Dark solitons near the Mott-insulator--superfluid phase transition

Understand

Dark solitons of ultracold bosons in the vicinity of the Mott-insulator--superfluid phase transition are studied.

• Making use of the Gutzwiller ansatz we have found antisymmetric eigenstates corresponding to standing solitons, as well as propagating solitons created by phase imprinting.
• Near the phase boundary, superfluidity has either a particle or a hole character depending on the system parameters, which greatly affects the characteristics of both types of solitons.
• Within the insulating Mott regions, soliton solutions are prohibited by lack of phase coherence between the lattice sites.