High-buckled 3×3 stanene with a topologically nontrivial energy gap

Abstract

Abstract We demonstrate an efficient way of tuning the atomic buckling in stanene to open a topologically nontrivial energy gap. By tuning the growth kinetics, we obtain an unexpected high-buckled 3 × 3 stanene on the Bi(111) substrate. Scanning tunneling microscopy study combined with density functional theory calculation confirms that the 3 × 3 stanene is a distorted 1 × 1 structure with a high-buckled Sn in every three 1 × 1 unit cells. The high-buckled 3 × 3 stanene favors a large band inversion at the Γ point, and the spin–orbit coupling opens a topologically nontrivial energy gap. This study provides an alternate way to tune the topology of monolayer topological materials.