title: Strain-induced quantum spin Hall effect in methyl-substituted germanane GeCH3.
abstract: Quantum spin Hall (QSH) insulators exhibit a bulk insulting gap and metallic edge states characterized by nontrivial topology. We investigated the electronic structure of an isolated layer of methyl substituted germanane GeCH3 by density functional calculations (DFT), and its dynamic stability by phonon dispersion calculations. Our results show that an isolated GeCH3 layer has no dynamic instability, and is a QSH insulator under reasonable strain. This QSH insulator has a large enough band gap (up to 108 meV) at 12% strain. The advantageous features of this QSH insulator for practical room-temperature applications are discussed.
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.
authors.forename: Yandong
authors.initials: Y
authors.lastname: Ma
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Dai
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, People's Republic of China.
authors.forename: Baibiao
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8205, USA.
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Whangbo