Bose-Einstein condensates under a spatially modulated transverse confinement

Journal Article · Sun Jul 15 00:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.76.013623· OSTI ID:21011292

Salasnich, L; Toigo, F ^[1]; Cetoli, A ^[2]; Malomed, B A ^[3]; Reatto, L ^[4]

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1. CNISM and CNR-INFM, Unita di Padova, Via Marzolo 8, 35131 Padova (Italy)
2. Dipartimento di Fisica 'Galileo Galilei', Universita di Padova, Via Marzolo 8, 35131 Padova (Italy)
3. Department of Interdisciplinary Studies, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)
4. Dipartimento di Fisica and CNISM, Universita di Milano, Via Celoria 16, 20133 Milan (Italy)

We derive an effective nonpolynomial Schroedinger equation (NPSE) for self-repulsive or attractive BEC in the nearly one-dimensional cigar-shaped trap, with the transverse confining frequency periodically modulated along the axial direction. In addition to the usual linear cigar-shaped trap, where the periodic modulation emulates the action of an optical lattice (OL), the model may be also relevant to toroidal traps, where an ordinary OL cannot be created. For either sign of the nonlinearity, extended and localized states are found, in the numerical form [using both the effective NPSE and the full three-dimensional (3D) Gross-Pitaevskii equation] and by means of the variational approximation (VA). The latter is applied to construct ground-state solitons and predict the collapse threshold in the case of self-attraction. It is shown that numerical solutions provided by the one-dimensional NPSE are always very close to full 3D solutions, and the VA yields quite reasonable results too. The transition from delocalized states to gap solitons, in the first finite bandgap of the linear spectrum, is examined in detail, for the repulsive and attractive nonlinearities alike.

• OSTI ID: 21011292
• Journal Information: Physical Review. A, Vol. 76, Issue 1; Other Information: DOI: 10.1103/PhysRevA.76.013623; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
BOSE-EINSTEIN CONDENSATION
GROUND STATES
MODULATION
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
ONE-DIMENSIONAL CALCULATIONS
PERIODICITY
SCHROEDINGER EQUATION
SOLITONS
SPECTRA
THREE-DIMENSIONAL CALCULATIONS
TRAPS
VARIATIONAL METHODS