We have investigated magnetically-induced charge redistribution within a δ modulation-doped GaAs–Al x Ga 1− x As heterojunction structure by studying the photoluminescence due to electrons from the two-dimensional (2D) electron system recombining with photoexcited holes. At well defined values of magnetic field, charge transfer occurs between this 2D electron system and the V-shaped potential well formed in the Al x Ga 1− x As by Si δ modulation-doping. This redistribution of charge is observed as discontinuities in the photoluminescence energies. From these measurements we have derived the characteristic transfer time for electrons to move between these two wells.