Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
Nature. 2021 Nov;599(7886):576-581. doi: 10.1038/s41586-021-04028-7. Epub 2021 Nov 24.
Efficient magnetic control of electronic conduction is at the heart of spintronic functionality for memory and logic applications. Magnets with topological band crossings serve as a good material platform for such control, because their topological band degeneracy can be readily tuned by spin configurations, dramatically modulating electronic conduction. Here we propose that the topological nodal-line degeneracy of spin-polarized bands in magnetic semiconductors induces an extremely large angular response of magnetotransport. Taking a layered ferrimagnet, MnSiTe, and its derived compounds as a model system, we show that the topological band degeneracy, driven by chiral molecular orbital states, is lifted depending on spin orientation, which leads to a metal-insulator transition in the same ferrimagnetic phase. The resulting variation of angular magnetoresistance with rotating magnetization exceeds a trillion per cent per radian, which we call colossal angular magnetoresistance. Our findings demonstrate that magnetic nodal-line semiconductors are a promising platform for realizing extremely sensitive spin- and orbital-dependent functionalities.
电子输运的高效磁控制是用于内存和逻辑应用的自旋电子学功能的核心。具有拓扑带交叉的磁铁是这种控制的良好材料平台，因为它们的拓扑带简并性可以通过自旋构型轻松调节，从而显著调节电子输运。在这里，我们提出磁性半导体中自旋极化带的拓扑节线简并导致磁输运的极大约束角响应。以层状亚铁磁体 MnSiTe 及其衍生化合物作为模型系统，我们表明，由手性分子轨道态驱动的拓扑带简并性取决于自旋取向，这导致相同亚铁磁相中发生金属-绝缘体转变。旋转磁化引起的角磁电阻的变化超过每弧度万亿分之百，我们称之为巨大角磁电阻。我们的发现表明，磁性节线半导体是实现极其敏感的自旋和轨道相关功能的有前途的平台。
