Manipulating topological properties in Bi2Se3/BiSe /transition metal dichalcogenide heterostructures with interface charge transfer

The 3D topological insulator Bi₂Se₃ transitions to a trivial insulator under the 2D limit. Through first-principles studies, the authors show here that significant charge transfer occurs at the Bi₂Se₃/BiSe/transition metal dichalcogenide heterostructure interfaces that stabilizes the BiSe layer as an electron donor and the resulting dipole field breaks the inversion symmetry of the Bi₂Se₃ layer. This results in giant Rashba band splitting and the reemergence of the Dirac states in thin Bi₂Se₃ layers.