Multi-mode description of an interacting Bose-Einstein condensate.
We study the equilibrium dynamics of a weakly interacting Bose-Einstein condensate trapped in a box. In our approach we use a semiclassical approximation similar to the description of a multi-mode laser. In dynamical equations derived from a full N-body quantum Hamiltonian we substitute all creation (and annihilation) operators (of a particle in a given box state) by appropriate c-number amplitudes. The set of nonlinear equations obtained in this way is solved numerically. We show that on the time scale of a few miliseconds the system exhibits relaxation -- reaches an equilibrium with populations of different eigenstates fluctuating around their mean values.
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K
Goral
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M
Gajda
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K
Rzazewski