Reversible tuning of the surface state in a psuedo-binary Bi2(Te-Se)3 topological insulator

TL;DR

This study investigates the surface states of a psuedo-binary Bi2(Te-Se)3 topological insulator using ARPES, revealing its intrinsic topological nature and demonstrating reversible tuning of its surface properties through UV-assisted hydrogen absorption.

Contribution

It introduces a method to reversibly tune the surface state of a psuedo-binary topological insulator via UV-assisted hydrogen absorption, highlighting its potential for device applications.

Findings

The material is an intrinsic topological insulator with conduction band above the chemical potential.

Surface state shifts are caused by UV-assisted hydrogen absorption.

No significant aging effects observed over two weeks after cleaving.

Abstract

We use angle-resolved photoemission spectroscopy to study non-trivial surface state in psuedobinary Bi2Se0.6Te2.3 topological insulator. We show that unlike previously studied binaries, this is an intrinsic topological insulator with conduction bulk band residing well above the chemical potential. Our data indicates that under good vacuum condition there are no significant aging effects for more then two weeks after cleaving. We also demonstrate that shift of the Kramers point at low temperature is caused by UV assisted absorption of molecular hydrogen. Our findings pave the way for applications of these materials in devices and present an easy scheme to tune their properties.