AHARONOV-BOHM EFFECT IN THE QUANTUM HALL REGIME

Abstract

We have fabricated quantum rings in a GaAs/GaAlAs heterostructure 2DEG by local anodic oxidation with an atomic force microscope. In low magnetic fields we observe Aharonov-Bohm oscillations with a period of 60 mT corresponding to an effective ring diameter of 300 nm. In the high field regime, between filling factors ν = 2/3 and ν = 3, we observe Aharonov-Bohm oscillations of quantum Hall edge channels with a surprisingly large period, Δ B = 163 mT , corresponding to an edge channel around the inner diameter of the ring.