Abstract:
We employ a Bose-Einstein-condensate–based atom-optic kicked rotor to generate an asymmetrically localized momentum distribution that depends upon the initial velocity of the Bose-Einstein condensate. Asymmetric features are shown to arise from the early-time dynamics induced by the broken parity symmetry and asymptotically freeze as the dynamical localization stabilizes. The asymmetry in the momentum distribution critically depends upon the initial launch velocity and is sensitive to very small initial velocities (micromotion) of the Bose-Einstein condensate. We also perform a precise measurement of the micromotion. By utilizing the technique of measuring the early-time asymmetry of the momentum distribution, we report measurement of the micromotion down to 230±17µm/s.