Influence of Localization on the Optical Nonlinearities Induced by Exciton-Exciton Interaction in Semiconductor Nanostructures
Abstract
The signature of exciton-exciton interaction in the four wave mixing response at the fundamental excitonic resonance is investigated as a function of the localization strength in GaAs single and multiple quantum wells. The four wave mixing is found to be dominated by signals induced by exciton-exciton interaction. For co-polarization of the incident pulses, excitation-induced dephasing (EID) is dominating the signal generation, while for cross-linear polarized excitation, the signal is generated from bound and unbound biexciton transitions. The relative strength of the ElD compared to phase-space filling shows a maximum for localization energies comparable to the homogeneous broadening. The biexciton binding energy increases for localization energies comparable to or larger than the biexciton binding, while the biexciton continuum edge shifts to energies above the exciton resonance. Simuiltaneously, the binding energy gets inhomogeneously broadened, and the oscillator strength of the biexciton confinuum is reduced by the quantization of the excitonic states in the localization potential.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1998
- Accession Number
- ADP012808
Entities
People
- Jorn M. Hvam
- Wolfgang W. Langbein
Organizations
- Technical University of Denmark