Band engineering of Dirac surface states in topological insulators-based van der Waals heterostructures

TL;DR

This paper demonstrates that surface band structures of 3D topological insulators can be engineered through surface modifications in van der Waals heterostructures, enabling independent control of surface and bulk electronic properties for advanced device design.

Contribution

It introduces a novel method to modify Dirac surface states in 3D topological insulators via surface engineering without losing their topological properties.

Findings

Surface modifications can tune Dirac surface states.

Surface and bulk electronic structures can be independently controlled.

Method applicable to designing artificial topological materials.

Abstract

The existence of gapless Dirac surface band of a three dimensional (3D) topological insulator (TI) is guaranteed by the non-trivial topological character of the bulk band, yet the surface band dispersion is mainly determined by the environment near the surface. In this Letter, through in-situ angle-resolved photoemission spectroscopy (ARPES) and the first-principles calculation on 3D TI-based van der Waals heterostructures, we demonstrate that one can engineer the surface band structures of 3D TIs by surface modifications without destroying their topological non-trivial property. The result provides an accessible method to independently control the surface and bulk electronic structures of 3D TIs, and sheds lights in designing artificial topological materials for electronic and spintronic purposes.