Cold atoms: A new medium for quantum optics
  Laser-cooled and trapped cesium atoms have been used as a nonlinear medium in a nearly resonant cavity. A study of the semiclassical dynamics of the system was performed, showing bistability and instabilities. In the quantum domain, squeezing in a probe beam having interacted with this system was demonstrated. 
A. Lambrecht, J.M. Courty, S. Reynaud, E. Giacobino