Nonlocal Response of Metallic Nanospheres Probed by Light, Electrons, and Atoms

Inspired by recent measurements on individual metallic nanospheres that can not be explained with traditional classical electrodynamics, we theoretically investigate the effects of nonlocal response by metallic nanospheres in three distinct settings: atomic spontaneous emission, electron energy loss spectroscopy, and light scattering. These constitute two near-field and one far-field measurements, with zero-, one-, and two-dimensional excitation sources, respectively. We search for the clearest signatures of hydrodynamic pressure waves in nanospheres. We employ a linearized hydrodynamic model and Mie–Lorenz theory is applied for each case. Nonlocal response shows its mark in all three configurations, but ∗To whom correspondence should be addresse