Direct observation of decoupled Dirac states at the interface between topological and normal insulators

2012/06/30 by M. H. Berntsen, O. Götberg, B. M. Wojek +1 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci

paper · pdf · doi:10.1103/physrevb.88.195132

published as Phys. Rev. B 88, 195132 (2013) · 9 pages, 5 figures

arxiv created 2013/11/02 · arxiv updated 2013/11/20

Abstract

Several proposed applications and exotic effects in topological insulators rely on the presence of helical Dirac states at the interface between a topological and a normal insulator. In the present work, we have used low-energy angle-resolved photoelectron spectroscopy to uncover and characterize the interface states of Bi₂Se₃ thin films and Bi₂Te₃/Bi₂Se₃ heterostuctures grown on Si(111). The results establish that Dirac fermions are indeed present at the topological-normal-insulator boundary and absent at the topological-topological-insulator interface. Moreover, it is demonstrated that band bending present within the topological-insulator films leads to a substantial separation of the interface and surface states in energy. These results pave the way for further studies and the realization of interface-related phenomena in topological-insulator thin-film heterostructures.

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