Coulomb screening in mesoscopic noise: a kinetic approach

Coulomb screening, together with degeneracy, is characteristic of the metal lic electron gas. While there is little trace of its effects in transport a nd noise in the bulk, at mesoscopic scales the electronic fluctuations star t to show appreciable Coulomb correlations. Within completely standard Bolt zmann and Fermi-liquid frameworks, we analyse these phenomena and their rel ation to the mesoscopic fluctuation-dissipation theorem, which we prove. We identify two distinct screening mechanisms for mesoscopic fluctuations. On e is the self-consistent response of the contact potential in a non-uniform system. The other couples to scattering, and is an exclusively non-equilib rium process. Contact-potential effects renormalize all thermal fluctuation s, at all scales. Collisional effects are relatively short ranged and modif y non-equilibrium noise. We discuss ways to detect these differences experi mentally.