Jiang Xiao, Jeong Uiseok, Sato Shunsuke, Shin Dongbin, Yabana Kazuhiro, Yan Binghai, Park Noejung
Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 689-798, Republic of Korea.
Center for Computational Sciences, University of Tsukuba, Tsukuba 305-8577, Japan.
ACS Nano. 2025 Jul 8;19(26):23620-23628. doi: 10.1021/acsnano.5c01421. Epub 2025 Jun 26.
The recent rise in interest in altermagnetism─a magnetic state distinct from ferromagnetism and antiferromagnetism─nessitates the development of a reliable probing method to distinguish it from other types of compensated magnetism. Here, we investigate nonrelativistic spin groups and relativistic magnetic groups to identify and categorize the permissible spin and charge photocurrents of compensated collinear magnets. Our results indicate that, in altermagnets, the charge and spin photocurrents exhibit a similar temperature profile due to their shared dependence on carrier relaxation effects, whereas in antiferromagnets, these currents behave in stark contrast. As a real-material example, we performed first-principles calculations of the altermagnetic phase of MnO and analyzed it using a simplified four-band model. We demonstrate that the normal injection current directly reflects the magnetic band geometry of altermagnets: the direction and magnitude of the injection current are delicately correlated with the interband Berry curvature and the alternating spin splitting of energy bands. We suggest that nonlinear photocurrent could serve as a promising probing tool to reveal the particular magnetic phase and band geometry of altermagnets.
最近，人们对交替磁性（一种不同于铁磁性和反铁磁性的磁态）的兴趣日益浓厚，这就需要开发一种可靠的探测方法，以将其与其他类型的补偿磁性区分开来。在这里，我们研究非相对论自旋群和相对论磁群，以识别和分类补偿共线磁体中允许的自旋和电荷光电流。我们的结果表明，在交替磁体中，电荷和自旋光电流由于对载流子弛豫效应的共同依赖而呈现出相似的温度分布，而在反铁磁体中，这些电流的行为则截然不同。作为一个实际材料的例子，我们对MnO的交替磁相进行了第一性原理计算，并使用简化的四能带模型对其进行了分析。我们证明，正常注入电流直接反映了交替磁体的磁能带几何结构：注入电流的方向和大小与带间贝里曲率和能带的交替自旋分裂密切相关。我们认为，非线性光电流可以作为一种很有前景的探测工具，用于揭示交替磁体的特定磁相和能带几何结构。
