Ultrafast Ellipsometry of Coherent Processes and Exciton-Exciton Interactions in Semiconductors

Abstract

The femtosecond time-resolved polarization state of the four-wave-mixing signal from a multiple quantum well exhibits a continuously varying ellipticity and a real-time rotation of the polarization ellipse at negative time delays that are dramatically different from those observed at positive delays and that are consistent with the inclusion of both many-body interactions and biexcitonic effects.