# Topological insulator particles as optically induced oscillators: towards dynamical force measurements and optical rheology

## TL;DR

This study demonstrates that topological insulator particles can be optically trapped and made to oscillate, functioning as optically induced oscillators for potential applications in dynamical force measurements and optical rheology.

## Contribution

First experimental demonstration of optical trapping and oscillation of topological insulator particles, revealing their potential as optically controlled oscillators.

## Key findings

- TI particles oscillate perpendicularly to laser propagation due to radiation and gradient forces.
- TI particles can be used for dynamical force measurements and optical rheology.
- Optical control of TI particles enables new experimental possibilities.

## Abstract

We report the first experimental study upon the optical trapping and manipulation of topological insulator (TI) particles. By virtue of the unique TI properties, which have a conducting surface and an insulating bulk, the particles present a peculiar behaviour in the presence of a single laser beam optical tweezers: they oscillate in a plane perpendicular to the direction of the laser propagation, as a result of the competition between radiation pressure and gradient forces. In other words, TI particles behave as optically induced oscillators, allowing dynamical measurements with unprecedented simplicity and purely optical control. Actually, optical rheology of soft matter interfaces and biological membranes, as well as dynamical force measurements in macromolecules and biopolymers, may be quoted as feasible possibilities for the near future.