Realistic model for a quantum reflection trap

We examine the possibility of trapping ultra-cold atoms solely by quantum reflection in front of the walls of a cavity. Using a model potential with realistic threshold properties, we calculate the enhancement of the survival probability in the trap compared to the decay of a freely spreading wave-packet. Under conditions close to a recent experiment [T.A. Pasquini, Y. Shin, C. Sanner, M. Saba, A. Schirotzek, D.E. Pritchard, W. Ketterle, Phys. Rev. Lett. 93 (2004) 223201], an enhancement factor near 100 and surviving fractions of 10–20% are obtained after a time of 0.4 s.