Conductivity of a small metallic particle



The size-dependent ac-conductivity of a small metallic particle is studied for electrons enclosed in a box with random impurities. The exact wave functions and energies are calculated numerically up to 500 electrons, then the Kubo-formula is evaluated, and an ensemble average is performed. A strong size- and frequency dependence of the conductivity is found which is in good agreement with random matrix results. The size dependence of the dc-conductivity agrees qualitatively with microwave absorption measurements on submicron particles.