Meier, L. and Fuhrer, A. and Ihn, Thomas and Ensslin, Klaus and Wegscheider, Werner and Bichler, Max
Single-electron effects in a coupled dot-ring system.
Physical Review B 69 (24), p. 241302.
Aharonov-Bohm oscillations are studied in the magnetoconductance of a micron-sized open quantum ring coupled capacitively to a Coulomb-blockaded quantum dot. As the plunger gate of the dot is modulated and tuned through a conductance resonance, the amplitude of the Aharonov-Bohm oscillations in the transconductance of the ring displays a minimum. We demonstrate that the effect is due to a single-electron screening effect, rather than to dephasing. Aharonov-Bohm oscillations in a quantum ring can thus be used for the detection of single charges.