Phys.org  September 9, 2024 Because of the quantum nature of electrons, real interfaces have finite thickness, leading to nonclassical surface effects that influence light scattering in small particles. Electrical gating offers a promising route to control and study these effects, as static screening charges reside at the boundary. An international team of researchers (Germany, Denmark) investigated the modulation of the surface response upon direct electrical charging of single plasmonic nanoresonators. By analyzing measured changes in light scattering within the framework of surface response functions, they found the resonance shift well accounted for by modulation of the classical in-plane surface current. […]