# Joule meets van der Waals: Mechanical dissipation via image potential states on a topological insulator surface

## TL;DR

This study reveals a new dissipation mechanism on topological insulator surfaces involving electron tunneling into image potential states, which is suppressed by topological protection and restored by magnetic fields, offering insights into quantum surface phenomena.

## Contribution

It demonstrates a novel dissipation process linked to quantum tunneling into image potential states on topological insulators, measured via nanomechanical AFM.

## Key findings

- Suppressed Joule dissipation due to topological protection.
- Observation of dissipation from electron tunneling into image potential states.
- Magnetic field restores Joule dissipation by breaking topological protection.

## Abstract

Dissipation mechanisms are experimentally studied on topological insulator surfaces of Bi2Te3, where common Joule dissipation was observed to be suppressed due to topologically protected surface states. Thus, a novel type of dissipation mechanism is observed by pendulum AFM, which is related to single electron tunneling resonances into image potential states that are slightly above the Bi2Te3 surface. The application of a magnetic field leads to the break down of the topological protection of the surface states and restores the expected Joule dissipation process. Nanomechanical energy dissipation experienced by the cantilever of pendulum AFM provides a novel source of information on the dissipative nature of the quantum-tunneling phenomena on the topological insulator surface.