文献类型：期刊文献

英文题名：Quantum oscillations and nontrivial topological state in a compensated semimetal TaP2

作者：Wang, Hongyuan[1,2,3];Su, Hao[1,2];Zhang, Jiuyang[4];Xia, Wei[1,2,3];Lin, Yishi[5,6];Liu, Mole[1,2];Hou, Xiaofei[1];Yu, Zhenhai[1];Yu, Na[7];Wang, Xia[7];Zou, Zhiqiang[7];Wang, Yihua[5,6];Liang, Qifeng[8];Zhen, Yuhua[4];Guo, Yanfeng[1,2]

机构：[1]ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 201210, Peoples R China;[2]Univ Chinese Acad Sci, Beijing 100049, Peoples R China;[3]Chinese Acad Sci, Shanghai Inst Opt & Fine Mech, Shanghai 201800, Peoples R China;[4]China Univ Petr, Sch Mat Sci & Engn, Qingdao 266580, Shandong, Peoples R China;[5]Fudan Univ, Dept Phys, Shanghai 200438, Peoples R China;[6]Fudan Univ, State Key Lab Surface Phys, Shanghai 200438, Peoples R China;[7]ShanghaiTech Univ, Sch Phys Sci & Technol, Analyt Instrumentat Ctr, Shanghai 201210, Peoples R China;[8]Univ Shaoxing, Dept Phys, Shaoxing 312000, Peoples R China

年份：2019

卷号：100

期号：11

外文期刊名：PHYSICAL REVIEW B

收录：SCI-EXPANDED(收录号：WOS:000485761800001)、、EI(收录号：20194007493656)、Scopus(收录号：2-s2.0-85072805289)、WOS

基金：The authors acknowledge the support by the Natural Science Foundation of Shanghai (Grant No. 17ZR1443300), the Shanghai Pujiang Program (Grant No. 17PJ1406200), and the National Natural Science Foundation of China (Grants No. 11874264, No. 51772168, and No. 11574215).

语种：英文

外文关键词：Calculations - Quantum theory - Tantalum compounds - Topological insulators - Topology - Transition metals

外文摘要：We report systematic magnetotransport measurements and ab initio calculations on single-crystalline TaP2, a member of the transition-metal dipnictides. We observed unsaturated magnetoresistance (MR) reaching similar to 700% at a magnetic field (B) of 9 T at 2 K when B is perpendicular to the electric current (I). We also found negative longitudinal MR (n-LMR) when B slightly deviates from the direction of I along with striking Shubnikov-de Haas (SdH) oscillations. Our analysis on the SdH oscillations uncovers three fundamental magnetic oscillation frequencies of 72, 237, and 356 T, slightly different from the theoretical calculations which reveal one hole pocket and two electron pockets at the L point and one electron pocket at the Z point of the Brillouin zone. The inconsistency might be due to that one Fermi pocket is out of the detection capability by our measurements. The analysis also reveals a nonzero Berry phase, indicating nontrivial band topology. The n-LMR could be fitted with the Adler-Bell-Jackiw chiral anomaly equation but the origin remains yet ambiguous. The ab initio calculations suggest TaP2 as a weak topological insulator with the Z(2) indices of (0; 111), which exhibits topological surface states on the (001) surface.