Matter-wave interferometer for large molecules.

We demonstrate a near-field Talbot-Lau interferometer for ${\mathrm{C}}_{70}$ fullerene molecules. Such interferometers are particularly suitable for larger masses. Using three free-standing gold gratings of $1\ensuremath{\mu}\mathrm{m}$ period and a transversally incoherent but velocity-selected molecular beam, we achieve an interference fringe visibility of $40%$ with high count rate. Both the high visibility and its velocity dependence are in good agreement with a quantum simulation that takes into account the van der Waals interaction of the molecules with the gratings and are in striking contrast to a classical moir\'e model.