We exploit the influence of the Coulomb interaction between electrons and holes on the electron spin relaxation in a (110)-GaAs quantum well to unveil excitonic signatures within the many particle electron-hole system. The temperature dependent time- and polarization-resolved photoluminescence measurements span five decades of carrier density, comprise the transition from localized excitons over quasi free excitons to an electron-hole plasma, and reveal strong excitonic signatures even at relatively high densities and temperatures.
@article{arxiv.1103.2474,
title = {Electron spin relaxation as evidence of excitons in an electron-hole plasma},
author = {S. Oertel and S. Kunz and D. Schuh and W. Wegscheider and J. Hübner and M. Oestreich},
journal= {arXiv preprint arXiv:1103.2474},
year = {2011}
}