Topological Control: Systematic control of topological insulator Dirac fermion density on the surface of Bi2Te3

Abstract

Three dimensional (3D) topological insulators are quantum materials with a spin-orbit induced bulk insulating gap that exhibit quantum-Hall-like phenomena in the absence of applied magnetic fields. The proposed applications of topological insulators in device geometries rely on the ability to tune the chemical potential on their surfaces in the vicinity of the Dirac node. Here, we demonstrate a suite of surface control methods based on a combination of photo-doping and molecular-doping to systematically tune the Dirac fermion density on the topological (111) surface of Bi2Te3. Their efficacy is demonstrated via direct electronic structure topology measurements using high resolution angle-resolved photoemission spectroscopy (ARPES). These results open up new opportunities for probing topological behavior of Dirac electrons on the Bi2Te3 surface. At least one of the methods demonstrated here can be successfully applied to other topological insulators such as the Bi{1-x}Sb{x}, Sb2Te3 and Bi2Se3 which will be shown elsewhere. More importantly, our methods of topological surface state manipulation demonstrated here are highly suitable for future spectroscopic studies of topological phenomena which will complement the transport results gained from the traditional electrical gating techniques.

4 Figures, 12 pages

Cited by in corpus (6)

• A topological insulator surface under strong Coulomb, magnetic and disorder perturbations
• Persistent Optical Gating of a Topological Insulator
• Discovery of several large families of Topological Insulator classes with backscattering-suppressed spin-polarized single-Dirac-cone on the surface
• Carrier doping of Bi${}_2$Se${}_3$ surface by chemical adsorption -- a DFT study
• Singular Effects of Spin-Flip Scattering on Gapped Dirac Fermions
• Topology behind topological insulators