Control Of Ultracold Collisional Processes With Frequency-Chirped Light

Phillip L. Gould
University of Connecticut

Control of Ultracold Collisional Processes with Frequency - Chirped Light

It is well known that collisional interactions between ultracold atoms can be dramatically affected by near-resonant laser light. I will described experiments in which we take advantage of the slow nature of the collision dynamics to control trap-loss collisions with frequency-chirped light on the nanosecond time scale. In general, we see a large transient collisional loss rate cause by efficient adiabatic excitation of atom pairs to a long-range attractive molecular potential. Of particular interest is the dramatic dependence of collisional loss rate on chirp direction. As the center detuning of the chirp is varied, the loss rate for the negative chirp can be either enhanced or suppressed relative to that for the positive chirp. We attribute this to the multiple, in some cases coherent, interactions between the colliding pair and the chirped light as the negative chirp "follows" the resonance condition of the converging atom pair.