Transport signatures of the topological surface state induced by the size effect in superconductor β-PdBi_(2)  

作　　者：Ankang Zhu Zheng Chen Yuyan Han Mengcheng Zhu Huanhuan Wang Minglong Han Liang Li Xue Liu Guolin Zheng Xiangde Zhu Wenshuai Gao Mingliang Tian 

机构地区：[1]Information Materials and Intelligent Sensing Laboratory of Anhui Province,Institutes of Physical Science and Information Technology,Anhui University,Hefei 230601,China [2]Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions,High Magnetic Field Laboratory,Chinese Academy of Sciences,Hefei 230031,China [3]Key Laboratory of Materials Physics,Institute of Solid State Physics,Chinese Academy of Sciences,Hefei 230601,China [4]School of Physics and Optoelectronics Engineering,Anhui University,Hefei 230031,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2023年第7期94-101,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.U19A2093,11904002,and U2032163);the National Key Research and Development Program of China(Grant No.2021YFA1600201);the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2021117)。

摘　　要：The superconductivity and nontrivial topological electronic state are key hallmarks of topological superconductors.Here,we focus on the transport signals of possible topological surface state in the topological superconductor candidate β-PdBi_(2) nanoflake with a thickness of 21 nm.The resistance demonstrates a semiconductor-metal transition followed by an upturned behavior as the temperature decreases.A large and unsaturated longitudinal magnetoresistance(MR),accompanied by distinct Shubnikov-de Hass oscillation in Hall resistance,is observed.An analysis of Hall resistance reveals that the carriers present the characteristics of relativistic particles with small effective mass and extremely high mobility.The angle-dependent quantum oscillations demonstrate a two-dimensional Fermi surface topology.A giant anisotropic MR as large as 98%is detected when rotating the magnetic field.These results provide the possible transport signals of a nontrivial topological electronic state,establishing a further understanding of the topological properties of the low-dimensional topological superconductor candidate β-PdBi_(2).

关 键 词：MAGNETOTRANSPORT surface state LOW-DIMENSIONAL 

分 类 号：O469[理学—凝聚态物理]