Regulation of the electronic structure and ferromagnetism by implanting topological defects in a bismuth monolayer

Abstract

Bismuth (Bi) monolayers have attracted much attention due to their intriguing physical and chemical applications, which are strongly related to the existence of topological defects. However, the intrinsic correlation between the defect types and particular electronic structures of Bi monolayers still needs to be understood. Herein, we intentionally implanted various typical topological defects into Bi monolayers to reveal the differences in the electronic structure, in which the monovacancies (MVs) can lead to a transformation from a semiconductor to a metal. More interestingly, a particular defect configuration can give rise to a spin polarization and room-temperature ferromagnetism, demonstrating the spintronic applications. This work reveals that the physical property differences of Bi monolayers are strongly dependent on their defect types.