Estimating the memory time induced by exciton-exciton scattering.

Phys Rev Lett

Institut für Festkörpertheorie, Westfälische-Wilhelms Universität, Wilhelm-Klemm-Strasse 10, 48149 Münster, Germany.

Published: September 2004

It is shown that lower bounds for the effective memory time induced by two-pair correlations can be estimated by monitoring changes of the shape of excitonic four-wave-mixing spectra. Experimentally we demonstrate a memory time of at least 540 fs for a ZnSe single quantum well. Microscopic calculations reveal that this lower bound is not sharp. Interactions retarded by more than 800 fs are shown to influence the dynamics, reflecting the presence of a long time tail in the memory kernel.

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http://dx.doi.org/10.1103/PhysRevLett.93.127402DOI Listing

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