Tuning band inversion symmetry of buckled III-Bi sheets by halogenation

被引：46

作者：

Freitas, R. R. Q. ^{[1
,2
]}

de Brito Mota, F. ^{[1
]}

Rivelino, R. ^{[1
]}

de Castilho, C. M. C. ^{[1
,3
]}

Kakanakova-Georgieva, A. ^{[2
]}

Gueorguiev, G. K. ^{[2
]}

机构：

[1] Univ Fed Bahia, Grp Fis Superficies & Mat, Inst Fis, Campus Univ Federacao, BR-40170115 Salvador, BA, Brazil

[2] Linkoping Univ, Dept Phys Chem & Biol IFM, S-58183 Linkoping, Sweden

[3] Univ Fed Bahia, Inst Nacl Ciencia & Tecnol Energia & Ambiente CIE, Salvador, BA, Brazil

来源：

NANOTECHNOLOGY | 2016年 / 27卷 / 05期

基金：

瑞典研究理事会;

关键词：

bismuth-based 2D materials; topological insulators; halogenation; spin-orbit coupling; TOPOLOGICAL INSULATORS; HALL; BISMUTH;

D O I：

10.1088/0957-4484/27/5/055704

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

First-principles calculations are employed to investigate structural, electronic and topological insulating properties of XBi (X = B, Al, Ga, and In) monolayers upon halogenation. It is known that Y-XBi (X = Ga, In, Tl; Y = F, Cl, Br, I) can originate inversion-asymmetric topological insulators with large bulk band gaps. Our results suggest that Y-XBi (X = B, Al; Y = F, Cl, Br, I) may also result in nontrivial topological insulating phases. Despite the lower atomic number of B and Al, the spin-orbit coupling opens a band gap of about 400 meV in Y-XBi (X = B, Al), exhibiting an unusual electronic behavior for practical applications in spintronics. The nature of the bulk band gap and Dirac-cone edge states in their nanoribbons depends on the group-III elements and Y chemical species. They lead to a chemical tunability, giving rise to distinct band inversion symmetries and exhibiting Rashba-type spin splitting in the valence band of these systems. These findings indicate that a large family of Y-XBi sheets can exhibit nontrivial topological characteristics, by a proper tuning, and open a new possibility for viable applications at room temperature.

引用

页数：11