Pulsating and persistent vector solitons in a Bose-Einstein condensate in a lattice upon phase separation instability

TL;DR

This paper investigates the dynamic behavior of dual-species Bose-Einstein condensates in optical lattices, revealing pulsating and persistent vector solitons resulting from phase separation instability.

Contribution

It introduces a numerical analysis of soliton dynamics in BECs, highlighting the emergence of pulsating and persistent solitons under different instability conditions.

Findings

Single unstable mode leads to pulsating soliton pairs.

Multiple unstable modes produce persistent soliton-antisoliton pairs.

Oscillating regimes prevent stable phase separation.

Abstract

We study numerically the outcome of the phase separation instability of a dual-species Bose-Einstein condensate in an optical lattice. When only one excitation mode is unstable a bound pair of a bright and dark soliton-like structures periodically appears and disappears, whereas for more than one unstable mode a persistent soliton-antisoliton pair develops. The oscillating soliton represents a regime where the two-species condensate neither remains phase-separated nor is dynamically stable.