Experimental observation of dynamical localization and decoherence in the atomic -kicked rotor

We experimentally investigate decoherence by spontaneous emission in the quantum delta kicked rotor. Caesium atoms in a magneto-optic trap are initially cooled, and then subjected to a pulsed standing wave of near resonant light. As the detuning from the atomic transition is varied, we observe a change in the momentum diffusion after the quantum break time.