Effect of vertical transport on superlattice luminescence in the presence of an in-plane magnetic field

The effect of the vertical transport of carriers on the luminescence from a ${\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}/\mathrm{G}\mathrm{a}}_{1-x}{\mathrm{Al}}_x\mathrm{As}$ superlattice (SL) in the presence of a magnetic field is studied both experimentally and theoretically. Measurements are reported for magnetic fields directed both perpendicular and parallel to the SL axis and taking values up to 42 T. In the case of an in-plane magnetic field, two threshold fields $B_1$ and $B_2$ are defined. The lower field $B_1,$ which is measured experimentally, corresponds to the field at which resonance between the minibands of neighboring SL quantum wells (QW’s) is destroyed. The higher field $B_2$ corresponds to the field at which the carriers remain completely localized within the QW. A theoretical model is used to analyze these results by approximating the SL potential to δ-function-type barriers. The measured and calculated values of $B_1$ are found to be in a good agreement with each other.