Activated transport through a quantum dot with extended edge channels

We study the Coulomb-blockade oscillations in the conductance of a quantum dot in the quantum Hall effect reigme. Our model calculation generalizes the self-consistent Thomas-Fermi approach of McEuen et al. for isolated dots, to include extended as well as localized edge states. We find that a Coulomb blockade can exist for the transfer of an electron from an extended to a localized edge state, in accordance with recent experiments by Alphenaar et al. We demonstrate the crucial role played by the incompressibility of the extended edge states, and predict that the conductance oscillations will be suppressed at lower temperatures when an odd rather than an even number of extended edge channels is present.