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 4 pi epsilon(0) x 87.4 +/- 0.4 +/- 2.5 angstrom(3) and 4 pi epsilon(0) x 106.4 +/- 0.2 +/- 1.1 angstrom(3), respectively, in excellent agreement with previous deflection experiments, but with improved uncertainties.