ELECTRIC-FIELD DEPENDENCE OF THE EIGENSTATES OF COUPLED QUANTUM WELLS

We calculate the effects of the coupling between the eigenstates of two symmetric GaAs/ Alx Ga1-x As quantum wells separated by a thin barrier with an applied electric field using a very accurate numerical method that we have developed. Energy shifts with field and overlap integrals for the symmetric and antisymmetric electron and hole eigenstates are calculated. These results are compared to a single quantum well of equivalent dimensions. As suggested in the literature, the quantum-confined Stark effect is shown to be significantly increased by the use of coupled quantum wells. Comparison with the experimental results of Chen et al. [Y. J. Chen, E. S. Koteles, B. S. Elman, and C. A. Armiento, Phys. Rev. B 36, 4562 (1987)] is made with surprisingly good agreement.