Description of Experiment

In the experiments that inspired this work [1,2,3], Rubidium atoms in the 23s and 33s states are trapped and laser cooled until their translational motion is sufficiently reduced that they can be assumed to be frozen in place. These atoms are then allowed to interact with each other for a short time, typically 5 µs. During this time the processes ss'pp' and spps can occur via dipole-dipole interactions, where s, s', p, and p' represent the 23s, 33s, 24p, and 34p states, respectively. The spps process is always resonant, but classically the ss'pp' process can only occur when the detuning is equal to zero. Quantum mechanically, the ss'pp' process is more likely to occur when , but can still take place away from resonance, albeit with a reduced probability. In the experiment the number of p' atoms is measured as a function of time, and as a function of the detuning .