Transport mechanism in the quantum well embedded with quantum dots

Abstract

AbstractElectron transport in single and double quantum well system embedded with InAs quantum dots is investigated by carrying out magnetoresistance measurements at 1.2 K. At low carrier densities, the electrons are strongly localized due to disorder and undergo magnetic field induced insulator to quantum Hall liquid transitions characterized by temperature independent crossing points. At higher carrier densities no such magnetic field induced transition are observed. The potential induced by the electrons in the quantum dots were found to enhance the scattering between the edge states resulting in the substantial reduction of the width of the Hall plateau in the single quantum well system. In the double quantum well system, instead of plateaus abrupt increase in the Hall resistance is observed at integer filling factors. On sweeping the gate bias at fixed magnetic field, hysteresis effect was observed in the double quantum well system due to the charge trapping in the defect levels. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)