title: Weak antilocalization effect and noncentrosymmetric superconductivity in a topologically nontrivial semimetal LuPdBi.
abstract: A large number of half-Heusler compounds have been recently proposed as three-dimensional (3D) topological insulators (TIs) with tunable physical properties. However, no transport measurements associated with the topological surface states have been observed in these half-Heusler candidates due to the dominating contribution from bulk electrical conductance. Here we show that, by reducing the mobility of bulk carriers, a two-dimensional (2D) weak antilocalization (WAL) effect, one of the hallmarks of topological surface states, was experimentally revealed from the tilted magnetic field dependence of magnetoconductance in a topologically nontrivial semimetal LuPdBi. Besides the observation of a 2D WAL effect, a superconducting transition was revealed at Tc ~ 1.7 K in the same bulk LuPdBi. Quantitative analysis within the framework of a generalized BCS theory leads to the conclusion that the noncentrosymmetric superconductivity of LuPdBi is fully gapped with a possibly unconventional pairing character. The co-existence of superconductivity and the transport signature of topological surface states in the same bulk alloy suggests that LuPdBi represents a very promising candidate as a topological superconductor.
authors.affiliation: State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Guizhou
authors.initials: G
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Wenhong
authors.initials: W
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Du
authors.affiliation: State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Enke
authors.initials: E
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Shouguo
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Guangheng
authors.initials: G
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Metastable Material Sciences and Technology, Yanshan University, Qinhuangdao 066004, P. R. China.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Division of Physical Science and Engineering and Core Labs, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
authors.forename: Xi Xiang
authors.initials: XX
authors.lastname: Zhang