Three-dimensional solitons in coupled atomic-molecular Bose-Einstein condensates

Journal Article · Wed Dec 01 04:00:00 EST 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.70.063611· OSTI ID:20649981

Vaughan, T G; Kheruntsyan, K V; Drummond, P D ^[1]

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1. ARC Centre of Excellence for Quantum-Atom Optics, School of Physical Sciences, University of Queensland, Brisbane, Queensland 4072 (Australia)

We present a theoretical analysis of three-dimensional (3D) matter-wave solitons and their stability properties in coupled atomic and molecular Bose-Einstein condensates (BECs). The soliton solutions to the mean-field equations are obtained in an approximate analytical form by means of a variational approach. We investigate soliton stability within the parameter space described by the atom-molecule conversion coupling, the atom-atom s-wave scattering, and the bare formation energy of the molecular species. In terms of ordinary optics, this is analogous to the process of sub- or second-harmonic generation in a quadratic nonlinear medium modified by a cubic nonlinearity, together with a phase mismatch term between the fields. While the possibility of formation of multidimensional spatiotemporal solitons in pure quadratic media has been theoretically demonstrated previously, here we extend this prediction to matter-wave interactions in BEC systems where higher-order nonlinear processes due to interparticle collisions are unavoidable and may not be neglected. The stability of the solitons predicted for repulsive atom-atom interactions is investigated by direct numerical simulations of the equations of motion in a full 3D lattice. Our analysis also leads to a possible technique for demonstrating the ground state of the Schroedinger-Newton and related equations that describe Bose-Einstein condensates with nonlocal interparticle forces.

• OSTI ID: 20649981
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 70; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
ATOMS
BOSE-EINSTEIN CONDENSATION
COMPUTERIZED SIMULATION
CONVERSION
COUPLING
EQUATIONS OF MOTION
GROUND STATES
HARMONIC GENERATION
MATHEMATICAL SOLUTIONS
MEAN-FIELD THEORY
MOLECULES
NONLINEAR PROBLEMS
NUMERICAL ANALYSIS
S WAVES
SCATTERING
SOLITONS
STABILITY
THREE-DIMENSIONAL CALCULATIONS
VARIATIONAL METHODS