Elemental Topological Insulator with a Tunable Fermi Level: Strained \alpha-Sn on InSb(001)

TL;DR

This paper reports the epitaxial growth and electronic characterization of a topological phase in strained -Sn on InSb(001), revealing a unique band order and tunable Fermi level, advancing topological insulator research.

Contribution

It demonstrates the fabrication of a topological phase in strained -Sn with a novel band order and controllable Fermi level, supported by experimental and theoretical analysis.

Findings

Topological surface state forms in strained -Sn on InSb.

Fermi level can be precisely tuned by dopants.

Unique band order not based on direct spin-orbit coupling.

Abstract

We report on the epitaxial fabrication and electronic properties of a topological phase in strained \alpha-Sn on InSb. The topological surface state forms in the presence of an unusual band order not based on direct spin-orbit coupling, as shown in density functional and GW slab-layer calculations. Angle-resolved photoemission including spin detection probes experimentally how the topological spin-polarized state emerges from the second bulk valence band. Moreover, we demonstrate the precise control of the Fermi level by dopants.