Dynamics of two-pair correlations induced by simultaneous excitation of excitonic and band-to-band continuum transitions

Autor: J. Wühr, Tilmann Kuhn, Vollrath M. Axt
Rok vydání: 2003
Předmět:
Zdroj: physica status solidi (b). 238:556-560
ISSN: 1521-3951
0370-1972
DOI: 10.1002/pssb.200303189
Popis: The impact of all kinds of two-pair correlations (biexcitons, exciton-exciton scattering states, two free electron-hole pairs) on four-wave-mixing (FWM) signals generated by ultra-short optical pulses that simultaneously excite excitons and free electron-hole pairs is analyzed. Signatures of two-pair correlations are identified by comparing the full theory with mean-field (MF) results. For systems with strong exciton binding two-pair correlations suppress changes of the line width of the excitonic emission that are predicted by the MF theory when the central excitation energy is varied above the band edge. For systems with weakly bound excitons the presence of two-pair correlations leads to an emission in between the exciton and the band edge with a complex line shape which strongly depends on the excitation energy.
Databáze: OpenAIRE