Palestrante: Paulo Ventura Santos* (Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany)

Resumo: Excitons mediate the interaction between photons and electronic excitations in a semiconductor: this property makes them good candidates for the storage and processing of photonic information in the solid-state. In this talk, I will introduce a concept for the storage and processing of opto-electronic information based on the transport and manipulation of spatially indirect excitons in GaAs quantum well structures by surface acoustic waves (SAWs) [1]. A SAW can trap excitons and transported over millimeter-distances along its propagation direction. The exciton transport direction can be controlled by electrostatic gates and interfering acoustic beams: this feature is used to demonstrate an exciton-based optical multiplexer.[2,3] We show that spin-polarized excitons can be transported over several tens of micrometer along the quantum well plane. Furthermore, the spin polarization of the moving excitons can be controlled by electrostatic fields [2,3,4]. The controlled acoustic transport of excitons thus provide an efficient pathway for spin manipulation in semiconducting nanostructures.