Anomalous quantum Hall effect induced by nearby quantum dots

Abstract

Transport measurements in high magnetic fields have been performed on two-dimensional electron system (2DES) separated by a thin barrier layer from a layer of InAs self-assembled quantum dots (QDs). Clear feature of quantum Hall effect was observed in spite of presence of QDs nearby 2DES. However, both magnetoresistance, ρ xx , and Hall resistance, ρ xy , are suppressed significantly only in the magnetic field range of filling factor in 2DES ν < 1 and voltage applied on a front gate V g > 0 V . The results indicate that the electron state in QDs induces spin-flip process in 2DES.