We study experimentally superradiance in a Bose-Einstein condensate using a two-frequency pump beam. By controlling the frequency difference between the beam components, we measure the spectrum of the backward (energy-mismatched) superradiant atomic modes. In addition, we show that the populations of these modes display coherent time-dynamics. These results are compared to a semi-classical model based on coupled Schroedinger-Maxwell equations.
@article{arxiv.0705.2518,
title = {Spectroscopy of Strong-Pulse Superradiance in a Bose-Einstein condensate},
author = {Nir Bar-Gill and Eitan E. Rowen and Nir Davidson},
journal= {arXiv preprint arXiv:0705.2518},
year = {2009}
}