Yin Jia-Xin, Shumiya Nana, Jiang Yuxiao, Zhou Huibin, Macam Gennevieve, Sura Hano Omar Mohammad, Zhang Songtian S, Cheng Zi-Jia, Guguchia Zurab, Li Yangmu, Wang Qi, Litskevich Maksim, Belopolski Ilya, Yang Xian P, Cochran Tyler A, Chang Guoqing, Zhang Qi, Huang Zhi-Quan, Chuang Feng-Chuan, Lin Hsin, Lei Hechang, Andersen Brian M, Wang Ziqiang, Jia Shuang, Hasan M Zahid
Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, 08544, USA.
International Center for Quantum Materials and School of Physics, Peking University, 100193, Beijing, China.
Nat Commun. 2020 Sep 4;11(1):4415. doi: 10.1038/s41467-020-18111-6.
Quantum states induced by single-atomic impurities are at the frontier of physics and material science. While such states have been reported in high-temperature superconductors and dilute magnetic semiconductors, they are unexplored in topological magnets which can feature spin-orbit tunability. Here we use spin-polarized scanning tunneling microscopy/spectroscopy (STM/S) to study the engineered quantum impurity in a topological magnet CoSnS. We find that each substituted In impurity introduces a striking localized bound state. Our systematic magnetization-polarized probe reveals that this bound state is spin-down polarized, in lock with a negative orbital magnetization. Moreover, the magnetic bound states of neighboring impurities interact to form quantized orbitals, exhibiting an intriguing spin-orbit splitting, analogous to the splitting of the topological fermion line. Our work collectively demonstrates the strong spin-orbit effect of the single-atomic impurity at the quantum level, suggesting that a nonmagnetic impurity can introduce spin-orbit coupled magnetic resonance in topological magnets.
由单原子杂质诱导产生的量子态处于物理学和材料科学的前沿。虽然在高温超导体和稀磁半导体中已报道过此类量子态，但在具有自旋轨道可调性的拓扑磁体中尚未得到探索。在此，我们利用自旋极化扫描隧道显微镜/能谱（STM/S）研究拓扑磁体CoSnS中的工程量子杂质。我们发现，每个取代的In杂质都会引入一个显著的局域束缚态。我们系统的磁化极化探针显示，这个束缚态是自旋向下极化的，与负轨道磁化相一致。此外，相邻杂质的磁束缚态相互作用形成量子化轨道，呈现出有趣的自旋轨道分裂，类似于拓扑费米子线的分裂。我们的工作共同证明了单原子杂质在量子水平上具有强大的自旋轨道效应，这表明非磁性杂质可以在拓扑磁体中引入自旋轨道耦合磁共振。
