||A. M. Fox, D. A. B. Miller, G. Livescu, J.
E. Cunningham, J. E. Henry, and W. Y. Jan "Excitons in Resonantly Coupled Quantum
Wells" SPIE 1283 Quantum-Well and Superlattice Physics III, 164-174, (1990).
authors have studied excitonic effects in resonantly coupled GaAs/AlGaAs multiple quantum
wells. They use photocurrent spectroscopy to deduce the resonant field from the
field-dependent exciton energies, and find an unexpected variation of approximately 10% in
the resonant field between different excitonic transitions involving the same coupled
electron levels. They construct a variational model of the coupled excitons which explains
the results in terms of Coulomb mixing of the delocalised electron states