The stability and the electronic structure of ultrathin Bi/Bi2Se3 heterostructure

The stability and the electronic structure of ultrathin Bi/Bi2Se3 heterostructure are studied from density-functional theory by including spin-orbit coupling. Our calculations show that the thinnest and dynamically stable heterostructure is one bilayer Bi deposited on Bi2Se3 with the thickness of two quintuple layers. Due to charge transfer and the strong hybridize effect at the interface, the band structure of ultrathin heterostructure make a large change, but the Dirac-like surface states persist. Our findings propose the possibility to engineer heterostructure to obtain ultrathin topological materials.