Transport properties of a quantum dot in quantum Hall regimes probed by a single-electron transistor

Coulomb blockade oscillations in a semiconductor quantum dot (QD) with two confined Landau levels are investigated by probing a current through a single-electron transistor (SET) fabricated directly on top of the QD. The intradot tunneling events between the compressible regions in the dot are mapped out by measuring SET currents. Our results demonstrate that a SET can be an excellent electrometer that is extremely responsive to the local individual electron tunneling events in a closed electronic system.