Dark solitons and their head-on collisions in Bose-Einstein condensates

Abstract

The evolution and collision of dark solitary waves (solitons) appearing in cigar-shaped Bose-Einstein condensates with repulsive atom-atom interaction are here considered using a Boussinesq-Korteweg--de Vries description. We provide theoretical predictions and computer experiment evidence about their phase shifts or change of trajectories, in the space-time plot, corresponding upon collisions. Details are also given about a suggested experiment that could assess their genuine solitonic nature.