Decay of molecules at spherical surfaces: Nonlocal effects

The decay rates for molecules in the vicinity of a metallic sphere are investigated in a phenomenological approach for very close molecule-surface distances d. The Fuchs-Claro model [Phys. Rev. B 35, 3722 (1987)] is adopted to describe the polarizability of the sphere with the nonlocal dielectric response being accounted for within the hydrodynamic description. The results show significant differences when compared with those obtained previously within a local description for d≲50 Å, with extra resonances observed in the high-frequency regime, a phenomenon similar to that noted previously by Ruppin in his calculation of the extinction cross section for such spheres.