Intersubband electronic Raman scattering in narrow GaAs single quantum wells dominated by single-particle excitations

TL;DR

This study investigates intersubband electronic Raman scattering in narrow GaAs/AlAs quantum wells, revealing that single-particle excitations dominate in wells narrower than 10 nm with high electron concentrations, with characteristic spectral features.

Contribution

It provides experimental evidence that single-particle excitations dominate Raman scattering in narrow quantum wells, highlighting the dependence on well width and electron concentration.

Findings

Single-particle excitations dominate in narrow QWs under 10 nm.

Raman shift and line shape vary with incident photon energy.

Well-width dependence confirms the nature of excitations.

Abstract

We measured resonant Raman scattering by intersubband electronic excitations in GaAs/AlAs single quantum wells (QWs) with well widths ranging from 8.5 to 18 nm. In narrow (less than 10 nm) QWs with sufficiently high electron concentrations, only single-particle excitations (SPEs) were observed in intersubband Raman scattering, which was confirmed by the well-width dependence of Raman spectra. We found characteristic variations in Raman shift and line shape for SPEs with incident photon energy in the narrow QWs.