# Core filling and snaking instability of dark solitons in spin-imbalanced superfluid Fermi gases

## TL;DR

This paper investigates how unpaired spins in spin-imbalanced superfluid Fermi gases affect dark solitons, revealing core filling effects and suppression of snake instability through time-dependent Bogoliubov de Gennes simulations.

## Contribution

It demonstrates the impact of spin imbalance on dark soliton stability and shape, highlighting the role of unpaired particles in core filling and instability suppression.

## Key findings

- Unpaired spins fill the soliton cores, broadening them.
- Spin imbalance suppresses the transverse snake instability.
- Potential experimental observation in cold atom systems.

## Abstract

We use the time-dependent Bogoliubov de Gennes equations to study dark solitons in three-dimensional spin-imbalanced superfluid Fermi gases. We explore how the shape and dynamics of dark solitons are altered by the presence of excess unpaired spins which fill their low-density core. The unpaired particles broaden the solitons and suppress the transverse snake instability. We discuss ways of observing these phenomena in cold atom experiments.