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Transition vitreuse, hétérogénéité dynamique et vieillissement dans les systèmes a dynamique lente
(49) Production(s) de l'année 2017
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Exploring the jamming transition over a wide range of critical densities 
Auteur(s): Ozawa M., Berthier L., Coslovich D.
(Article) Publié:
Scipost Physics, vol. 3 p.027 (2017)
Texte intégral en Openaccess : 
Ref HAL: hal-01685133_v1
Ref Arxiv: 1705.10156
DOI: 10.21468/SciPostPhys.3.4.027
WoS: WOS:000418511900002
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
15 Citations
Résumé: We numerically study the jamming transition of frictionless polydisperse spheres in three dimensions. We use an efficient thermalisation algorithm for the equilibrium hard sphere fluid and generate amorphous jammed packings over a range of critical jamming densities that is about three times broader than in previous studies. This allows us to reexamine a wide range of structural properties characterizing the jamming transition. Both isostaticity and the critical behavior of the pair correlation function hold over the entire range of jamming densities. At intermediate length scales, we find a weak, smooth increase of bond orientational order. By contrast, distorted icosahedral structures grow rapidly with increasing the volume fraction in both fluid and jammed states. Surprisingly, at large scale we observe that denser jammed states show stronger deviations from hyperuniformity, suggesting that the enhanced amorphous ordering inherited from the equilibrium fluid competes with, rather than enhances, hyperuniformity. Finally, finite size fluctuations of the critical jamming density are considerably suppressed in the denser jammed states, indicating an important change in the topography of the potential energy landscape. By considerably stretching the amplitude of the critical "J-line", our work disentangles physical properties at the contact scale that are associated with jamming criticality, from those occurring at larger length scales, which have a different nature.
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How active forces influence nonequilibrium glass transitions
Auteur(s): Berthier L., Flenner Elijah, Szamel G.
(Article) Publié:
New Journal Of Physics, vol. 19 p.125006 (2017)
Texte intégral en Openaccess :
Ref HAL: hal-01667079_v1
Ref Arxiv: 1708.04259
DOI: 10.1088/1367-2630/aa914e
WoS: 000424893800001
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
14 Citations
Résumé: Dense assemblies of self-propelled particles undergo a nonequilibrium form of glassy dynamics. Physical intuition suggests that increasing departure from equilibrium due to active forces fluidifies a glassy system. We falsify this belief by devising a model of self-propelled particles where increasing departure from equilibrium can both enhance or depress glassy dynamics, depending on the chosen state point. We analyze a number of static and dynamic observables and suggest that the location of the nonequilibrium glass transition is primarily controlled by the evolution of two-point static density correlations due to active forces. The dependence of the density correlations on the active forces varies non-trivially with the details of the system, and is difficult to predict theoretically. Our results emphasize the need to develop an accurate liquid state theory for nonequilibrium systems.
Commentaires: . Réf Journal: New J. Phys. 19, 125006 (2017)
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Granular materials flow like complex fluids
Auteur(s): Kou Binquan, Cao Yixin, Li Jindong, Xia Chengjie, Li Zhifeng, Dong Haipeng, Zhang Ang, Zhang Jie, Kob W. , Wang Yujie
(Article) Publié:
Nature, vol. 551 p.360 (2017)
Texte intégral en Openaccess :
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