Two-dimensional discrete solitons in dipolar Bose-Einstein condensates

Journal Article · Fri Jan 15 00:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.013633· OSTI ID:21388795

Gligoric, Goran; Stepic, Milutin; Hadzievski, Ljupco ^[1]; Maluckov, Aleksandra ^[2]; Malomed, Boris A ^[3]

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1. Vinca Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia)
2. Faculty of Sciences and Mathematics, University of Nis, P.O. Box 224, 18001 Nis (Serbia)
3. Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

We analyze the formation and dynamics of bright unstaggered solitons in the disk-shaped dipolar Bose-Einstein condensate, which features the interplay of contact (collisional) and long-range dipole-dipole (DD) interactions between atoms. The condensate is assumed to be trapped in a strong optical-lattice potential in the disk's plane, hence it may be approximated by a two-dimensional (2D) discrete model, which includes the on-site nonlinearity and cubic long-range (DD) interactions between sites of the lattice. We consider two such models, which differ by the form of the on-site nonlinearity, represented by the usual cubic term, or more accurate nonpolynomial one, derived from the underlying three-dimensional Gross-Pitaevskii equation. Similar results are obtained for both models. The analysis is focused on the effects of the DD interaction on fundamental localized modes in the lattice (2D discrete solitons). The repulsive isotropic DD nonlinearity extends the existence and stability regions of the fundamental solitons. New families of on-site, inter-site, and hybrid solitons, built on top of a finite background, are found as a result of the interplay of the isotropic repulsive DD interaction and attractive contact nonlinearity. By themselves, these solutions are unstable, but they evolve into robust breathers which exist on an oscillating background. In the presence of the repulsive contact interactions, fundamental localized modes exist if the DD interaction (attractive isotropic or anisotropic) is strong enough. They are stable in narrow regions close to the anticontinuum limit, while unstable solitons evolve into breathers. In the latter case, the presence of the background is immaterial.

• OSTI ID: 21388795
• Journal Information: Physical Review. A, Vol. 81, Issue 1; Other Information: DOI: 10.1103/PhysRevA.81.013633; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
BOSE-EINSTEIN CONDENSATION
DIPOLES
EQUATIONS
HYBRIDIZATION
INTERACTIONS
MATHEMATICAL SOLUTIONS
NONLINEAR PROBLEMS
POTENTIALS
SOLITONS
STABILITY
THREE-DIMENSIONAL CALCULATIONS
TRAPPING
TWO-DIMENSIONAL CALCULATIONS
MULTIPOLES
QUASI PARTICLES