Non-Stoichiometry Effects on the Extreme Magnetoresistance in Weyl Semimetal WTe2  

作　　者：Ji-Xiang Gong Jun Yang Min Ge Yong-Jian Wang Dan-Dan Liang Lei Luo Xiu Yan Shi-Rui Weng Li Pi Chang-Jin Zhang Wen-Ka Zhu 龚吉祥;杨军;葛敏;王永建;梁丹丹;骆磊;严秀;甄伟立;翁士瑞;皮雳;张昌锦;朱文卡(High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031;Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China Hefei 230026;Institute of Physical Science and Information Technology, Anhui University, Hefei 230601)

机构地区：[1]High Magnetic Field Laboratory,Chinese Academy of Sciences,Hefei 230031 [2]Hefei National Laboratory for Physical Sciences at Mieroscale,University of Science and Technology of China Hefei 230026 [3]Institute of Physical Science and Information Technology,Anhui University,Hefei 230601

出　　处：《Chinese Physics Letters》2018年第9期57-61,共5页中国物理快报（英文版）

基　　金：Supported by the National Key R&D Program of China under Grant Nos 2016YFA0300404 and 2017YFA0403600;the National Natural Science Foundation of China under Grant Nos 51603207,U1532267,11574288 and 11674327;the Natural Science Foundation of Anhui Province under Grant No 1708085MA08

摘　　要：Non-stoiehiometry effect on the extreme magnetoresistanee is systematically investigated for the Weyl semimetal WTe2. Magnetoresistance and Hall resistivity are measured for the as-grown samples with a slight difference in Te vacancies and the annealed samples with increased Te vacancies. The fits to a two-band model show that the magnetoresistanee is strongly dependent on the residual resistivity ratio （i.e., the degree of non-stoichiometry）, which is eventually understood in terms of electron doping that not only breaks the balance between electron-type and hole-type carrier densities, but also reduces the average carrier mobility. Thus the compensation effect and ultrahigh mobility are probably the main driving force of the extreme magnetoresistance in WTe2.Non-stoiehiometry effect on the extreme magnetoresistanee is systematically investigated for the Weyl semimetal WTe2. Magnetoresistance and Hall resistivity are measured for the as-grown samples with a slight difference in Te vacancies and the annealed samples with increased Te vacancies. The fits to a two-band model show that the magnetoresistanee is strongly dependent on the residual resistivity ratio （i.e., the degree of non-stoichiometry）, which is eventually understood in terms of electron doping that not only breaks the balance between electron-type and hole-type carrier densities, but also reduces the average carrier mobility. Thus the compensation effect and ultrahigh mobility are probably the main driving force of the extreme magnetoresistance in WTe2.

关 键 词：Te MR Non-Stoichiometry Effects on the Extreme Magnetoresistance in Weyl Semimetal WTe2 

分 类 号：O469[理学—凝聚态物理]