In-Plane Magnetolumnescence of Modulation-Doped GaAs/AlGaAs Coupled Double Quantum Wells

In-plane magnetic field photoluminescence spectra from a series of GaAs/AlGaAs coupled double quantum wells show distinctive doublet structures related to the symmetric and antisymmetric states. The magnetic field behavior of the upper transition from the antisymmetric state strongly depends on sample mobility. In lower mobility samples, the transition energy shows an $\cal N$-type kink with fields (namely a maximum followed by a minimum), whereas higher mobility samples have a linear dependence. The former is due to a homogeneous broadening of electron and hole states and the results are in good agreement with theoretical calculations.