非中心对称拓扑狄拉克半金属的研究进展  

Research progress on noncentrosymmetric topological Dirac semimetals

作　　者：高恒 胡顺波 任伟[1,2] GAO Heng;HU Shunbo;REN Wei(College of Sciences,Shanghai University,Shanghai 200444,China;International Centre for Quantum and Molecular Structure,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学理学院,上海200444 [2]上海大学量子与分子结构国际研究中心,上海200444

出　　处：《上海大学学报（自然科学版）》2022年第5期768-779,共12页Journal of Shanghai University:Natural Science Edition

基　　金：上海市“科技创新行动计划”启明星资助项目(扬帆专项)(22YF1413300);上海市优秀学术带头人计划资助项目(22XD1400900);国家自然科学基金资助项目(11929401,12074241,52130204)。

摘　　要：狄拉克半金属由于其新奇的电子结构和输运性质,受到了实验和理论学者广泛的关注.该拓扑材料在费米能级附近存在受对称性保护的狄拉克点,是由于固体中导带和价带的能带反转导致的.本综述介绍了中心对称拓扑狄拉克半金属,并且引入了一种新的三维非中心对称拓扑狄拉克半金属.通过晶体结构对称性和能带对称性分析可知,具有C或C点群的晶体可以实现非中心对称拓扑狄拉克半金属.具有C点群对称性的BiPdO晶体被理论预测为非中心对称的狄拉克半金属,并且在四重旋转轴上可以实现第二类型的拓扑狄拉克点.此外,具有C点群对称性的SrHgPb晶体和LiZnSbBi合金可以实现狄拉克点与外尔点共存的拓扑半金属,并且在LiZnSbBi合金中外尔点的出现和位置可以通过元素成分比例x调控.与中心对称拓扑狄拉克半金属相比,非中心对称拓扑狄拉克半金属由于中心反演对称性的破缺,在非线性光学和非线性霍尔输运等方面有潜在的应用.Dirac semimetals have received extensive attention both experimentally and theoretically because of their novel electronic structures and transport properties.Topological Dirac semimetals have symmetry-protected Dirac points near the Fermi level,where the Dirac points are due to the formation of band inversions between the conduction and valence bands in solids.In this review,we introduce centrosymmetric topological Dirac semimetals and a new three-dimensional noncentrosymmetric topological Dirac semimetal.Through the analysis of crystal symmetry and energy band symmetry,one finds that crystals with Cor Cpoint groups can realize noncentrosymmetric topological Dirac semimetals.BiPdOcrystal with Cpoint group is theoretically predicted to be noncentrosymmetric Dirac semimetals with topological typeⅡDirac points on the Crotation axis.In addition,SrHgPb crystal and LiZnSbBialloys with Cpoint group are predicted to realize topological semimetals in which Dirac and Weyl points coexist,and the appearance and location of Weyl points in LiZnSbBialloys can be regulated by the alloy concentration x.Compared with centrosymmetric topological Dirac semimetals,noncentrosymmetric topological Dirac semimetals have potential applications in nonlinear optics and nonlinear Hall transport due to the broken inversion symmetry.

关 键 词：非中心对称 狄拉克半金属 量子材料 材料设计 

分 类 号：O469[理学—凝聚态物理]