Accueil >
Production scientifique
Dynamique et rhéologie des fluides complexes (gels, polymères, mousses, colloïdes)
(36) Production(s) de l'année 2019
|
|
Can the glass transition be explained without a growing static length scale?
Auteur(s): Berthier L., Biroli Giulio, Bouchaud Jean-Philippe, Tarjus Gilles
(Article) Publié:
The Journal Of Chemical Physics, vol. 150 p.094501 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02082177_v1
Ref Arxiv: 1805.12378
DOI: 10.1063/1.5086509
WoS: 000460786600023
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
19 Citations
Résumé: It was recently discovered that SWAP, a Monte Carlo algorithm that involves the exchange of pairs of particles of differing diameters, can dramatically accelerate the equilibration of simulated supercooled liquids in regimes where the normal dynamics is glassy. This spectacular effect was subsequently interpreted as direct evidence against a static, cooperative explanation of the glass transition such as the one offered by the random first-order transition (RFOT) theory. We review several empirical facts that support the opposite view, namely, that a local mechanism cannot explain the glass transition phenomenology. We explain the speedup induced by SWAP within the framework of the RFOT theory. We suggest that the efficiency of SWAP stems from a postponed onset of glassy dynamics, which allows the efficient exploration of configuration space even in the regime where the physical dynamics is dominated by activated events across free-energy barriers. We describe this effect in terms of `crumbling metastability' and use the example of nucleation to illustrate the possibility of circumventing free-energy barriers of thermodynamic origin by a change of the local dynamical rules.
Commentaires: 15 pages, 3 figures; v2: improved discussions and clarifications
|
|
|
Bypassing sluggishness: SWAP algorithm and glassiness in high dimensions
Auteur(s): Berthier L., Charbonneau Patrick, Kundu Joyjit
(Article) Publié:
Physical Review E: Statistical, Nonlinear, And Soft Matter Physics, vol. p.031301 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02074910_v1
Ref Arxiv: 1810.06950
DOI: 10.1103/PhysRevE.99.031301
WoS: 000460663400001
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
8 Citations
Résumé: The recent implementation of a swap Monte Carlo algorithm (SWAP) for polydisperse mixtures fully bypasses computational sluggishness and closes the gap between experimental and simulation timescales in physical dimensions $d=2$ and $3$. Here, we consider suitably optimized systems in $d=2, 3,\dots, 8$, to obtain insights into the performance and underlying physics of SWAP. We show that the speedup obtained decays rapidly with increasing the dimension. SWAP nonetheless delays systematically the onset of the activated dynamics by an amount that remains finite in the limit $d \to \infty$. This shows that the glassy dynamics in high dimensions $d>3$ is now computationally accessible using SWAP, thus opening the door for the systematic consideration of finite-dimensional deviations from the mean-field description.
Commentaires: Réf Journal: Phys. Rev. E 99, 031301 (2019)
|
|
|
Marginally stable phases in mean-field structural glasses
Auteur(s): Scalliet C., Berthier L., Zamponi Francesco
(Article) Publié:
Physical Review E, vol. 99 p.012107 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-02022558_v1
Ref Arxiv: 1810.01213
DOI: 10.1103/PhysRevE.99.012107
WoS: WOS:000455062400003
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
11 Citations
Résumé: A novel form of amorphous matter characterized by marginal stability was recently discovered in the mean-field theory of structural glasses. Using this approach, we provide complete phase diagrams delimiting the location of the marginally stable glass phase for a large variety of pair interactions and physical conditions, extensively exploring physical regimes relevant to granular matter, foams, emulsions, hard and soft colloids, and molecular glasses. We find that all types of glasses may become marginally stable, but the extent of the marginally stable phase highly depends on the preparation protocol. Our results suggest that marginal phases should be observable for colloidal and non-Brownian particles near jamming and for poorly annealed glasses. For well-annealed glasses, two distinct marginal phases are predicted. Our study unifies previous results on marginal stability in mean-field models and will be useful to guide numerical simulations and experiments aimed at detecting marginal stability in finite-dimensional amorphous materials.
|
|
|
How glasses break: A randomcritical point for yielding
Auteur(s): Berthier L.
Conférence invité: Avalanche dynamics and precursors of catastrophic events (Les Houches, FR, 2019-02-04)
|
|
|
Low-frequency vibrational modes of stable glasses
Auteur(s): Wang Lijin, Ninarello A. S., Guan Pengfei, Berthier L., Szamel G., Flenner Elijah
(Article) Publié:
Nature Communications, vol. 10 p.26 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-01993807_v1
Ref Arxiv: 1804.08765
DOI: 10.1038/s41467-018-07978-1
WoS: 000454756900003
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
41 Citations
Résumé: We numerically study the evolution of the vibrational density of states $D(\omega)$ of zero-temperature glasses when their kinetic stability is varied over an extremely broad range, ranging from poorly annealed glasses obtained by instantaneous quenches from above the onset temperature, to ultrastable glasses obtained by quenching systems thermalised below the experimental glass temperature. The low-frequency part of the density of states splits between extended and quasi-localized modes. Extended modes exhibit a boson peak crossing over to Debye behaviour ($D(\omega) \sim \omega^2$) at low-frequency, with a strong correlation between the two regimes. Quasi-localized modes instead obey $D(\omega) \sim \omega^4$, irrespective of the glass stability. However, the prefactor of this quartic law becomes smaller in more stable glasses, and the corresponding modes become more localized and sparser. Our work is the first numerical observation of quasi-localized modes in a regime relevant to experiments, and it establishes a direct connection between glass stability and soft vibrational motion in amorphous solids.
Commentaires: 8 pages, 6 figures.Nat. Commun. 10, 26 (2019), https://rdcu.be/bfkWJ
|
|
|
Probing shear-induced rearrangements in Fourier space. I. Dynamic light scattering
Auteur(s): Aime S., Cipelletti L.
(Article) Publié:
Soft Matter, vol. 15 p.200-212 (2019)
Texte intégral en Openaccess :
Ref HAL: hal-01982836_v1
DOI: 10.1039/c8sm01563e
WoS: WOS:000454947400016
Exporter : BibTex | endNote
5 Citations
Résumé: Understanding the microscopic origin of the rheological behavior of soft matter is a long-lastingendeavour. While early efforts concentrated mainly on the relationship between rheology and structure,current research focuses on the role of microscopic dynamics. We present in two companion papers athorough discussion of how Fourier space-based methods may be coupled to rheology to shed light onthe relationship between the microscopic dynamics and the mechanical response of soft systems. In thisfirst companion paper, we report a theoretical, numerical and experimental investigation of dynamiclight scattering coupled to rheology. While in ideal solids and simple viscous fluids the displacement fieldunder a shear deformation is purely affine, additional non-affine displacements arise in many situationsof great interest, for example in elastically heterogeneous materials or due to plastic rearrangements.We show how affine and non-affine displacements can be separately resolved by dynamic lightscattering, and discuss in detail the effect of several non-idealities in typical experiments.
|