Polarizability measurements in a molecule near-field interferometer

We apply near-field matter-wave interferometry to determine the absolute scalar polarizability of the fullerenes C$_{60}$ and C$_{70}$. A key feature of our experiment is the combination of good transmission and high spatial resolution, gained by wide molecular beams passing through sub-micron gratings. This allows to significantly facilitate the observation of field-dependent beam shifts. We thus measure the polarizability to be $\alpha=88.9 \pm 0.9 \pm 5.1 \rm \AA^{3}$ for C$_{60}$ and to $\alpha = 108.5 \pm 2.0 \pm 6.2 \rm \AA^{3}$ for C$_{70}$.