Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 37: Ultrafast Phenomena II
HL 37.2: Vortrag
Dienstag, 8. März 2016, 15:00–15:15, H10
Dynamics of exciton-polariton condensates in semiconductor microcavities with periodic potentials — •Xuekai Ma1, Stefan Schumacher1, and Oleg Egorov2 — 1Physics Department, Universität Paderborn, Warburger Strasse 100, 33098 Paderborn, Germany — 2Institute of Condensed Matter Theory and Solid State Optics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
Exciton-polaritons are quasi-particles made of quantum well (QW) excitons coupled to cavity photons. They have very small effective mass (10-4me) and lifetimes on the tens of picoseconds scale. Due to their photonic properties, they can be excited by light and probed, respectively. Due to their excitonic properties, nonlinearity is introduced into this system at elevated densities. Polaritons, which are composite bosons, can undergo a condensation process (with similarities to Bose-Einstein condensation) under incoherent excitation. Many features in the dynamics of polariton condensates can be described by a modified Gross-Piteavskii equation (GPE). Here, we study the nonlinear dynamics of polariton condensates in periodic potentials. In the presence of a periodic potential, a band structure including a band-gap can be obtained. We show that polariton condensates can occupy and switch between different energy states by changing the pump excitation intensity and shape. Our simulation results agree very well with recent experimental results.