Controllable non-local interactions between dark solitons in dipolar condensates

TL;DR

This paper investigates how non-local dipolar interactions influence dark soliton behavior in Bose-Einstein condensates, revealing tunable interactions and novel bound states with soliton-like properties.

Contribution

It introduces a detailed analysis of non-local interactions between dark solitons in dipolar condensates and demonstrates tunable bound states arising from these interactions.

Findings

Non-local interactions can be tuned via dipole polarization.

Dark solitons form bound states that behave like solitons.

Elastic collisions occur away from instabilities.

Abstract

We study the family of static and moving dark solitons in quasi-one-dimensional dipolar Bose-Einstein condensates, exploring their modified form and interactions. The density dip of the soliton acts as a giant anti-dipole which adds a non-local contribution to the conventional local soliton-soliton interaction. We map out the stability diagram as a function of the strength and polarization direction of the atomic dipoles, identifying both roton and phonon instabilities. Away from these instabilities, the solitons collide elastically. Varying the polarization direction relative to the condensate axis enables tuning of this non-local interaction between repulsive and attractive; the latter case supports unusual dark soliton bound states. Remarkably, these bound states are themselves shown to behave like solitons, emerging unscathed from collisions with each other.