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

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 Bi${}_2$Se${}_3$ thin films and Bi${}_2$Te${}_3$/Bi${}_2$Se${}_3$ 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.

9 pages, 5 figures

References in corpus (8)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Topological Insulator Materials
• Exciton condensation and charge fractionalization in a topological insulator film
• Surface States of Topological Insulators
• Manipulation of Topological States and Bulk Band Gap Using Natural Heterostructures of a Topological Insulator
• The fate of topological-insulator surface states under strong disorder

Cited by in corpus (12)

• Ultrafast helicity control of surface currents in topological insulators with near-unity fidelity
• Observation of Quantum-Tunneling Modulated Spin Texture in Ultrathin Topological Insulator Bi2Se3 Films
• Modeling Near-Surface Bound Electron States in Three-Dimensional Topological Insulator: Analytical and Numerical Approaches
• Band bending at the surface of Bi${}_2$Se${}_3$ studied from first principles
• Interface symmetry and spin control in topological insulator-semiconductor heterostructures
• Chemical Potential Fluctuations in Topological Insulator (Bi${}_{0.5}$Sb${}_{0.5}$)${}_2$Te${}_3$ Films Visualized by Photocurrent Spectroscopy
• Lattice-matched heterojunctions between topological and normal insulators: A first-principles study
• Gate field effects on the topological insulator BiSbTeSe2 interface
• Fragility of the Dirac Cone Splitting in Topological Crystalline Insulator Heterostructures
• Topological superconductivity in an ultrathin, magnetically-doped topological insulator proximity coupled to a conventional superconductor
• RF compressibility of topological surface and interface states in metal-hBN-Bi2Se3 capacitors
• Robust interface-state laser in non-Hermitian micro-resonator arrays