Atomic-Ordering-Induced Quantum Phase Transition between Topological Crystalline Insulator and Z_2 Topological Insulator  

作　　者：Hui-Xiong Deng Zhi-Gang Song Shu-Shen Li Su-Huai Wei Jun-Wei Luo 邓惠雄;宋志刚;李树深;魏苏淮;骆军委(State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083;University of Chinese Academy of Sciences, Beijing 1000493;Beijing Academy of Quantum Information Sciences, Beijing 100193;Beijing Computational Science Research Center, Beijing 100094)

机构地区：[1]State Key Laboratory of Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083 [2]University of Chinese Academy of Sciences,Beijing 100049 [3]Beijing Academy of Quantum Information Sciences,Beijing 100193 [4]Beijing Computational Science Research Center,Beijing 100094

出　　处：《Chinese Physics Letters》2018年第5期104-109,共6页中国物理快报（英文版）

基　　金：Supported by the Major State Basic Research Development Program of China under Grant No 2016YFB0700700;the National Natural Science Foundation of China(NSFC)under Grants Nos 11634003,11474273,61121491 and U1530401;supported by the National Young 1000 Talents Plan;supported by the Youth Innovation Promotion Association of CAS(2017154)

摘　　要：Topological phase transition in a single material usually refers to transitions between a trivial band insulator and a topological Dirac phase, and the transition may also occur between different classes of topological Dirac phases.It is a fundamental challenge to realize quantum transition between Z_2 nontrivial topological insulator（TI） and topological crystalline insulator（TCI） in one material because Z_2 TI and TCI have different requirements on the number of band inversions. The Z_2 TIs must have an odd number of band inversions over all the time-reversal invariant momenta, whereas the newly discovered TCIs, as a distinct class of the topological Dirac materials protected by the underlying crystalline symmetry, owns an even number of band inversions. Taking PbSnTe_2 alloy as an example, here we demonstrate that the atomic-ordering is an effective way to tune the symmetry of the alloy so that we can electrically switch between TCI phase and Z_2 TI phase in a single material. Our results suggest that the atomic-ordering provides a new platform towards the realization of reversibly switching between different topological phases to explore novel applications.Topological phase transition in a single material usually refers to transitions between a trivial band insulator and a topological Dirac phase, and the transition may also occur between different classes of topological Dirac phases.It is a fundamental challenge to realize quantum transition between Z_2 nontrivial topological insulator（TI） and topological crystalline insulator（TCI） in one material because Z_2 TI and TCI have different requirements on the number of band inversions. The Z_2 TIs must have an odd number of band inversions over all the time-reversal invariant momenta, whereas the newly discovered TCIs, as a distinct class of the topological Dirac materials protected by the underlying crystalline symmetry, owns an even number of band inversions. Taking PbSnTe_2 alloy as an example, here we demonstrate that the atomic-ordering is an effective way to tune the symmetry of the alloy so that we can electrically switch between TCI phase and Z_2 TI phase in a single material. Our results suggest that the atomic-ordering provides a new platform towards the realization of reversibly switching between different topological phases to explore novel applications.

关 键 词：Cu Te Sn TCI Atomic-Ordering-Induced Quantum Phase Transition between Topological Crystalline Insulator and Z2 Topological Insulator Pb Pt 

分 类 号：O469[理学—凝聚态物理]