Anisotropic effect of warping on the lifetime broadening of topological surface states in angle-resolved photoemission from Bi${}_2$Te${}_3$

Abstract

We analyze the strong hexagonal warping of the Dirac cone of Bi${}_2$Te${}_3$ by angle-resolved photoemission. Along $\overline{\Gamma }$$\overline{\mathrm{M}}$, the dispersion deviates from a linear behavior meaning that the Dirac cone is warped outwards and not inwards. We show that this introduces an anisotropy in the lifetime broadening of the topological surface state which is larger along $\overline{\Gamma }$$\overline{\mathrm{K}}$. The result is not consistent with nesting. Based on the theoretically predicted behavior of the ground-state spin texture of a strongly warped Dirac cone, we propose spin-dependent scattering processes as explanation for the anisotropic scattering rates. These results could help paving the way for optimizing future spintronic devices using topological insulators and controlling surface-scattering processes via external gate voltages.

12 pages, 5 figures

References in corpus (6)

• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Coherent control of a single electron spin with electric fields
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Direct Measurement of the Out-of-Plane Spin Texture in the Dirac Cone Surface State of a Topological Insulator
• Angle-resolved photoemission spectroscopy of electron-doped cuprate superconductors: Isotropic electron-phonon coupling
• Photoemission induced gating of topological insulator

Cited by in corpus (7)

• Landau level spectroscopy of Bi${}_2$Te${}_3$
• Observation of antiphase coherent phonons in the warped Dirac cone of Bi${}_2$Te${}_3$
• Ultrafast Evolution of Bulk, Surface and Surface Resonance States in Photoexcited Bi${}_2$Te${}_3$
• Unidirectional valley-contrasting photo-current in strained transition metal dichalcogenide monolayers
• Observation of anisotropic Dirac cones in the topological material Ti2Te2P
• Topological layered n-type thermoelectrics based on bismuth telluride solid solutions
• Scanning tunneling spectroscopy of the surface states of Dirac fermions in thermoelectrics based on bismuth telluride