Generic model of an atom laser
  We present a generic model of an atom laser by including a pump and loss term in the Gross-Pitaevskii equation. We show that there exists a threshold for the pump above which the mean matter field assumes a non-vanishing value in steady-state. We study the transient regime of this atom laser and find oscillations around the stationary solution even in the presence of a loss term. These oscillations are damped away when we introduce a position dependent loss term. For this case we present a modified Thomas-Fermi solution that takes into account the pump and loss. Our generic model of an atom laser is analogous to the semi-classical theory of the laser. 
B. Kneer (1), T. Wong (2), K. Vogel (1), W. P. Schleich (1), D. F.   Walls (2) ((1) Universitaet Ulm, Germany, (2) Universit...