ELASTIC AND INELASTIC-SCATTERING IN QUANTUM DOTS IN THE COULOMB-BLOCKADE REGIME

Starting from a rate-equation model proposed by Beenakker, we calculat e current-voltage characteristics for symmetric and asymmetric vertica l quantum dots. We include up to 26 electrons and show how single-elec tron charge interaction, inelastic scattering, and nonadiabatic subban d mixing can enhance the valley current significantly by opening new c onduction channels. Subband mixing is the dominant mechanism increasin g the valley current in both symmetric and asymmetric quantum dots. Si ngle-electron charging is important in asymmetric structures but relat ively weak in symmetric structures. Effects of inelastic scattering wi thin the quantum dot are dramatic for asymmetric structures, but negli gible in symmetric structures.