Boundary effects on the resonant coupling of the excitation modes of semiconductor quantum wells

Abstract

An alternative approach based on the invariant imbedding method and the random phase approximation is used to study the excitation spectra of both neutral and parabolic quantum wells. Compared to other methods, this approach is efficient and leads to more stable solutions. It also provides a convenient way for studying boundary effects. The calculated excitation spectra for both types of quantum well agree well with experimental observations and previous calculations. The effects of the boundary condition on the excitation spectra were extensively studied. It was found that the positions and relative strengths of resonant peaks are sensitive to the boundary condition. The evolution of some of the resonant peaks can be attributed to the coupling between collective plasma modes and the intersubband transitions.