# Impurity and soliton dynamics in a Fermi gas with nearest-neighbor interactions

## TL;DR

This paper investigates how impurities and local quenches affect soliton-antisoliton pair formation and dynamics in a one-dimensional Fermi gas with nearest-neighbor interactions, combining numerical and analytical approaches.

## Contribution

It introduces a combined numerical and analytical study of impurity-induced soliton dynamics in a Fermi gas with nearest-neighbor interactions, revealing novel confinement phenomena.

## Key findings

- Impurities induce soliton-antisoliton pairs in the Fermi gas.
- Antisolitons can become confined near their origin due to existing solitons.
- The dynamics differ significantly depending on the initial soliton presence.

## Abstract

We study spinless fermions with repulsive nearest-neighbor interactions perturbed by an impurity particle or a local potential quench. Using the numerical time-evolving block decimation method and a simplified analytic model, we show that the pertubations create a soliton-antisoliton pair. If solitons are already present in the bath, the two excitations have a drastically different dynamics: The antisoliton does not annihilate with the solitons and is therefore confined close to its origin while the soliton excitation propagates. We discuss the consequences for experiments with ultracold gases.