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

Shrestha, Uttam and Javanainen, Juha and Ruostekoski, Janne (2009) Pulsating and persistent vector solitons in a Bose-Einstein condensate in a lattice upon phase separation instability. Physical review letters, 103 (19). ISSN 1079-7114

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 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.