Lu Wenlong, Feng Shiyu, Wang Yuzhi, Chen Dong, Lin Zihan, Liang Xin, Liu Siyuan, Feng Wanxiang, Yamagami Kohei, Liu Junwei, Felser Claudia, Wu Quansheng, Ma Junzhang
Department of Physics, City University of Hong Kong, Kowloon, Hong Kong, China.
Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
Nano Lett. 2025 May 7;25(18):7343-7350. doi: 10.1021/acs.nanolett.5c00482. Epub 2025 Apr 28.
As a special type of collinear antiferromagnetism (AFM), altermagnetism has garnered significant research interest recently. Altermagnets exhibit broken parity-time symmetry and zero net magnetization, leading to substantial band splitting in the momentum space. Meanwhile, parity-time symmetry breaking is a prerequisite for nontrivial band topology in Weyl physics. When there is band crossing, it is usually easy to generate Weyl nodes. Weyl semimetal states have been theoretically proposed in altermagnets; rare reports of experimental observation have been made up to this point. Using angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations, we systematically studied the electronic structure of room-temperature altermagnet candidate CrSb. We clearly observed the band spin splitting and signature of topological surface states on the (100) cleaved side surface close to the Fermi level originating from bulk band topology. Our results imply that CrSb contains interesting nontrivial topological Weyl physics, in addition to being an excellent room temperature altermagnet.
作为一种特殊类型的共线反铁磁性（AFM），交替磁性最近引起了广泛的研究兴趣。交替磁体表现出宇称时间对称性破缺和零净磁化强度，导致动量空间中的能带大量分裂。同时，宇称时间对称性破缺是外尔物理学中非平凡能带拓扑的先决条件。当存在能带交叉时，通常很容易产生外尔节点。理论上已在交替磁体中提出外尔半金属态；截至目前，关于实验观测的报道很少。利用角分辨光电子能谱（ARPES）和第一性原理计算，我们系统地研究了室温交替磁体候选材料CrSb的电子结构。我们清楚地观察到在靠近费米能级的（100）解理侧面上，源于体带拓扑的能带自旋分裂和拓扑表面态的特征。我们的结果表明，CrSb除了是一种优异的室温交替磁体外，还包含有趣的非平凡拓扑外尔物理学。
