In collaboration with our theory colleagues from Paris (M. Lepers, J.-F. Wyart and O. Dulieu) we have determined the dynamical polarizability of ultracold erbium atoms in the ground and in one excited state at three particular relevant wavelengths.
We observe a very good overall agreement between experimental measurements of the light shift and theoretical calculations. Our results isolates the isotropic and anisotropic contributions to the polarizability, which paves the way for spin-selective preparation and manipulation.