Many body and nonparabolicity effects in the intersubband transitions of conduction and valence bands of quantum well media

This paper highlights the strong band coupling and resulting nonparabolicity and k-dependence of the dipole moments combined with Coulomb corrections, that lead to double features in some of the multiple transitions, which can be measured by comparing and contrasting the evolution of the TE and TM modes with increasing excitation. This work also discusses the combined contributions from both types of subbands to the intersubband transitions including many body effects. Nonparabolicity in all subbands are discussed by means of a strong pump pulse generating electrons in the conduction band and holes in the valence bands, and a weak probe pulse in the infrared. Consequently conduction band signatures are predicted in the TE mode. The overall spectral shape, number of peaks and the relative oscillator strengths of the multiple transitions calculated with and without Coulomb effects are radically different, further highlighting the relevance of the theory.