Absence of Altermagnetic Spin Splitting Character in Rutile Oxide RuO 2

作者：Jiayu Liu, Jie Zhan, Tongrui Li, Jishan Liu, Shufan Cheng, Yuming Shi, Liwei Deng, Meng Zhang, Chihao Li, Jianyang Ding, Qi Jiang, Mao Ye, Zhengtai Liu, Zhicheng Jiang, Siyu Wang, Qian Li, Yanwu Xie, Yilin Wang, Shan Qiao, Jinsheng Wen, Yan Sun, Dawei Shen · 发表于：Physical Review Letters · 年份：2024 · DOI：10.1103/physrevlett.133.176401 · 被引用次数：148 · 研究领域：Advanced Condensed Matter Physics、Multiferroics and related materials、Magnetic and transport properties of perovskites and related materials

Rutile RuO_{2} has been posited as a potential d-wave altermagnetism candidate, with a predicted significant spin splitting up to 1.4 eV. Despite accumulating theoretical predictions and transport measurements, direct spectroscopic observation of spin splitting has remained elusive. Here, we employ spin- and angle-resolved photoemission spectroscopy to investigate the band structures and spin polarization of thin-film and single-crystal RuO_{2}. Contrary to expectations of altermagnetism, our analysis indicates that RuO_{2}'s electronic structure aligns with those predicted under nonmagnetic conditions, exhibiting no evidence of the hypothesized spin splitting. Additionally, we observe significant in-plane spin polarization of the low-lying bulk bands, which is antisymmetric about the high-symmetry plane and contrary to the d-wave spin texture due to time-reversal symmetry breaking in altermagnetism. These findings definitively challenge the altermagnetic order previously proposed for rutile RuO_{2}, prompting a reevaluation of its magnetic properties.