Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 59: Quantum Dots and Wires, Optical Properties V

HL 59.7: Vortrag

Donnerstag, 25. März 2010, 17:30–17:45, H14

Coherent Coupling of Two Different Semiconductor Quantum Dots via an Optical Cavity Mode — •Arne Laucht, José M. Villas-Bôas, Norman Hauke, Felix Hofbauer, Gerhard Böhm, Michael Kaniber, and Jonathan J. Finley — Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching, Germany

We present a combined experimental and theoretical study of a strongly coupled system consisting of two spatially separated self-assembled InGaAs quantum dots and a single optical nanocavity mode. Due to their different size and strain profile, the two dots exhibit markedly different electric field dependences due to the quantum confined Stark effect. This allows us to tune them into resonance simply by changing the applied bias voltage and to independently tune them into the photonic crystal nanocavity mode. Photoluminescence measurements show a characteristic triple peak during the double anticrossing, which is a clear signature of a coherently coupled system of three quantum states. We fit the emission spectra of the coupled system to theory and are able to investigate the coupling between the two quantum dots directly via the cavity mode. Furthermore, we investigate the coupling between the two quantum dots when they are detuned from the cavity mode in a V-system where dephasing due to incoherent losses from the cavity mode can be reduced.