We demonstrate an exact Talbot effect based on the dispersion relation of matter waves. A short-pulse, optical standing wave is used to write a phase grating on a sodium condensate and a second, identical diffraction pulse is applied after a variable delay to analyze the temporal evolution of the resulting wavefunction. We show that the effect of a second pulse at integer multiples of the 10 υs Talbot time is identical to that of a single pulse of twice the duration of the first. When the second pulse is applied at odd multiples of half the Talbot time, it cancels the effect of the first pulse. Intermediate delays produce more complicated momentum-space patterns that are in excellent agreement with theory. The crucial differences between short-pulse phase gratings and static amplitude or static phase gratings are discussed.
Citation: Physical Review Letters
Issue: No. 26
Pub Type: Journals
matter wave dispersion, Talbot effect