AC transport through a quantum dot:: from Kondo to Coulomb-blockade behaviour

We analyze the conductance (g) of a quantum dot (QD) in an AC potential at finite temperature. The Friedel-Langreth sum rule (FLSR) is generalized to include the effect of an AC potential and finite T. We have solved the Anderson Hamiltonian by means of a self-consistent procedure which fulfills the generalized FLSR. New features are found in the density of states (DOS) and in g when an AC voltage is applied. Our model describes the effect of an AC potential on the transition from Kondo regime to a Coulomb-blockade: behaviour as T increases. (C) 2000 Published by Elsevier Science B.V. All rights reserved.