Linear magnetoresistance versus weak antilocalization effects in Bi2Te3

作     者：ZhenhuaWang Liang Yang Xiaotian Zhao Zhidong Zhang Xuan P. A. Gao 

作者机构：Shenyang National Laboratory far Materials Science Institute of Metal Research Chinese Academy of Sciences 72 Wenhua Road Shenyang 110016 China Department of Physics Case Western Reserve University Cleveland Ohio 44106 USA 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2015年第8卷第9期

页      面：2963-2969页

核心收录：

学科分类：07[理学] 

基　　金：the NSF CAREER Award program for financial support of research at CWRU the Lee Hsun Young Scientist award of IMR, Chinese Academy of Sciences 国家自然科学基金 

主　　题：linear magnetoresistanqweak antilocalization,Bi2Te3 films,topological insulators 

摘      要：In chalcogenide topological insulator materials, two types of magnetoresistance （MR） effects are widely discussed： a sharp MR dip around zero magnetic field, associated with the weak antilocalization （WAL） effect, and a linear MR （LMR） effect that generally persists to high fields and high temperatures. We have studied the MR of thin films of the topological insulator Bi2Te3 from the metallic to semiconducting transport regime. In the metallic samples, the WAL is difficult to identify owing to the low magnitude of the WAL compared to the samples＇ conductivity. Furthermore, the sharp WAL dip in the MR is dearly present in samples with a higher resistivity. To correctly account for the low-field MR with the quantitative theory of the WAL according to the Hikami-Larkin-Nagaoka （HLN） model, we find that the classical （linear） MR effect should be taken into account in combination with the WAL quantum correction. Otherwise, the WAL fitting alone yields an unrealistically large coefficient in the HLN analysis. This work clarifies the WAL and LMR as two distinct effects and offers an explanation for the overly large a in the WAL analysis of topological insulators in some studies.