Optique des états collectifs et des spins (OECS)
Responsable : Christelle Brimont
Membres actuels
ARISTEGUI Rémi (Doctorant)
BRETAGNON Thierry (Enseignant Chercheur)
BRIMONT Christelle (Enseignante Chercheuse)
CRONENBERGER Steeve (Enseignant Chercheur)
DEVELAY Valentin (Doctorant)
DOYENNETTE Laetitia (Enseignante Chercheuse)
GRIBAKIN Boris (Doctorant)
GUILLET Thierry (Enseignant Chercheur)
LEFEBVRE Pierre (Chercheur)
SCALBERT Denis (Chercheur)
VLADIMIROVA Maria (Chercheuse)
Domaines de Recherche
L’équipe "Optique des états collectifs et des spins (OECS)" développe son activité autour de 3 thèmes de recherche, en s’appuyant sur les plateformes expérimentales de l’axe PEPS.
Nos projets financés incluent :
Thèses en cours
- Rémi Aristégui (2021-2024) : Dipolar excitons hosted by nitride-based heterostructures for emerging quantum states
- Boris Gribakin (2021-2024), thèse en co-tutelle avec St-Petersburg University : Spin diffusion of electrons and excitons in semiconductors studied by spin noise and pump-probe spectroscopy
- Valentin Develay (2022-2025) : Waveguide polariton lasers
Thèses récentes
- Hassen Souissi (2020-2023) : Quantum fluids of light for integrated photonics : waveguide polariton devices
Nous rejoindre
Plusieurs possibilités de stages, thèses et post-doctorats sont offertes au sein des équipes, parmi lesquelles :
Dernières publications
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Molecular beam epitaxy of GaN/AlGaN quantum wells on bulk GaN substrate in the step-flow or step meandering regime: Influence on indirect exciton diffusion
Auteur(s): Damilano B., Aristégui R., Teisseyre H., Vézian S., Guigoz V., Courville A., Florea I., Vennéguès P., Bockowski M., Guillet T., Vladimirova M.
(Article) Publié:
Journal Of Applied Physics, vol. 135 p. (2024)
Texte intégral en Openaccess :
Ref HAL: hal-04489504_v1
Ref Arxiv: 2310.13323
DOI: 10.1063/5.0182659
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: GaN/AlxGa1−xN quantum wells were grown by molecular beam epitaxy on high quality bulk (0001) GaN substrates. The quantum well thickness was set in the 6–8 nm range to favor the photoluminescence emission of indirect excitons. Indeed, such excitons are known to be spatially indirect due to the presence of the internal electric field which spatially separates the electron and hole wave functions. The growth conditions were optimized in view of minimizing the photoluminescence peak broadening. In particular, the impact of growth temperature (up to 900 °C) on the surface morphology, structural, and photoluminescence properties was studied. The diffusion of indirect excitons on the scale of tens of micrometers was measured with a micro-photoluminescence setup equipped with a spatially resolved detection. A dedicated model and its analysis allow us to extract from these measurements the exciton diffusion constant and to conclude on the optimum growth conditions for the GaN/AlxGa1−xN quantum well structures suited for studies of quantum collective effects in indirect exciton liquids.
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Mode-locked waveguide polariton laser
Auteur(s): Souissi H., Gromovyi M., Septembre I., Develay V., Brimont C., Doyennette L., Cambril E., Bouchoule S., Alloing B., Frayssinet E., Zúñiga-Pérez J., Ackemann T., Malpuech G., Solnyshkov D., Guillet T.
(Article) Publié:
Optica, vol. 11 p.962 (2024)
Texte intégral en Openaccess :
Ref HAL: hal-04776451_v1
Ref Arxiv: 2310.18661
DOI: 10.1364/OPTICA.524753
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: So far, exciton-polariton (polariton) lasers were mostly single-mode lasers based on microcavities. Despite the large repulsive polariton-polariton interaction, a pulsed mode-locked polariton laser was never, to our knowledge, reported. Here, we use a 60-µm-long GaN-based waveguide surrounded by distributed Bragg reflectors forming a multi-mode horizontal cavity. We demonstrate experimentally and theoretically a polariton mode-locked micro-laser operating in the blue-UV, at room temperature, with a 300 GHz repetition rate and 100-fs-long pulses. The mode-locking is demonstrated by the compensation (linearization) of the mode dispersion by the self-phase modulation induced by the polariton-polariton interaction. It is also supported by the observation in experiment and theory of the typical envelope frequency profile of a bright soliton.
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Genuine and faux single G centers in carbon-implanted silicon
Auteur(s): Durand A., Baron Y., Cache F., Herzig Tobias, Khoury Mario, Pezzagna Sébastien, Meijer Jan, Hartmann Jean-Michel, Reboh Shay, Abbarchi Marco, Robert-Philip I., Gérard Jean-Michel, Jacques V., Cassabois G., Dréau A.
(Article) Publié:
Physical Review B, vol. 110 p.L020102 (2024)
Texte intégral en Openaccess :
Ref HAL: hal-04699426_v1
Ref Arxiv: 2402.07705
DOI: 10.1103/PhysRevB.110.L020102
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: Among the wide variety of single fluorescent defects investigated in silicon, numerous studies have focused on color centers with a zero-phonon line around 1.28 μm and identified to a common carbon complex in silicon, namely the G center. However, inconsistent estimates regarding their quantum efficiency cast doubt on the correct identification of these individual emitters. Through a comparative analysis of their single-photon emission properties, we demonstrate that these single color centers are split in two distinct families of point defects. A first family consists of the genuine single G centers with a well-identified microscopic structure and whose photoluminescence has been investigated on ensemble measurements since the 1960s. The remaining defects belong to another color center, which we will refer to as the G* center, whose atomic configuration has yet to be determined. These results provide a safeguard against future defect misidentifications, which is crucial for further development of quantum technologies relying on G or G* center quantum properties.
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