Thumbnail
Access Restriction
Open

Author Kner, P. ♦ Bar-Ad, S. ♦ Marquezini, M. V. ♦ Chemla, D. S. ♦ Loevenich, R. ♦ Schaefer, W.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ CARRIER DENSITY ♦ GALLIUM ARSENIDES ♦ FREQUENCY MIXING ♦ EXCITONS ♦ CORRELATIONS ♦ MAGNETO-OPTICAL EFFECTS ♦ TIME RESOLUTION
Abstract Mean-field, Hartree-Fock theory has been successful in explaining many nonlinear optical experiments in semiconductors. But recently experiments have shown important cases where the mean-field theory (the semiconductor Bloch equations) fails. One such case is bulk GaAs in a strong magnetic field. Here the exciton-exciton interaction can be tuned by varying the magnetic field, providing an excellent method for studying the transition from a regime where mean-field theory is valid to a regime where exciton-exciton correlations must be taken into account. We perform ultrafast time-resolved four-wave mixing on bulk GaAs in a magnetic field, and compare our experimental results with theoretical calculations which go beyond Hartree-Fock theory. We find excellent qualitative agreement. Furthermore, because of the strong correlations that are present, GaAs in a magnetic field presents an excellent opportunity to study the exciton-exciton correlations themselves. We investigate the coherence of the exciton-exciton correlations as the temperature and free-carrier density are varied, and find a surprising sensitivity of the exciton-exciton correlation coherence to these parameters. {copyright} {ital 1999} {ital The American Physical Society}
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 1999-08-01
Publisher Place United States
Journal Physical Review, B: Condensed Matter
Volume Number 60
Issue Number 7


Open content in new tab

   Open content in new tab