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Physique Statistique
(54) Production(s) de l'année 2017
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Absence of Marginal Stability in a Structural Glass
Auteur(s): Scalliet C., Berthier L., Zamponi Francesco
(Article) Publié:
Physical Review Letters, vol. p.205501 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01636806_v1
Ref Arxiv: 1706.04112
DOI: 10.1103/PhysRevLett.119.205501
WoS: 000415173500010
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
31 Citations
Résumé: Marginally stable solids have peculiar physical properties that were discovered and analyzed in the context of the jamming transition. We theoretically investigate the existence of marginal stability in a prototypical model for structural glass-formers, combining analytical calculations in infinite dimensions to computer simulations in three dimensions. While mean-field theory predicts the existence of a Gardner phase transition towards a marginally stable glass phase at low temperatures, simulations show no hint of diverging timescales or lengthscales, but reveal instead the presence of sparse localized defects. Our results suggest that the Gardner transition is deeply affected by finite dimensional fluctuations, and raise issues about the relevance of marginal stability in structural glasses far away from jamming.
Commentaires: 5 pages, 3 figures. Réf Journal: Phys. Rev. Lett. 119, 205501 (2017)
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Configurational entropy measurements in extremely supercooled liquids that break the glass ceiling
Auteur(s): Berthier L., Charbonneau Patrick, Coslovich D., Ninarello A. S., Ozawa M., Yaida Sho
(Article) Publié:
Proceedings Of The National Academy Of Sciences Of The United States Of America, vol. 114 p.11356 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01630755_v1
Ref Arxiv: 1704.08257
DOI: 10.1073/pnas.1706860114
WoS: 000413520700049
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
47 Citations
Résumé: Liquids relax extremely slowly upon approaching the glass state. One explanation is that an entropy crisis, due to the rarefaction of available states, makes it increasingly arduous to reach equilibrium in that regime. Validating this scenario is challenging, because experiments offer limited resolution, while numerical studies lag more than eight orders of magnitude behind experimentally-relevant timescales. In this work we not only close the colossal gap between experiments and simulations but manage to create in-silico configurations that have no experimental analog yet. Deploying a range of computational tools, we obtain four estimates of their configurational entropy. These measurements consistently confirm that the steep entropy decrease observed in experiments is also found in simulations, even beyond the experimental glass transition. Our numerical results thus extend the new observational window into the physics of glasses and reinforce the relevance of an entropy crisis for understanding their formation.
Commentaires: 4+23 pages, 3+12 figures; v2: final version, with various changes made. Data relevant to this work can be accessed at http://dx.doi.org/10.7924/G8ZG6Q9T. Réf Journal: PNAS 114, 11356-11361 (2017)
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Bimodal distribution of Si-O-Si angles in sodo-silicate glasses
Auteur(s): Hehlen B., Neuville D. R., Kilymis D., Ispas S.
(Article) Publié:
Journal Of Non-Crystalline Solids, vol. 469 p.39-44 (2017)
Ref HAL: hal-01624760_v1
DOI: 10.1016/j.jnoncrysol.2017.04.009
WoS: WOS:000405882900007
Exporter : BibTex | endNote
6 Citations
Résumé: Polarized Raman scattering is performed in a series of sodo-silicate glasses. The Si–O–Si inter-tetrahedral angle and its distribution are extracted using a model developed previously for densified silica, and the result are compared to ab initio atomistic calculations. The two techniques reveal a reduction of the most probable angle of about 0.30°/mol% of Na2O, but the shape of the angular distributions are different. The results suggest that Raman scattering enhances a specific angular distribution of Si–O–Si bridges, likely those close to sodium atoms, highlighting local angular heterogeneities.
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Equilibrium simulations of supercooled liquids beyond laboratory time scales
Auteur(s): Coslovich D.
(Séminaires)
HH Wills Physics Laboratory (Bristol, GB), 2017-02-08 |
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Probing the laboratory glass transition with swap Monte Carlo simulations
Auteur(s): Coslovich D.
Conférence invité: Workshop on Glass Transition and Active Matter (Strasbourg, FR, 2017-10-06)
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Yield Stress Materials in Soft Condensed Matter
Auteur(s): Bonn Daniel, Denn Morton M., Berthier L., Divoux Thibaut, Manneville Sébastien
(Article) Publié:
Reviews Of Modern Physics, vol. 89 p.035005 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01589027_v1
Ref Arxiv: 1502.05281
DOI: 10.1103/RevModPhys.89.035005
WoS: 000407999000001
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
193 Citations
Résumé: We present a comprehensive review of the physical behavior of yield stress materials in soft condensed matter, which encompass a broad range of materials from colloidal assemblies and gels to emulsions and non-Brownian suspensions. All these disordered materials display a nonlinear flow behavior in response to external mechanical forces, due to the existence of a finite force threshold for flow to occur: the yield stress. We discuss both the physical origin and rheological consequences associated with this nonlinear behavior, and give an overview of experimental techniques available to measure the yield stress. We discuss recent progress concerning a microscopic theoretical description of the flow dynamics of yield stress materials, emphasizing in particular the role played by relaxation time scales, the interplay between shear flow and aging behavior, the existence of inhomogeneous shear flows and shear bands, wall slip, and non-local effects in confined geometries.
Commentaires: Review article: V1: 58 pages, 38 figs, 487 refs. V2: Final version 44 pages, 27 figs, 449 refs. Accepted for publication in Rev. Mod. Phys. Réf Journal: Rev. Mod. Phys. 89, 035005 (2017)
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Gene length as a regulator for ribosome recruitment and protein synthesis: theoretical insights
Auteur(s): Dias fernandes Lucas, De Moura Alessandro, Ciandrini L.
(Article) Publié:
Scientific Reports, vol. 7 p.17409 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01585262_v1
DOI: 10.1038/s41598-017-17618-1
WoS: 000417689400033
Exporter : BibTex | endNote
14 Citations
Résumé: Protein synthesis rates are determined, at the translational level, by properties of the transcript's sequence. The efficiency of an mRNA can be tuned by varying the ribosome binding sites controlling the recruitment of the ribosomes, or the codon usage establishing the speed of protein elongation.In this work we propose transcript length as a further key determinant of translation efficiency. Based on a physical model that considers the kinetics of ribosomes advancing on the mRNA and diffusing in its surrounding, as well as mRNA circularisation and ribosome drop-off, we explain how the transcript length may play a central role in establishing ribosome recruitment and the overall translation rate of an mRNA. According to our results, the proximity of the 3' end to the ribosomal recruitment site of the mRNA could induce a feedback in the translation process that would favour the recycling of ribosomes.We also demonstrate how this process may be involved in shaping the experimental ribosome density-gene length dependence. Finally, we argue that cells could exploit this mechanism to adjust and balance the usage of its ribosomal resources.
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