Aharonov–Bohm effect of quantum Hall edge channels

We fabricated quantum rings by means of local anodic oxidation with an atomic force microscope on GaAs/AlGaAs-heterostructures. In low magnetic fields we observe the Aharonov–Bohm effect of 1D channels in the ring with a period of 60–80 mT, for different devices. By careful tuning the in-plane gate voltages of the ring we also observe Aharonov–Bohm type of oscillations in the quantum Hall regime, with a surprisingly large period when compared to the low field Aharonov–Bohm oscillations.