Low hydrogen coverage [formula omitted] topological phase transition in plumbene

Abstract

Two-dimensional group IV monolayers with low-buckled honeycomb structures are reported as Z2 topological insulators. However, despite the strong spin–orbit coupling, the 2D lead monolayer (known as plumbene) exhibits a trivial insulator electronic state. Here we have studied the possible trivial to Z2 topological phase transition in plumbene monolayer with low-density H decoration using the density-functional theory calculations. The adsorption of the H atom on the plumbene monolayer is energetically favorable. We examined different configurations for the adsorption of one and two H atoms on the plumbene surface. The H decoration of the surface causes the trivial to Z2 topological phase transition in the plumbene monolayer. The topological phase transition depends on the density and order of H atoms on the plumbene surface.