Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 104: Quantum Dots and Wires: Optical Properties V (mainly Indiviual Photons)
HL 104.2: Talk
Friday, March 30, 2012, 12:00–12:15, EW 201
Photons on demand from an electrically driven single quantum dot under pulsed excitation — •Matthias Florian1, Paul Gartner1, Christopher Gies1, Christian Kessler2, Fabian Hargart2, Matthias Reischle2, Wolfgang-Michael Schulz2, Marcus Eichfelder2, Robert Roßbach2, Michael Jetter2, Peter Michler2, and Frank Jahnke1 — 1Institut für Theoretische Physik, Universität Bremen — 2Institut für Halbleiteroptik und Funktionelle Grenzflächen, Universität Stuttgart
Electrically driven, integrated single-photon sources are key components for applications in quantum information. Cavity-enhanced quantum dots (QDs) offer fast relaxation and recombination times, enabling high repetition rates. Short electrical excitation pulses, on the other hand, are a challenge. In a collaboration between theory and experiment, we study the influence of electrical excitation-pulse parameters on the single photon emission from a single QD. On the basis of the time-integrated photon autocorrelation function, the anti-bunching is determined. The theoretical description is based on a solution of the von-Neumann equation, where we consider the single-particle states of the QD, together with many-body effects introduced by the Coulomb and light-matter interaction. The electrical pump pulse creates carriers in the delocalized barrier or WL states, from which we model the capture into the localized QD states, as well as intraband scattering and dephasing, via Lindblad terms. The reduction of the anti-bunching with increasing pulse width is in quantitative agreement with our experiments and defines the operational regime for practical applications.