intrinsic magnetic ordering. As XLD signals can originate from both magnetic and crystal field contributions, the authors emphasize the critical need to disentangle genuine magnetism from nonmagnetic effects in complex materials.