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(295) Production(s) de l'année 2019
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Experimental Observation of Temperature-Driven Topological Phase Transition in HgTe/CdHgTe Quantum Wells
Auteur(s): Zholudev M., Kadykov A., Fadeev Mikhail, Marcinkiewicz M., Ruffenach S., Consejo C., Knap W., Torres Jérémie, Morozov Sergey, Gavrilenko Vladimir, Mikhailov Nikolay, Dvoretskii Sergey, Teppe F.
(Article) Publié:
Condensed Matter, vol. 4 p.27 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02072773_v1
DOI: 10.3390/condmat4010027
WoS: 000464288500001
Exporter : BibTex | endNote
1 Citation
Résumé: We report on the comparison between temperature-dependent magneto-absorption and magnetotransport spectroscopy of HgTe/CdHgTe quantum wells in terms of the detection of the phase transition between the topological insulator and band insulator states. Our results demonstrate that temperature-dependent magnetospectroscopy is a powerful tool to discriminate trivial and topological insulator phases, yet the magnetotransport method is shown to have advantages for the clear manifestation of the phase transition with accurate quantitative values of the transition parameter (i.e., critical magnetic field B c).
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Surfing on protein waves: proteophoresis as a mechanism for bacterial genome partitioning
Auteur(s): Walter J.-C.
Conference: APS March Meeting 2019 (Boston, US, 2019-03-04)
Texte intégral en Openaccess :
Ref HAL: hal-02064951_v1
Exporter : BibTex | endNote
Résumé: Efficient bacterial chromosome segregation typically requires the coordinated action of a three-component, fueled by adenosine triphosphate machinery called the partition complex. We present a phenomenological model accounting for the dynamic activity of this system that is also relevant for the physics of catalytic particles in active environments. The model is obtained by coupling simple linear reaction-diffusion equations with a proteophoresis, or “volumetric” chemophoresis, force field that arises from protein-protein interactions and provides a physically viable mechanism for complex translocation. This minimal description captures most known experimental observations: dynamic oscillations of complex components, complex separation and subsequent symmetrical positioning. The predictions of our model are in phenomenological agreement with and provide substantial insight into recent experiments. From a non-linear physics view point, this system explores the active separation of matter at micrometric scales with a dynamical instability between static positioning and travelling wave regimes triggered by the dynamical spontaneous breaking of rotational symmetry.Walter J.-C. et al (2017) Phys. Rev. Lett. 119, 028101.*ANR IBM (ANR-14-CE09-0025-01), ANR-10-LABX-0020 and Labex NUMEV
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Inferring data on cilia spatiotemporal coordination through bronchial epithelium imaging
Auteur(s): Jory M., Fort Aurélie, Casanellas Vilageliu L., Vachier Isabelle, Bourdin Arnaud, Massiera G.
(Affiches/Poster)
Physics and Physiology of Motile Cilia (Bad Honnef, DE), 2019-01-27
Ref HAL: hal-02061766_v1
Exporter : BibTex | endNote
Résumé: The mucociliary function of the bronchial epithelium ensures the continuous clearance of the respiratory system. This function relies on two main elements: mucus properties and cilia beating coordination. We work on high speed optical microscopy videos of Human bronchial epithelium from ALI (Air-liquid interface) cultures. We present here a technique based on the tracking of each cilium and on the spatiotemporal analysis of the obtained trajectories. To relate each cilium to its corresponding cell, a clustering method is used. The spatiotemporal coordination can than be quantified both, inside and in-between ciliated cells. In addition the physical parameters can be mapped to observe the heterogeneity of the cilia activity and compare different pathologies.
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Competition between horizontal and vertical polariton lasing in planar microcavities
Auteur(s): Jamadi O., Réveret F., Solnyshkov D., Disseix P., Leymarie J., Mallet-Dida L.
(Article) Publié:
Physical Review B, vol. 99 p.085304 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02059958_v1
DOI: 10.1103/PhysRevB.99.085304
WoS: WOS:000458367800009
Exporter : BibTex | endNote
1 Citation
Résumé: Planar microcavities filled with active materials containing excitonic resonances host radiative exciton-polariton (polariton) modes with in-plane wave vectors within the light cone. They also host at least one mode that is guided in the cavity plane by total internal reflection and that is not radiatively coupled to the vacuum modes except through defects or sample edges. We show that polariton lasing mediated by polariton stimulated scattering can occur concomitantly in both types of modes in a microcavity. By adjusting the detuning between the exciton and the radiative photon mode one can favor polariton lasing either in the radiative or in the guided modes. Our results suggest that the competition between these two types of polariton lasing modes may have played a role in many previous observations of polariton lasing and polariton Bose-Einstein condensation.
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Optimizing the shape of InAs/InP quantum dot-nanowires grown by MBE on silicon for efficient light sources emitting in the telecom band
Auteur(s): Jaffal Ali, Regreny Philippe, Redjem W., Nguyen Hai Son, Cueff Sébastien, Letartre Xavier, Patriarche Gilles, Rousseau E., Cassabois G., Gendry Michel, Chauvin Nicolas
Conference: 20th European Workshop on Molecular Beam Epitaxy (Lenggries, DE, 2019-02-17)
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Vibrational properties of sodosilicate glasses from first-principles calculations
Auteur(s): Kilymis D., Ispas S., Hehlen B., Peuget S., Delaye Jean-Marc
(Article) Publié:
Physical Review B, vol. 99 p.054209 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02043157_v1
DOI: 10.1103/PhysRevB.99.054209
WoS: 000459221700002
Exporter : BibTex | endNote
5 Citations
Résumé: The vibrational properties of three sodosilicate glasses have been investigated in the framework of density functional theory. The pure vibrational density of states has been calculated for all systems and the different vibrational modes have been assigned to specific atoms or structuralunits. It is shown that the Na content affects several vibrational features as the position and intensity of the R band or the mixing of the rocking and bending atomic motions of the Si-O-Si bridges. The calculated Raman spectra have been found to agree with experimental observations and their decomposition indicated the dominant character of the non-bridging oxygen contribution on the spectra, in particular for the high-frequency band, above 800 cm −1 . The decomposition of the high-frequency Raman feature into vibrations of the depolymerized tetrahedra (i.e. Q n -units) has revealed spectral shapes of the partial contributions that cannot be accounted for by simple Gaussians as frequently assumed in the treatment of experimentally obtained Raman spectra.
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Mucus Microrheology Measured on Human Bronchial Epithelium Culture
Auteur(s): Jory M., Bellouma Karim, Blanc C., Casanellas Vilageliu L., Petit Aurelie, Reynaud Paul, Vernisse Charlotte, Vachier Isabelle, Bourdin Arnaud, Massiera G.
(Article) Publié:
Frontiers In Physics, vol. 7 p.19 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02025486_v1
DOI: 10.3389/fphy.2019.00019
WoS: WOS:000459130800002
Exporter : BibTex | endNote
1 Citation
Résumé: We describe an original method to measure mucus microrheology on human bronchial epithelium culture using optical tweezers. We probed rheology on the whole thickness of mucus above the epithelium and showed that mucus gradually varies in rheological response, from an elastic behavior close to the epithelium to a viscous one far away. Microrheology was also performed on mucus collected on the culture, on ex vivo mucus collected by bronchoscopy, and on another epithelium model. Differences are discussed and are related to mucus heterogeneity, adhesiveness and collection method.
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