Improved accuracy fullerene polarizability measurements in a long-baseline matter-wave interferometer

We present electric deflection results for the fullerenes C_{60} and C_{70} obtained with a long-baseline matter-wave interferometer. The second grating of the interferometer is interchangeable between a material grating for fast atom beams and an optical phase grating for polarizable molecules. This allows us to use cesium as a calibration particle and thus measure molecular susceptibilities with improved systematic uncertainty. The static polarizabilities of C_{60} and C_{70} are measured as 4πɛ_{0}×87.4±0.4±2.5Å^{3} and 4πɛ_{0}×106.4±0.2±1.1Å^{3}, respectively, in excellent agreement with previous deflection experiments, but with improved uncertainties.