Robust surface electronic properties of topological insulators: Bi2Te3 films grown by molecular beam epitaxy

TL;DR

This study demonstrates that the topological surface states of Bi2Te3 films remain stable and retain their Dirac-cone features even after exposure to atmosphere and surface cleaning, highlighting their robustness.

Contribution

The paper shows that Bi2Te3 topological insulator surfaces maintain their electronic properties after atmospheric exposure and cleaning, using optimized sputter-anneal procedures.

Findings

Dirac-cone features are preserved after surface treatment

Topological surface states are insensitive to surface roughness

Surface electronic properties are robust under various preparation steps

Abstract

The surface electronic properties of the important topological insulator Bi2Te3 are shown to be robust under an extended surface preparation procedure which includes exposure to atmosphere and subsequent cleaning and recrystallization by an optimized in-situ sputter-anneal procedure under ultra high vacuum conditions. Clear Dirac-cone features are displayed in high-resolution angle-resolved photoemission spectra from the resulting samples, indicating remarkable insensitivity of the topological surface state to cleaning-induced surface roughness.