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Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
Interfacing 2D and 3D topological insulators: Bi(111) bilayer on Bi2Te3
Toru Hirahara1, Gustav Bihlmayer, Yusuke Sakamoto
1Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, Japan. hirahara@surface.phys.s.u-tokyo.ac.jp
Physical Review Letters
|November 24, 2011
Summary
We formed a bilayer Bismuth (Bi) film on a Bismuth telluride (Bi2Te3) substrate, revealing a robust Dirac cone. This study demonstrates the coexistence of one- and two-dimensional topological edge states.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Surface Science
Background:
- Bilayer Bi(111) ultrathin films are theoretically predicted to exhibit a two-dimensional quantum spin Hall state.
- Topological insulators and quantum spin Hall effects are areas of intense research interest.
Purpose of the Study:
- To experimentally investigate the electronic structure of a bilayer Bi(111) ultrathin film on a Bi2Te3 substrate.
- To confirm the theoretical prediction of a two-dimensional quantum spin Hall state in this system.
- To explore the robustness of the Dirac cone and the nature of edge states.
Main Methods:
- Angle-resolved photoemission spectroscopy (ARPES) measurements.
- Ab initio electronic structure calculations.
Main Results:
- The electronic structure shows an overlap of band dispersions from bilayer Bi and the Bi2Te3 substrate.
- The Dirac cone in the system is observed to be robust against nonmagnetic perturbations.
- A unique coexistence of one- and two-dimensional topologically protected edge states at the surface is implied.
Conclusions:
- The experimental findings support the theoretical predictions for the bilayer Bi(111) film.
- The robustness of the Dirac cone and the coexisting edge states present a unique physical system for studying topological phenomena.
