title: Functionalized Thallium Antimony Films as Excellent Candidates for Large-Gap Quantum Spin Hall Insulator.
abstract: Group III-V films are of great importance for their potential application in spintronics and quantum computing. Search for two-dimensional III-V films with a nontrivial large-gap are quite crucial for the realization of dissipationless transport edge channels using quantum spin Hall (QSH) effects. Here we use first-principles calculations to predict a class of large-gap QSH insulators in functionalized TlSb monolayers (TlSbX2; (X = H, F, Cl, Br, I)), with sizable bulk gaps as large as 0.22~0.40 eV. The QSH state is identified by Z2 topological invariant together with helical edge states induced by spin-orbit coupling (SOC). Noticeably, the inverted band gap in the nontrivial states can be effectively tuned by the electric field and strain. Additionally, these films on BN substrate also maintain a nontrivial QSH state, which harbors a Dirac cone lying within the band gap. These findings may shed new light in future design and fabrication of QSH insulators based on two-dimensional honeycomb lattices in spintronics.
authors.affiliation: School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, People's Republic of China.
authors.forename: Run-wu
authors.initials: RW
authors.lastname: Zhang
authors.affiliation: School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, People's Republic of China.
authors.forename: Chang-wen
authors.initials: CW
authors.lastname: Zhang
authors.affiliation: School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, People's Republic of China.
authors.forename: Wei-xiao
authors.initials: WX
authors.lastname: Ji
authors.affiliation: School of Physics, State Key laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, People's Republic of China.
authors.forename: Sheng-shi
authors.initials: SS
authors.lastname: Li
authors.affiliation: School of Physics, State Key laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, People's Republic of China.
authors.forename: Shi-shen
authors.initials: SS
authors.lastname: Yan
authors.affiliation: School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, People's Republic of China.
authors.forename: Pei-ji
authors.initials: PJ
authors.lastname: Wang