Influence of Coulomb correlations on the quantum well intersubband absorption at low temperatures

TL;DR

This paper develops a theoretical model to study how Coulomb correlations affect intersubband absorption in doped GaAs/AlGaAs quantum wells at low temperatures, revealing significant spectral broadening and renormalization.

Contribution

It introduces a new theory incorporating electronic ground state correlations into intersubband absorption analysis at low temperatures.

Findings

Ground state correlations increase spectral broadening by up to a factor of 3 at 1 K.

Coulomb interactions cause notable renormalization of the absorption spectrum.

Electron-phonon scattering reduces the impact of electronic correlations.

Abstract

We present a theory for the intersubband absorption including electronic ground state correlations in a doped GaAs/Al_{35}Ga_{65}As quantum well system. Focusing on the influence of the Coulomb interaction among the carriers at low temperatures, we find that the ground state correlations lead to an increased renormalization and spectral broadening of the absorption spectrum. At T = 1 K, its full width at half maximum is increased by up to a factor 3. The inclusion of electron-phonon scattering strongly reduces the relative impact of the electronic correlations.