Direct and indirect excitons in asymmetric double quantum wells

We studied, theoretically, the optical absorption spectra for asymmetric double quantum wells, in the presence of electric and magnetic fields. Recent experimental results show clearly the different behavior in the luminescence peaks for the indirect exciton IX and left direct exciton DX as a function of the external electric field. We show that the presence of a peak near the DX peak, attributed to an impurity bound left DX in the experimental results, could be a consequence of the non-trivial mixing between excitonic states.