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HL: Fachverband Halbleiterphysik
HL 82: Quantum dots and wires: Cavities and photons
HL 82.7: Vortrag
Donnerstag, 14. März 2013, 16:45–17:00, H2
Photocurrent spectroscopy on single quantum dots in micropillar cavities - coherent optical manipulation and cavity quantum electrodynamics effects — •Peter Gold1, Manuel Gschrey2, Matthias Lermer1, Christian Schneider1, Sven Höfling1, Alfred Forchel1, Martin Kamp1, and Stephan Reitzenstein2 — 1Technische Physik, Universität Würzburg, Am Hubland, D-97074 Würzburg — 2Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, D-10623 Berlin
We report on photocurrent (PC) studies of single quantum dots (QDs) in electrically contacted micropillar cavities. The PC response originates from the tunneling of strictly resonantly excited charge carriers in the QDs. Here, we demonstrate coherent optical manipulation of an exciton qubit by exciting a single QD inside a micropillar cavity with picosecond laser pulses. The coherent interaction with the pulsed laser field leads to Rabi oscillations in the population dynamics of the excitonic ground state, which are monitored by the corresponding PC signal. Moreover, we study cavity quantum electrodynamics (cQED) effects in coupled QD-microcavity systems under electrical readout. We find a strong anticorrelation between radiative recombination and nonradiative tunnel escape of photoexcited carries which can be controlled by cQED effects in the Purcell regime. In fact, cavity enhanced radiative emission from a QD results in a weaker photocurrent signal which reflects the cQED controlled competition between radiative and nonradiative recombination at the single emitter level [1].
[1] Gold et al., Phys. Rev. B 86, 161301(R) (2012)