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Coherent signature of differential transmission signals in semiconductors: Theory and experiment

Kohärentes Vorzeichen von differentiellen Transmissionssignalen in Halbleitern: Theorie und Praxis


Physical Review. B 55 (1997), Nr.24, S.16404-16413
ISSN: 0163-1829
ISSN: 1098-0121
ISSN: 0556-2805
Fraunhofer IAF ()
heterostructure; Heterostruktur; III-V Halbleiter; III-V semiconductors; optical measurement; optische Messung

Transient pump-probe signals of a GaAs/Al(x)Ga(1-x)As quantum well are investigated both theoretically and experimentally for different excitation conditions. The calculations are based on a microscopic density-matrix approach taking higher-order correlations into account. We present spectrally resolved transients which provide insights into the nature of the differential transmission change. Especially the complex phase signature of heavy-hole-light-hole quantum beats in dependence of the detection energy allows for an identification of different microscopic processes in the pump-probe signal. The theoretical results are verified experimentally by comparison with the coherent and incoherent parts of the time-resolved data. We find a dominant role of the Coulomb-induced correlations up to the chi(exp3)relevant four-point level in the coherent signature in comparison to the Pauli blocking contributions.