Gap-Townes solitons and localized excitations in low-dimensional Bose-Einstein condensates in optical lattices

Journal Article · Thu Sep 15 00:00:00 EDT 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.72.033617· OSTI ID:20718605

Abdullaev, Fatkhulla Kh; Salerno, Mario ^[1]

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1. Dipartimento di Fisica 'E.R. Caianiello', Universita di Salerno, I-84081 Baronissi (Saudi Arabia), Italy, and Physical-Technical Institute of the Academy of Sciences, 700084, Tashkent-84, G.Mavlyanov str., 2-b (Uzbekistan)

We discuss localized ground states of Bose-Einstein condensates (BEC's) in optical lattices with attractive and repulsive three-body interactions in the framework of a quintic nonlinear Schroedinger equation which extends the Gross-Pitaevskii equation to the one-dimensional case. We use both a variational method and a self-consistent approach to show the existence of unstable localized excitations which are similar to Townes solitons of the cubic nonlinear Schroedinger equation in two dimensions. These solutions are shown to be located in the forbidden zones of the band structure, very close to the band edges, separating decaying states from stable localized ones (gap solitons) fully characterizing their delocalizing transition. In this context the usual gap solitons appear as a mechanism for arresting the collapse in low-dimensional BEC's in optical lattices with an attractive real three-body interaction. The influence of the imaginary part of the three-body interaction, leading to dissipative effects in gap solitons, and the effect of atoms feeding from the thermal cloud are also discussed. These results may be of interest for both BEC's in atomic chips and Tonks-Girardeau gas in optical lattices.

• OSTI ID: 20718605
• Journal Information: Physical Review. A, Vol. 72, Issue 3; Other Information: DOI: 10.1103/PhysRevA.72.033617; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSE-EINSTEIN CONDENSATION
COOLING
EXCITATION
EXCITED STATES
GROUND STATES
LASER RADIATION
MATHEMATICAL SOLUTIONS
NONLINEAR PROBLEMS
ONE-DIMENSIONAL CALCULATIONS
SCHROEDINGER EQUATION
SOLITONS
THREE-BODY PROBLEM
VARIATIONAL METHODS