Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 18: Focussed Session: Strong Light Matter Coupling I
HL 18.4: Vortrag
Dienstag, 23. März 2010, 10:45–11:00, H13
Multi-Quantum-Well Microcavity Structures for electrical excitation of Exciton-Polaritons — •Matthias Lermer1, Arash Rahimi-Iman1, Christian Schneider1, Sven Höfling1, Stephan Reitzenstein1, Lukas Worschech1, Alfred Forchel1, Na Young Kim2, and Yoshihisa Yamamoto2 — 1Technische Physik, Universität Würzburg, D-97074 Würzburg, Germany — 2E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA
In semiconductor microcavities strong coupling between quantum-well (QW) excitons and cavity-photons can be realized. In low excitation regime, bosonic quasiparticles, the so called exciton-polaritons, are formed, consisting of half-light/half-matter and exhibit unique properties like stimulated scattering, Bose-Einstein-Condensation and lasing, which have been intensively investigated so far by optical excitation.
We have studied planar AlGaAs/AlAs microcavities featuring 1, 4 and 12 GaAs/AlAs QWs and investigated the strong coupling in photoluminescence and reflection for varying temperatures. To amplify the process of stimulated scattering, it is important to enhance the density of polaritons, thus in the presented work we carefully increased the number of QWs in the device. At the same time homogenous pumping of the QWs has to be ensured as it is critical for the purpose of realization of an electrically driven polariton structure. In that way we could achieve a light emitting diode operation in the strong coupling regime, namely a polariton diode. Our results show that the number of GaAs/AlAs QWs in combination with a sophisticated cavity design is of key importance for studies in the field of polaritronics.