Direct and indirect exciton mixing in a slightly asymmetric double quantum well

We studied, theoretically, the optical absorption spectra for a slightly asymmetric double quantum well (DQW), in the presence of electric and magnetic fields. Recent experimental results for a 10.18/3.82/9.61 nm GaAs Al .33Ga.67As DQW 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. PACS numbers: 73.20.Dx, 73.23.-b, 78.20.Ls,78.66.-w Submitted to: J. Phys.: Condens. Matter