1206.4183 (M. H. Berntsen et al.)

Direct observation of Dirac interface states at the Bi2Se3/Si(111)
interface    [PDF]

M. H. Berntsen, O. Götberg, O. Tjernberg

Topological insulators with mass-less helical Dirac fermions on their surface have attracted considerable attention in recent years. Several exotic effects and proposed applications rely on the presence of such states also at the interface between a topological insulator and a trivial insulator. In the present work, we have used low-energy angle-resolved photoelectron spectroscopy to demonstrate and characterize the interface states at the substrate interface in Bi2Se3 thin films grown on Si(111). The results establish that Dirac fermions are indeed present also at the interface. It is also shown that the interface states are shifted in energy with respect to the surface states due to band bending in the film. The observation of topological interface states paves the way for further studies of interface related phenomena involving topological insulator thin films.

View original: http://arxiv.org/abs/1206.4183