Strain induced band inversion and topological phase transition in methyl-decorated stanene film

• Published in: Scientific reports Vol. 7; no. 1; pp. 17089 - 8
• Main Authors: Wang, Dongchao, Chen, Li, Liu, Hongmei, Shi, Changmin, Wang, Xiaoli, Cui, Guangliang, Zhang, Pinhua, Chen, Yeqing
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06.12.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/2792; 639/766/119/995; Electronic equipment; Energy consumption; Humanities and Social Sciences; multidisciplinary; Phase transitions; Science; Science (multidisciplinary); Topology
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-17336-8

The researches for new quantum spin Hall (QSH) insulators with large bulk energy gap are of much significance for their practical applications at room temperature in electronic devices with low-energy consumption. By means of first-principles calculations, we proposed that methyl-decorated stanene (SnCH 3 ) film can be tuned into QSH insulator under critical tensile strain of 6%. The nonzero topological invariant and helical edge states further confirm the nontrivial nature in stretched SnCH 3 film. The topological phase transition originates from the s - p xy type band inversion at the Γ point with the strain increased. The spin-orbital coupling (SOC) induces a large band gap of ~0.24 eV, indicating that SnCH 3 film under strain is a quite promising material to achieve QSH effect. The proper substrate, h -BN, finally is presented to support the SnCH 3 film with nontrivial topology preserved.