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Detection of nuclear magnetization by Faraday rotation 
Auteur(s): Vladimirova M., Giri R., Cronenberger S., Scalbert D., Bloch Jacqueline, Lemaître Aristide, Kavokin K., Glazov Mikxail
Conference: PLMCN 14 (Hersonissos, GR, 2013-05-27)
Ref HAL: hal-00835618_v1
Exporter : BibTex | endNote
Résumé: We report on the nondestructive measurement of nuclear magnetization in n-GaAs via cavity enhanced Faraday rotation. In contrast with the existing optical methods, this detection scheme does not require the presence of detrimental out-of-equilibrium electrons. Specific mechanisms of the Faraday rotation are identified for (i) nuclear spins situated within the localized electron orbits, they are characterized by fast dynamics, (ii) all other nuclear spins in the sample characterized by much slower dynamics. Our results suggest, that even in degenerate semiconductors nuclear spin relaxation is limited by the presence of localized electron states and spin diffusion, rather than by Korringa mechanism.
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Spin Currents in a Coherent Exciton Gas
Auteur(s): Vladimirova M., High A. A., Hammack A. T., Leonard J. R., Yang Sen, Butov L. V., Ostatnický T., Kavokin A., Gossard A. C., Liew T. C. H., Campman K. L.
Conférence invité: PLMCN 14 (Hersonissos, GR, 2013-05-27)
Ref HAL: hal-00835599_v1
Exporter : BibTex | endNote
Résumé: We report the observation of spin currents in a coherent gas of indirect excitons. The realized long-range spin currents originate from the formation of a coherent gas of bosonic pairs--a new mechanism to suppress the spin relaxation. The spin currents result in the appearance of a variety of polarization patterns, including helical patterns, four-leaf patterns, spiral patterns, bell patterns, and periodic patterns. We demonstrate control of the spin currents by a magnetic field. We also present a theory of coherent exciton spin transport that describes the observed exciton polarization patterns and indicates the trajectories of the spin currents.
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Spin currents in a coherent exciton gas
Auteur(s): High A. A., Hammack A. T., Leonard J. R., Yang Sen, Butov L. V., Ostatnicky T., Vladimirova M., Kavokin A., Liew T. C. H., Campman K. L., Gossard A. C.
(Article) Publié:
Physical Review Letters, vol. 110 p.246403 (2013)
Texte intégral en Openaccess : 
Ref HAL: hal-00835577_v1
Ref Arxiv: 1302.3852
DOI: 10.1103/PhysRevLett.110.246403
WoS: 000320282600014
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
75 Citations
Résumé: Spin currents and spin textures are observed in a coherent gas of indirect excitons. Applied magnetic fields bend the spin current trajectories and transform patterns of linear polarization from helical to spiral and patterns of circular polarization from four-leaf to bell-like-with-inversion.
Commentaires: 5 pages text, 3 figures + 12 pages supplemental information, 3 movies
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Long coherence time of isolated Mn spin in CdTe revealed by pump-probe experiment
Auteur(s): Andreev S. , Cronenberger S., Scalbert D., Vladimirova M.
Conference: International School on Spin Optronics (ISSO 2) (Saint Pétersbourg, RU, 2012-07-10)
Ref HAL: hal-00816110_v1
Exporter : BibTex | endNote
Résumé: We report time-resolved Kerr rotation experiments on bulk CdMnTe with very low Mn concentration. We observe spin beatings which are the result of a complex spin dynamics of the d-electrons in the hyperfine field of their nucleus and the tetragonal crystal field. We find the transverse Mn spin relaxation time to increase with the increase of the effective temperature of Mn subsystem. At higher temperatures we measure T2 up to 12 ns, which is much longer than any previously measured values.
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Fine and hyperfine structure of isolated Mn in CdTe revealed by pump-probe experiments
Auteur(s): Andreev S., Cronenberger S., Vladimirova M., Scalbert D., Nawrocki Michal
Conference: International Conference on the Physics of Semiconductors (Zurich, CH, 2012-07-29)
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Faraday rotation induced by spin polarized electrons and nuclei in n-GaAs microcavity
Auteur(s): Giri R., Cronenberger S., Vladimirova M., Scalbert D., Kavokin Kirill, Lemaitre Aristide, Bloch Jacqueline
Conference: Internationale COnference on the physics of semiconductors (Zurich, CH, 2012-07-29)
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Optical Pump-Probe Detection of Manganese Hyperfine Beats in (Cd,Mn)Te Crystals
Auteur(s): Cronenberger S., Vladimirova M., Andreev S., Lifshits M., Scalbert D.
(Article) Publié:
Physical Review Letters, vol. 110 p.077403 (2013)
Ref HAL: hal-00789507_v1
DOI: 10.1103/PhysRevLett.110.077403
WoS: 000314871300011
Exporter : BibTex | endNote
16 Citations
Résumé: Optical pump-probe experiments reveal spin beats of manganese ions in (Cd,Mn)Te, due to hyperfine and crystal fields. At "magic" orientations of the magnetic field, the effect of local crystal field is strongly suppressed. In this case, the spin precession of Mn2+ embedded in the lattice approaches the precession expected for the free ion. Following optical excitation, regular spin pulses show up, revealing the one-to-one correspondence between precession frequency and Mn2+ nuclear spin state. The period of the spin pulses accurately determines the hyperfine constant |A|=705 neV. The manganese spin coherence time up to T2Mn≃15 ns is measured for a manganese concentration x=0.0011.
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