Influence of Coulomb repulsion on the Aharonov-Bohm effect in a quantum dot

We consider the Aharonov-Bohm (AB) effect in the quantum Hall regime due to resonant tunneling into circulating edge states in a disk-shaped two-dimensional electron gas. We point out that the AB effect requires the incremental charging of the disk by single electrons. The charging energy is shown to reduce the frequency of the magnetoconductance oscillations. We predict the phenomenon of the ``Coulomb blockade of the Aharonov-Bohm effect'': The AB effect is suppressed in a disk of small capacitance, but can be recovered by making a large hole in the center of the disk.