Role of Coulomb correlations for femtosecond pump-probe signals obtained from a single quantum dot

Huneke J, D'Amico I, Machnikowski P, Thomay T, Bratschitsch R, Leitenstorfer A, Kuhn T

Research article (journal)

Abstract

We present a theoretical analysis of femtosecond pump-probe experiments performed on a single negatively charged quantum dot. The influence of Coulomb-correlation effects as well as carrier relaxation on transient transmission change signals is investigated. Our model describes ultrafast disappearance of the fundamental trion absorption due to instantaneous Coulomb renormalizations and a delayed onset of gain at the same frequency, as found in the measurements. Going beyond previous experimental information, we predict that after spin-conserving carrier relaxation, new optical transitions exhibiting either gain or absorption should emerge that build up on a picosecond timescale. The time dependence of these new transitions provides insight into details of the carrier relaxation processes.

Details zur Publikation

Release year: 2011
Link to the full text: http://www.scopus.com/inward/record.url?partnerID=yv4JPVwI&eid=2-s2.0-80053580717&md5=877d4affb2ed46ef393585fc7ff57f22