Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 44: Semiconductor Microcavities and Entangled States in Quantum Dots
HL 44.3: Hauptvortrag
Donnerstag, 29. März 2007, 15:00–15:30, H15
Quantum optical studies on laterally coupled quantum dots and pillar microcavities — •P. Michler1, Gareth Beirne1, C. Hermannstädter1, S. M. Ulrich1, Serkan Ates1, L. Wang2, A. Rastelli2, O. G. Schmidt2, C. Gies3, J. Wiersing3, F. Jahnke3, S. Reitzenstein4, C. Hoffmann4, A. Löffler4, and A. Forchel4 — 1Universität Stuttgart, Institut für Strahlenphysik, Allmandring 3, 70569 Stuttgart — 2Max-Planck Institut für Festkörperforschung, Heisenbergstr.1, 70569 Stuttgart — 3Institut für Theoretische Physik, Universität Bremen, Otto-Hahn-Allee, 28359 Bremen — 4Technische Physik, Universität Würzburg, Am Hubland, 97074 Würzburg
During the last few years remarkable progress has been achieved in the development of coupled semiconductor quantum dots and high-quality microcavities which might open the way for new applications in the field of quantum information processing. We have fabricated pairs of laterally coupled (In,Ga)As QDs and demonstrate interdot electron coupling using optical techniques. The degree of tunnel coupling can be controlled by applying a static electric field along the quantum dot molecule (QDM) axis. By applying a voltage the electron probability can be reversibly shifted to either QD, and the QDM can be used to create a wavelength-tunable single photon emitter. Furthermore we present measurements of first- and second-order coherence of quantum-dot micropillar lasers. Our results show a broad threshold region for the observed high-β microcavities. The intensity jump is accompanied by both pronounced photon intensity fluctuations and strong coherence length changes. The results are in good agreement with a novel semiconductor laser theory.