SENSITIVE RESPONSE OF A 2-LEVEL ATOM TO A VERY WEAK SQUEEZED VACUUM

We report the extreme sensitivity of the resonance fluorescence spectr a of a two level atom interacting with a detuned classical field to th e presence of a very weak squeezed vacuum (which includes a black body field as a special case). Large asymmetries are induced by these very weak perturbations. For an appropriate choice of squeezing phase, a p ronounced minimum is found in one of the peaks as the intensity of the squeezed field increases. The connection with population trapping in squeezed fields is established, and a physical interpretation provided .