Propagation of Raman-matched laser pulses through a Bose-Einstein condensate

We investigate the role of non-uniform spatial density profiles of trapped atomic Bose-Einstein condensates in the propagation of Raman-matched laser pulses under conditions for electromagnetically induced transparency (EIT). We find that the sharp edged axial density profile of an interacting condensate (due to a balance between external trap and repulsive atomic interaction) is advantageous for obtaining ultra slow averaged group velocities. Our results are in good quantitative agreement with a recent experiment report [Nature {\bf 397}, 594 (1999)].