# Spectroscopy and Directed Transport of Topological Solitons in Crystals of Trapped Ions

## TL;DR

This study investigates the behavior of topological solitons in laser-cooled ion crystals, demonstrating control over their dynamics and transport through external excitation and trapping potentials, with implications for nonlinear physics.

## Contribution

It provides experimental and theoretical insights into soliton excitation, control, and transport in ion crystals, highlighting a thermal activation mechanism and topological charge-dependent directed motion.

## Key findings

- Solitons can be excited and stabilized in ion crystals.
- Soliton transport can be controlled via external excitation amplitude.
- Directed transport depends on the soliton's topological charge.

## Abstract

We study experimentally and theoretically discrete solitons in crystalline structures consisting of several tens of laser-cooled ions confined in a radiofrequency trap. Resonantly exciting localized, spectrally gapped vibrational modes of the soliton, a nonlinear mechanism leads to a nonequilibrium steady state of the continuously cooled crystal. We find that the propagation and the escape of the soliton out of its a quasi-one-dimensional channel can be described as a thermal activation mechanism. We control the effective temperature of the soliton's collective coordinate by the amplitude of the external excitation. Furthermore, the global trapping potential permits controlling the soliton dynamics and realizing directed transport depending on its topological charge.