# Spontaneous generation of dark-bright and dark-antidark solitons upon quenching a particle-imbalanced bosonic mixture

## TL;DR

This paper investigates how quenching a particle-imbalanced Bose-Bose mixture leads to the spontaneous formation of dark-bright and dark-antidark solitons, revealing the mechanisms, control parameters, and robustness of these localized structures.

## Contribution

It uncovers the dynamical generation mechanisms of dark-bright and dark-antidark solitons during interaction quenches in imbalanced Bose mixtures, including effects of particle imbalance and trap geometry.

## Key findings

- More solitons form with larger particle imbalance.
- Stronger postquench interactions increase soliton number.
- Tighter traps suppress soliton formation.

## Abstract

We unveil the dynamical formation of multiple localized structures in the form of dark-bright and dark-antidark solitary waves that emerge upon quenching a one-dimensional particle-imbalanced Bose-Bose mixture. Interspecies interaction quenches drive the system out-of-equilibrium while the so-called miscible/immiscible threshold is crossed in a two directional manner. Dark-bright entities are spontaneously generated for quenches towards the phase separated regime and dark-antidark states are formed in the reverse process. The distinct mechanisms of creation of the aforementioned states are discussed in detail and their controlled generation is showcased. In both processes, it is found that the number of solitary waves generated is larger for larger particle imbalances, a result that is enhanced for stronger postquench interspecies interactions. Additionally the confining geometry highly affects the production of both types of states with a decaying solitary wave formation occurring for tighter traps. Furthermore, in both of the aforementioned transitions, the breathing frequencies measured for the species differ significantly for highly imbalanced mixtures. Finally, the robustness of the dynamical formation of dark-bright and dark-antidark solitons is also demonstrated in quasi one-dimensional setups.