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Accueil du site > Semiconducteurs, Matériaux et Capteurs > Equipe : Physique de l’Exciton, du Photon et du Spin > Thème : Couplage fort exciton-photon

Thème : Couplage fort exciton-photon


Le contrôle du couplage entre excitons et photons est un domaine de recherche en pleine expansion à la frontière entre de nombreuses disciplines de la physique de la matière condensée : les nanotechnologies, la théorie de l’électromagnétisme et de l’optique quantique, la spectroscopie des nanostructures confinant excitons et photons. Nos activités actuelles concernent le régime de couplage fort entre excitons et photons ou excitons et plasmons, et se focalisent sur la compréhension fine de la physique des quasi-particules mixtes exciton-photon, appelées polaritons. Les principaux axes de recherche sont reliés à la quête du laser à polariton haute température dans ZnO, à la détermination des interactions polariton-polariton dépendantes du spin dans les microcavités III-V, et au couplage entre plasmons de surface dans les nano-particules métalliques et les excitons dans des puits quantiques GaAs ou des semiconducteurs organiques.



ZnO Microcavities

Excitons in wide band gap semiconductors, and especially ZnO, present binding energies and oscillator strength one order of magnitude larger than GaAs. Our theoretical predictions in 2002 have shown that the strong coupling in ZnO microcavities can be robust up to room temperature, with specificities recently investigated in our group. Within the ANR project ZOOM, coordinated by our group (in collaboration with CRHEA, LASMEA and LPN), this strong coupling has been demonstrated at 300K. Our (...)

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Strong exciton-plasmon coupling

Plasmons are an interesting alternative to cavities in order to confine the electromagnetic field. Their coupling to semiconductor excitons (GaAs quantum wells) is the purpose of the ANR project SCOP. Metallic nano-particles possess a localized surface plasmon mode which energy depends on their size and geometry. Those modes can interact with GaAs or organic semiconductor excitons. The modelling and the optimization of dedicated structures allowed us to specify geometrical constraints for (...)

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Polariton spin dynamics

We were also interested in polaritons spin dynamics in II-VI microcavities with embedded diluted magnetic quantum wells, and III-V microcavities with embedded GaInAs quantum wells, in the framework of the european RTN network CLERMONT2 (2002-2007). This work has been done in collaboration with LPN and SP2M/CEA for microcavities growth, and with LASMEA and A. Kavokin for modelling. It gave rise to the PhD thesis of Adalberto Brunetti in May 2007, and to an invited paper at the PLMCN7 (...)

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The originality of our research project concerning this issue relies on our position at interfaces : between microcavities and the subtle spin spectroscopy for GaAs microcavities, between microcavities and wide bandgap semiconductors for ZnO-based cavities, and between plasmonics and exciton physics for the strong exciton-plasmon coupling. These works require complex samples with respect to their conception, their optimization as well as the multiplicity of fabrication techniques involved (...)

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