Electrical and optical correlation in the study of the depopulation effect in asymmetric quantum wells

A direct comparative analysis is done in order to establish a clear correlation between magnetoresistance and photoluminescence measurements on the depopulation effect of higher energy electronic subbands induced by a planar magnetic field in ${\mathrm{Al}}_{0.3}{\mathrm{Ga}}_{0.7}{\mathrm{A}\mathrm{s}/\mathrm{I}\mathrm{n}}_{0.15}{\mathrm{Ga}}_{0.85}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}$ asymmetric quantum wells. The observed negative magnetoresistance and decreasing photoluminescence intensity with the magnetic field is in agreement with the reduction of the second subband electron density, which is obtained by a self-consistent calculation.