Influence of Device Geometry on Transport Properties of Topological Insulator Microflakes  

作　　者：Fan Gao Yongqing Li 高凡;李永庆(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Songshan Lake Materials Laboratory,Dongguan 523808,China;CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China [3]Songshan Lake Materials Laboratory,Dongguan 523808,China [4]CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Chinese Physics Letters》2021年第11期72-76,共5页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grant No. 11961141011);the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000);the National Key Research and Development Program of China(Grant No. 2016YFA0300600)。

摘　　要：In the transport studies of topological insulators, microflakes exfoliated from bulk single crystals are often used because of the convenience in sample preparation and the accessibility to high carrier mobilities. Here, based on finite element analysis, we show that for the non-Hall-bar shaped topological insulator samples, the measured four-point resistances can be substantially modified by the sample geometry, bulk and surface resistivities,and magnetic field. Geometry correction factors must be introduced for accurately converting the four-point resistances to the longitudinal resistivity and Hall resistivity. The magnetic field dependence of inhomogeneous current density distribution can lead to pronounced positive magnetoresistance and nonlinear Hall effect that would not exist in the samples of ideal Hall bar geometry.

关 键 词：Influence of Device Geometry on Transport Properties of Topological Insulator Microflakes 

分 类 号：TB34[一般工业技术—材料科学与工程]