Many-body Matter-wave Dark Soliton

The Gross-Pitaevskii equation - which describes interacting bosons in the mean-field approximation - possesses solitonic solutions in dimension one. For repulsively interacting particles, the stationary soliton is dark, i.e. is represented by a local density minimum. Many-body effects may lead to filling of the dark soliton. Using quasi-exact many-body simulations, we show that, in single realizations, the soliton appears totally dark although the single particle density tends to be uniform.