Evidence of six-particle Coulomb correlations in six-wave-mixing signals from a semiconductor quantum well

Titelangaben

Axt, Vollrath Martin ; Bolton, S. R. ; Neukirch, U. ; Sham, L. J. ; Chemla, D. S.:
Evidence of six-particle Coulomb correlations in six-wave-mixing signals from a semiconductor quantum well.
In: Physical Review B. Bd. 63 (2001) Heft 11 . - 115303.
ISSN 0163-1829
DOI: https://doi.org/10.1103/PhysRevB.63.115303

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Abstract

Six-wave-mixing signals from a ZnSe quantum well are analyzed experimentally and with a microscopic density-matrix description using the dynamics-controlled-truncation scheme. For each physically distinct combination of polarizations of the exciting pulses, the spectrum of six-wave-mixing emission is measured as a function of time delay. The experimental results are compared with calculations performed at different levels of approximation. Although the leading order contributions to six-wave-mixing signals are of fifth order in the laser field, we show that there are significant signal components that are due to at least χ(7) processes. The sensitivity of six-wave-mixing signals to high-order Coulomb correlations is demonstrated. Six-point density matrices are found to be indispensable for the interpretation of our experiments, while some details seem to indicate the involvement of even higher-order correlation functions. Furthermore, we find a remarkable dynamical decoupling of spectral signatures and the delay-time behavior after excitation with linearly polarized pulses.