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

• Several proposed applications and exotic effects in topological insulators rely on the presence of helical Dirac states at the interface between a topological insulator 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 heterostructures 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.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

Topological insulator

bismuth selenide

interface state

surface state

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)