title: Topological Properties of Atomic Lead Film with Honeycomb Structure.
abstract: Large bandgap is desired for the fundamental research as well as applications of topological insulators. Based on first-principles calculations, here we predict a new family of two-dimensional (2D) topological insulators in functionalized atomic lead films Pb-X (X = H, F, Cl, Br, I and SiH3). All of them have large bandgaps with the largest one above 1 eV, far beyond the recorded gap values and large enough for practical applications even at room temperature. Besides chemical functionalization, external strain can also effectively tune the bandgap while keeping the topological phase. Thus, the topological properties of these materials are quite robust, and as a result there exist 1D topological edge channels against backscattering. We further show that the 2D Pb structure can be encapsulated by SiO2 with very small lattice mismatch and still maintains its topological character. All these features make the 2D atomic Pb films a promising platform for fabricating novel topological electronic devices.
authors.affiliation: School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.|State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
authors.forename: Y H
authors.initials: YH
authors.lastname: Lu
authors.affiliation: School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.|State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
authors.forename: D
authors.initials: D
authors.lastname: Zhou
authors.affiliation: College of Electrical Engineering, Zhejiang University, Hangzhou, 310027, China.
authors.forename: T
authors.initials: T
authors.lastname: Wang
authors.affiliation: Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore.
authors.forename: Shengyuan A
authors.initials: SA
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.|State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, China.
authors.forename: J Z
authors.initials: JZ
authors.lastname: Jiang