Deng Peng, Grutter Alexander, Han Yulei, Holtz Megan E, Zhang Peng, Quarterman Patrick, Pan Shuaihang, Qi Shifei, Qiao Zhenhua, Wang Kang L
Department of Electrical and Computer Engineering, University of California, Los Angeles, California 90095, United States.
Beijing Academy of Quantum Information Science, Beijing 100193, China.
Nano Lett. 2022 Jul 27;22(14):5735-5741. doi: 10.1021/acs.nanolett.2c00774. Epub 2022 Jul 19.
Topological surface states are a new class of electronic states with novel properties, including the potential for annihilation between surface states from two topological insulators at a common interface. Here, we report the annihilation and creation of topological surface states in the SnTe/Cr(BiSb)Te (CBST) heterostructures as evidenced by magneto-transport, polarized neutron reflectometry, and first-principles calculations. Our results show that topological surface states are induced in the otherwise topologically trivial two-quintuple-layers thick CBST when interfaced with SnTe, as a result of the surface state annihilation at the SnTe/CBST interface. Moreover, we unveiled systematic changes in the transport behaviors of the heterostructures with respect to changing Fermi level and thickness. Our observation of surface state creation and annihilation demonstrates a promising way of designing and engineering topological surface states for dissipationless electronics.
拓扑表面态是一类具有新奇特性的新型电子态，包括在两个拓扑绝缘体的公共界面处表面态之间可能发生湮灭。在此，我们报道了在SnTe/Cr(BiSb)Te（CBST）异质结构中拓扑表面态的湮灭和产生，这通过磁输运、极化中子反射测量和第一性原理计算得到了证实。我们的结果表明，当与SnTe界面时，原本拓扑平凡的两层五重层厚的CBST中会诱导出拓扑表面态，这是由于SnTe/CBST界面处的表面态湮灭所致。此外，我们揭示了异质结构的输运行为随费米能级和厚度变化的系统变化。我们对表面态产生和湮灭的观察展示了一种为无耗散电子学设计和调控拓扑表面态的有前景的方法。
