A Kapitza-Dirac-Talbot-Lau interferometer for highly polarizable molecules

Research on matter waves is a thriving field of quantum physics and has recently stimulated many investigations with electrons(1), neutrons(2), atoms(3), Bose-condensed ensembles(4), cold clusters(5) and hot molecules(6). Coherence experiments with complex objects are of interest for exploring the transition to classical physics(7-9), for measuring molecular properties(10), and they have even been proposed for testing new models of space-time(11). For matter-wave experiments with complex molecules, the strongly dispersive effect of the interaction between the diffracted molecule and the grating wall is a major challenge because it imposes enormous constraints on the velocity selection of the molecular beam(12). Here, we describe the first experimental realization of a new set-up that solves this problem by combining the advantages of a so-called Talbot-Lau interferometer(13) with the benefits of an optical phase grating.