Single-surface conduction in a highly bulk-resistive topological insulator Sn0.02Bi1.08Sb0.9Te2S using the Corbino geometry
Single-surface conduction in a highly bulk-resistive topological insulator Sn0.02Bi1.08Sb0.9Te2S using the Corbino geometry
复制标题
DOI：
10.1063/5.0026730
复制
发表时间：
2021-01
影响因子：
4
通讯作者：
T. Misawa;S. Nakamura;Y. Okazaki;Y. Fukuyama;Nariaki Nasaka;Hiroki Ezure;C. Urano;N. Kaneko;T. Sasagawa
中科院分区：
文献类型：
--
作者：
T. Misawa;S. Nakamura;Y. Okazaki;Y. Fukuyama;Nariaki Nasaka;Hiroki Ezure;C. Urano;N. Kaneko;T. Sasagawa
为了实现拓扑绝缘体的单面导电，用高体电阻拓扑绝缘体Sn0.02Bi1.08Sb0.9Te2S(SnBSTS)单晶制备了微尺度的Corbino器件。在2K-300K范围内测量了四端电阻，发现Corbino器件的电阻随温度的变化明显不同于SnBSTS块体样品。结果表明，通过将上表面、下表面和体相视为相互独立的传导路径，我们可以定量地理解Corbino器件的非常规行为。此外，通过引入电阻网络模型研究了电流分布，结果表明，在较低的温度下实现了顶面主导导电。这项研究证明了科尔比诺几何在测量拓扑绝缘子输运方面的有效性。
To realize the single-surface conduction in a topological insulator, a microscale Corbino device was fabricated from a single crystal of a highly bulk-resistive topological insulator Sn0.02Bi1.08Sb0.9Te2S (Sn-BSTS). The four-terminal resistance was measured in 2 K–300 K, and it was found that the temperature dependence of the resistance of the Corbino device was clearly distinct from that of Sn-BSTS bulk samples. We showed that the unconventional behavior of the Corbino device was quantitatively understood by considering the top surface, bottom surface, and bulk as independent conduction paths in parallel. Furthermore, the current flow distribution was studied by introducing the resistance network model, which revealed that the top-surface dominant conduction was realized in a low temperature. This study demonstrates the usefulness of the Corbino geometry for transport measurement in topological insulators.