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

Autor: Krutitsky, K. V., Larson, J., Lewenstein, M.
Rok vydání: 2009
Předmět:
Zdroj: Phys. Rev. A 82, 033618 (2010)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevA.82.033618
Popis: 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. Linear and modulational stability show that the soliton solutions are sensitive to small perturbations and, therefore, unstable. In general, their lifetimes differ for on-site and off-site modes. For the on-site modes, there are small areas between the Mott-insulator regions where the lifetime is very large, and in particular much larger than that for the off-site modes.
Comment: 10 pages, 12 figures
Databáze: arXiv