Atomic Wave Diffraction and Interference Using Temporal Slits

We measure the energy distribution of a slow Cesium atomic beam when it is chopped into a short pulse and we find results which agree well with the time-energy uncertainty principle. The chopper consists in an atomic mirror formed by a laser evanescent wave whose intensity is pulsed. We use the temporally diffracted beam to design a Young-slit-type interferometer, in which the interfering paths consist of atomic trajectories bouncing at two different times on the mirror. By changing the mirror intensity, we can scan the atomic phase difference between the two arms.