Carrier-induced changes in the phase resolved reflection of GaAs quantum wells
Universität Rostock, Fachbereich Physik, 18051 Rostock,
Corresponding author: a email@example.com
Revised: 23 September 2002
Published online: 19 December 2002
The influence of thermalized non-coherent carriers on the dielectric function of GaAs/AlAs quantum wells is investigated by reflection spectroscopy. Experiments are performed using the method of spectral interferometry, where both amplitude and phase of reflected pulses can be determined. For low excitation density the complex coefficient of reflection can be described using as dielectric function a broadened Elliot formula. With increasing carrier density pronounced nonlinearities appear in both amplitude and phase due to many-body effects between excited carriers. The nonlinear behavior fits very well to the results of a many-body theory based on the Semiconductor Bloch equations including memory effects in the scattering processes between carriers and the polarization induced by the probe pulse.
PACS: 71.35.-y – Excitons and related phenomena / 71.45.Gm – Exchange, correlation, dielectric and magnetic response functions, plasmons / 78.20.-e – Optical properties of bulk materials and thin films / 78.67.De – Quantum wells
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002