文献类型：期刊文献

英文题名：Prediction of Dirac semimetals and hourglass surface states in stacked hydrogenated Xenes (X = Sn and Pb)

作者：Gao, Guanyi[1,2,3];Huan, Hao[1,2,3];Bao, Hairui[1,2,3];Xue, Yang[1,2,3,4];Zhao, Bao[1,2,3,5];Yu, Rui[6];Yang, Zhongqin[1,2,3,7]

机构：[1]Fudan Univ, State Key Lab Surface Phys, Shanghai 200433, Peoples R China;[2]Fudan Univ, Key Lab Computat Phys Sci MOE, Shanghai 200433, Peoples R China;[3]Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China;[4]East China Univ Sci & Technol, Sch Sci, Shanghai 200237, Peoples R China;[5]Liaocheng Univ, Sch Phys Sci & Informat Technol, Shandong Key Lab Opt Commun Sci & Technol, Liaocheng 252059, Shandong, Peoples R China;[6]Wuhan Univ, Sch Phys & Technol, Wuhan 430072, Hubei, Peoples R China;[7]Collaborat Innovat Ctr Adv Microstruct, Nanjing 210093, Peoples R China

年份：2020

卷号：102

期号：20

外文期刊名：PHYSICAL REVIEW B

收录：;EI(收录号：20204909595843);WOS:【SCI-EXPANDED(收录号:WOS:000588581200002)】；

基金：This work was supported by National Natural Science Foundation of China under Grants No. 11574051, No. 11874117, No. 11604134, and No. 11904101. The calculations were performed at the High Performance Computational Center (HPCC) of the Department of Physics at Fudan University.

语种：英文

外文关键词：Surface states - Crystal symmetry - Crystals - Hydrogenation - Tin compounds - Topology - Tin

摘要：Based on density-functional theory calculations and symmetry analysis, topological Dirac semimetals (DSMs) and exotic hourglass surface states are predicted in stacked hydrogenated stanene and plumbene [Xenes (X = Sn and Pb)]. Two types of topologically nontrivial DSMs are predicted in the hydrogenated Xene crystals, with the two most stable stacking patterns, respectively. The Dirac points in SnH are found occurring along the three- or sixfold (screw) rotation axes due to the inversion of the Sn 5s (5p(z)) and Sn 5p(x,y) bands. The unique Fermi arcs are observed on the surfaces parallel to the rotation axes in the crystals. Very specially, the nonsymmorphic symmetry of a glide-mirror plane in the hydrogenated Xene crystals gives rise to exotic hourglass surface states which can lead to a giant value of spin-Hall conductivity and make the crystals be ideal systems applied in prospective dissipationless spintronics. The topological nature of the both types of the DSMs is identified by the calculations of the Z(2) indexes. Phase transitions from topologically nontrivial DSM states to normal insulators (NIs) or to other types of DSMs are also investigated. Our work provides an ideal material platform for carrying out DSMs and a comprehensive study for understanding how DSMs evolve from two-dimensional NIs or quantum spin Hall materials.