Accueil >
Production scientifique
|
|
Transport of Indirect Excitons in Polar GaN/AlGaN Quantum Wells. 
Auteur(s): Fedichkin F., Jouault B., Andreakou P., Valvin P., Vladimirova M., Guillet T., Bretagnon T., Dussaigne Amélie, Grandjean Nicolas, Lefebvre P.
Conference: 15th conference on Physics of Light-Matter Coupling in Nanostructures (PLMCN15) (Montpellier, FR, 2014-06-09)
|
|
|
|
Transport of Indirect Excitons in Polar GaN/AlGaN Quantum Wells.
Auteur(s): Fedichkin F., Andreakou P., Valvin P., Vladimirova M., Guillet T., Bretagnon T., Dussaigne Amelie, Grandjean Nicolas, Lefebvre P.
(Affiches/Poster)
Condensed Matter in Paris – CMD25 – JMC14. (Paris, FR), 2014-08-24
|
|
|
|
Transport of Indirect Excitons in Polar GaN/AlGaN Quantum Wells.
Auteur(s): Fedichkin F., Andreakou P., Valvin P., Vladimirova M., Guillet T., Bretagnon T., Dussaigne A, Grandjean N, Lefebvre P.
(Affiches/Poster)
Compound Semiconductor Week 2014 (Montpellier, FR), 2014-05-11Texte intégral en Openaccess : 
Ref HAL: hal-01305161_v1
Exporter : BibTex | endNote
Résumé: We present spatially- and time-resolved photoluminescence experiments on polar GaN/AlGaN quantum well structures,showing exciton propagation distance of tens of micrometers from generation position and exciton radiative lifetimes oftens of microseconds. We study in detail the dynamics and range of their relaxation/diffusion along the growth plane, asa function of temperature.
|
|
|
|
Nonlinear Optical Probe of Indirect Excitons
Auteur(s): Nalitov A. V., Vladimirova M., Kavokin A., Butov L. V., Gippius N. A.
(Article) Publié:
-Physical Review B Condensed Matter And Materials Physics (1998-2015), vol. 89 p.155309 (2014)
Texte intégral en Openaccess : 
Ref HAL: hal-02046568_v1
Ref Arxiv: 1311.0165
DOI: 10.1103/PhysRevB.89.155309
WoS: 000334120100002
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
11 Citations
Résumé: We propose the application of nonlinear optics for studies of spatially indirect excitons in coupled quantum wells. We demonstrate, that despite their vanishing oscillator strength, indirect excitons can strongly contribute to the photoinduced reflectivity and Kerr rotation. This phenomenon is governed by the interaction between direct and indirect excitons. Both dark and bright states of indirect excitons can be probed by these nonlinear optical techniques.
|
|
|
|
Dipolar exciton fluids in (Al,Ga)N/GaN quantum wells
Auteur(s): Kruse A., Valvin P., Vladimirova M., Guillet T., Bretagnon T., Andreakou P., Grandjean Nicolas, Lefebvre P.
(Affiches/Poster)
14th International Conference on the Physics of Light-Matter Coupling in Nanostructures - PLMCN14 (Hersonissos, Crète, GR), 2013-05-27
|
|
|
|
Ballistic spin transport in exciton gases
Auteur(s): Kavokin A., Vladimirova M., Jouault B., Liew Timothy, Leonard Jason, Butov Leonid
(Article) Publié:
-Physical Review B Condensed Matter And Materials Physics (1998-2015), vol. 88 p.195309 (2013)
Texte intégral en Openaccess :
Ref HAL: hal-00911638_v1
DOI: 10.1103/PhysRevB.88.195309
WoS: 000327239200002
Exporter : BibTex | endNote
19 Citations
Résumé: Traditional spintronics relies on spin transport by charge carriers, such as electrons in semiconductor crystals. The challenges for the realization of long-range electron spin transport include rapid spin relaxation due to electron scattering. Scattering and, in turn, spin relaxation can be effectively suppressed in excitonic devices where the spin currents are carried by electrically neutral bosonic quasiparticles: excitons or exciton-polaritons. They can form coherent quantum liquids that carry spins over macroscopic distances. The price to pay is a finite lifetime of the bosonic spin carriers. We present the theory of exciton ballistic spin transport which may be applied to a range of systems supporting bosonic spin transport, in particular to indirect excitons in coupled quantum wells. We describe the effect of spin-orbit interaction for the electron and the hole on the exciton spin, account for the Zeeman effect induced by external magnetic fields and long-range and short-range exchange splittings of the exciton resonances. We also consider exciton transport in the nonlinear regime and discuss the definitions of the exciton spin current, polarization current, and spin conductivity.
Commentaires: 16 pages, 9 figures
|
|
|
|
Anomalously large spin susceptibility enhancement in n-doped CdMnTe quantum wells
Auteur(s): Ben Cheikh Z., Cronenberger S., Vladimirova M., Scalbert D. , Boujdaria Kais, Baboux Florent, Perez Florent, Wojtowicz Thomas, Karzewski Gregorz
Conference: ICPS (Zurich, FR, 2012-07-29)
Actes de conférence: Proceedings of the 31st International Conference on the Physics of Semiconductors, vol. 1566 p.349 (2013)
Ref HAL: hal-00925573_v1
DOI: 10.1063/1.4848429
WoS: 000331793000174
Exporter : BibTex | endNote
Résumé: We report on time-resolved Kerr rotation (TRKR) experiments done on n-doped CdMnTe quantum wells (QWs), in the regime where strong coupling between the electron and the Mn spin-flip excitations shows up. It has been proposed previously to deduce the 2D electron gas spin susceptibility from the coupling energy between these spin excitations. Here we measure the coupling energy on a high mobility sample down to very low excitation density, and compare the results with spin-flip Raman scattering (SFRS) on the same sample. The electron spin polarizations measured by TRKR and SFRS are found in relatively good agreement. However the spin susceptibility measured by TRKR exceeds systematically the values predicted by many-body theory. This could be an indication that the two-oscillator model used to describe mixed electron-Mn spin excitations needs to be improved.
|
