Robust topological edge states at the perfect surface step edge of topological insulator ZrTe$_5$

TL;DR

This study uses scanning tunneling microscopy to reveal that ZrTe$_5$ exhibits topological edge states at surface step edges, with magnetic field effects indicating strong topological-bulk state interactions, highlighting its potential for future applications.

Contribution

It provides atomic-scale evidence that ZrTe$_5$ is a 2D topological insulator with magnetic field-induced edge state splitting, advancing understanding of topological surface states.

Findings

ZrTe$_5$ has an ~80 meV bulk bandgap with topological edge states.

Magnetic field induces energetic splitting and spatial separation of edge states.

Surface steps and large bandgap make ZrTe$_5$ promising for future devices.

Abstract

We report an atomic-scale characterization of ZrTe$_5$ by using scanning tunneling microscopy. We observe a bulk bandgap of ~80 meV with topological edge states at the step edge, and thus demonstrate ZrTe$_5$ is a two dimensional topological insulator. It is also found that an applied magnetic field induces energetic splitting and spatial separation of the topological edge states, which can be attributed to a strong link between the topological edge states and bulk topology. The perfect surface steps and relatively large bandgap make ZrTe$_5$ be a potential candidate for future fundamental studies and device applications.