Extraction of many-body configurations from nonlinear absorption in semiconductor quantum wells

TL;DR

This paper develops a method to extract detailed many-body electronic configurations from time-resolved nonlinear absorption spectra in GaAs quantum wells, revealing complex interactions and transient phenomena.

Contribution

It introduces a microscopic theory linking spectral changes to specific many-body configurations and transient gain effects in semiconductor quantum wells.

Findings

Spectral changes are attributed to electron-hole plasma, excitons, and polarization effects.

Transient gain occurs only under co-circular pump-probe conditions.

Unique mixture of many-body effects is identified from the spectra.

Abstract

Detailed electronic many-body configurations are extracted from quantitatively measured timeresolved nonlinear absorption spectra of resonantly excited GaAs quantum wells. The microscopic theory assigns the observed spectral changes to a unique mixture of electron-hole plasma, exciton, and polarization effects. Strong transient gain is observed only under co-circular pump-probe conditions and is attributed to the transfer of pump-induced coherences to the probe.