Jing Yumei, Huang Shaoyun, Zhang Kai, Wu Jinxiong, Guo Yunfan, Peng Hailin, Liu Zhongfan, Xu H Q
Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China.
Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Nanoscale. 2016 Jan 28;8(4):1879-85. doi: 10.1039/c5nr07296d.
The electron transport properties of a topological insulator Bi2Se3 thin film are studied in Hall-bar geometry. The film with a thickness of 10 nm is grown by van der Waals epitaxy on fluorophlogopite mica and Hall-bar devices are fabricated from the as-grown film directly on the mica substrate. Weak antilocalization and electron-electron interaction effects are observed and analyzed at low temperatures. The phase-coherence length extracted from the measured weak antilocalization characteristics shows a strong power-law increase with decreasing temperature and the transport in the film is shown to occur via coupled multiple (topological surface and bulk states) channels. The conductivity of the film shows a logarithmical decrease with decreasing temperature and thus the electron-electron interaction plays a dominant role in quantum corrections to the conductivity of the film at low temperatures.
在霍尔条形结构中研究了拓扑绝缘体Bi2Se3薄膜的电子输运性质。通过范德华外延在氟金云母上生长了厚度为10nm的薄膜，并直接在云母衬底上由生长好的薄膜制备了霍尔条形器件。在低温下观察并分析了弱反局域化和电子-电子相互作用效应。从测量的弱反局域化特性中提取的相位相干长度随温度降低呈现出强烈的幂律增长，并且表明薄膜中的输运是通过多个耦合通道（拓扑表面态和体态）发生的。薄膜的电导率随温度降低呈对数下降，因此在低温下电子-电子相互作用在薄膜电导率的量子修正中起主导作用。
