Robust topological insulator surface state in MBE grown (Bi_{1-x}Sb_x)_2Se_3

TL;DR

This paper reports the successful growth and characterization of (Bi_{1-x}Sb_x)_2Se_3 thin films, demonstrating robust topological surface states and tunable transport properties, including a transition to an insulating phase at specific doping levels.

Contribution

It provides experimental evidence of robust topological surface states in MBE-grown (Bi_{1-x}Sb_x)_2Se_3 and shows tunability of transport properties via Sb doping.

Findings

Robust topological surface states confirmed by ARPES and transport measurements.

Tunable transport properties with Sb doping, including an insulating phase at x=0.5.

Potential for device applications based on tunable topological insulators.

Abstract

(Bi1-xSbx)2Se3 thin films have been prepared using molecular beam epitaxy (MBE). We demonstrate the angle-resolved photoemission spectroscopy (ARPES) and transport evidence for the existence of strong and robust topological surface states in this ternary system. Large tunability in transport properties by varying the Sb doping level has also been observed, where insulating phase could be achieved at x=0.5. Our results reveal the potential of this system for the study of tunable topological insulator and metal-insulator transition based device physics.