Gapped Electronic Structure of Epitaxial Stanene on InSb(111)

TL;DR

This study demonstrates that epitaxial stanene grown on InSb(111) exhibits a sizable electronic gap of 0.44 eV, making it a promising candidate for room-temperature quantum spin Hall effect applications.

Contribution

First experimental demonstration of a large band gap in epitaxial stanene on InSb(111), supported by theoretical calculations.

Findings

ARPES measurements show a 0.44 eV gap in stanene on InSb(111)

First-principles calculations confirm the experimental gap

Stanene on InSb(111) is suitable for room-temperature QSH devices

Abstract

Stanene (single-layer grey tin), with an electronic structure akin to that of graphene but exhibiting a much larger spin-orbit gap, offers a promising platform for room-temperature electronics based on the quantum spin Hall (QSH) effect. This material has received much theoretical attention, but a suitable substrate for stanene growth that results in an overall gapped electronic structure has been elusive; a sizable gap is necessary for room-temperature applications. Here, we report a study of stanene epitaxially grown on the (111)B-face of indium antimonide (InSb). Angle-resolved photoemission spectroscopy (ARPES) measurements reveal a gap of 0.44 eV, in agreement with our first-principles calculations. The results indicate that stanene on InSb(111) is a strong contender for electronic QSH applications.