Lateral confinement and inter-wire coupling of exciton in 4-16 nm wide GaAs/AlGaAs quantum wires observed by magnetoluminescence

Abstract

The result on magnetoluminescence study of the exciton in GaAs/AlosGao.sAs quantum wire (QWR) superlattice grown on vicinal GaAs substrate are reported. For 30 T, the diamagnetic shift is 7.8 meV for QWR of 4 nm wide, while it is 11 meV for QWR of 8 nm or wider. For 4 nm QWR, the diamagnetic shift remains the same up to 17 T for the magnetic field parallel and angled to the growth direction. But, it saturates in the angles geometry at 17 T where the cyclotron diameter becomes comparable to QWR width. If the lateral confinement model is introduced in the formation of exciton in QWR, the saturation can be interpreted as the breaking of inter-wire coupling.