The coupling between quasilocalized states in semiconductor double quantum barriers

The interaction between above-barrier states quasilocalized in barrier layers was studied in a double quantum barrier configuration. Optical transmission experiments were performed on type-II CdSe/ZnTe samples, in which the valence band has a double-barrier structure. Numerical studies reveal a change of symmetry for the coupled quasilocalized states, as a function of the separation between the two barriers. Consequently, the strongest optical transition occurs between different pairs of states as the barrier separation changes. The behavior is illustrated by both experimental and numerical results.