Emergence of topological bands on the surface of ZrSnTe crystal

TL;DR

This study reveals that the surface of ZrSnTe crystals hosts topological insulator states with tunable electronic properties, achieved through surface hydrogenation, which could advance applications in topological devices.

Contribution

The paper demonstrates the emergence of 2D topological insulator bands on ZrSnTe surfaces and shows how surface modification can control their electronic properties.

Findings

2D topological insulator bands are present on ZrSnTe surface.

Hydrogenation modifies surface states to potentially open a global energy gap.

Findings suggest ZrSnTe as a candidate for topological device applications.

Abstract

By using angle-resolved photoemission spectroscopy combined with first-principles calculations, we reveal that the topmost unit cell of ZrSnTe crystal hosts two-dimensional (2D) electronic bands of topological insulator (TI) state, though such a TI state is defined with a curved Fermi level instead of a global band gap. Furthermore, we find that by modifying the dangling bonds on the surface through hydrogenation, this 2D band structure can be manipulated so that the expected global energy gap is most likely to be realized. This facilitates the practical applications of 2D TI in heterostructural devices and those with surface decoration and coverage. Since ZrSnTe belongs to a large family of compounds having the similar crystal and band structures, our findings shed light on identifying more 2D TI candidates and superconductor-TI heterojunctions supporting topological superconductors.