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(314) Production(s) de BERTHIER L.


Rejuvenation and Memory Effects in a Structural Glass
Auteur(s): Scalliet C., Berthier L.
(Article) Publié:
Physical Review Letters, vol. 122 p.255502 (2019)
Texte intégral en Openaccess :
Ref HAL: hal02180202_v1
PMID 31347855
DOI: 10.1103/PhysRevLett.122.255502
WoS: 000473139000011
Exporter : BibTex  endNote
21 Citations
Résumé: We show numerically that a threedimensional model for structural glass displays aging, rejuvenation, and memory effects when subjected to a temperature cycle. These effects indicate that the free energy landscape of structural glasses may possess the complex hierarchical structure that characterizes materials such as spin and polymer glasses. We use the theoretical concept of marginal stability to interpret our results, and explain in which physical conditions a complex aging dynamics can emerge in dense supercooled liquids, paving the way for future experimental studies of complex aging dynamics in colloidal and granular glasses.



Glassy dynamics in dense systems of active particles
Auteur(s): Berthier L., Flenner Elijah, Szamel G.
(Article) Publié:
The Journal Of Chemical Physics, vol. 150 p.200901 (2019)
Texte intégral en Openaccess :
Ref HAL: hal02162002_v1
Ref Arxiv: 1902.08580
DOI: 10.1063/1.5093240
WoS: WOS:000473301400001
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
15 Citations
Résumé: Despite the diversity of materials designated as active matter, virtually all active systems undergo a form of dynamic arrest when crowding and activity compete, reminiscent of the dynamic arrest observed in colloidal and molecular fluids undergoing a glass transition. We present a short perspective on recent and ongoing efforts to understand how activity competes with other physical interactions in dense systems. We first review recent experimental work on active materials that uncovered both classic signatures of glassy dynamics and intriguing novel phenomena at large density. We introduce a minimal model of selfpropelled particles where the competition between interparticle interactions, crowding, and selfpropulsion can be studied in great detail. We discuss more complex models that include some additional, materialspecific ingredients. We end with some general perspectives on dense active materials, suggesting directions for future research, in particular for theoretical work.
Commentaires: 16 pages, 8 figures. Réf Journal: J. Chem. Phys. 150, 200901 (2019)



Configurational entropy of glassforming liquids
Auteur(s): Berthier L., Ozawa M., Scalliet C.
(Article) Publié:
The Journal Of Chemical Physics, vol. 150 p.160902 (2019)
Texte intégral en Openaccess :
Ref HAL: hal02123889_v1
Ref Arxiv: 1902.07679
DOI: 10.1063/1.5091961
WoS: WOS:000466698700002
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
13 Citations
Résumé: The configurational entropy is one of the most important thermodynamic quantities characterizing supercooled liquids approaching the glass transition. Despite decades of experimental, theoretical, and computational investigation, a widely accepted definition of the configurational entropy is missing, its quantitative characterization remains fraud with difficulties, misconceptions and paradoxes, and its physical relevance is vividly debated. Motivated by recent computational progress, we offer a pedagogical perspective on the configurational entropy in glassforming liquids. We first explain why the configurational entropy has become a key quantity to describe glassy materials, from early empirical observations to modern theoretical treatments. We explain why practical measurements necessarily require approximations that make its physical interpretation delicate. We then demonstrate that computer simulations have become an invaluable tool to obtain precise, nonambiguous, and experimentallyrelevant measurements of the configurational entropy. We describe a panel of available computational tools, offering for each method a critical discussion. This perspective should be useful to both experimentalists and theoreticians interested in glassy materials and complex systems.
Commentaires: 20 pages, 11 figures, submitted to the Journal of Chemical Physics. Réf Journal: J. Chem. Phys. 150, 160902 (2019)



Zerotemperature glass transition in two dimensions
Auteur(s): Berthier L., Charbonneau Patrick, Ninarello A. S., Ozawa M., Yaida Sho
(Article) Publié:
Nature Communications, vol. 10 p.1508 (2019)
Texte intégral en Openaccess :
Ref HAL: hal02101358_v1
Ref Arxiv: 1805.09035
DOI: 10.1038/s41467019095123
WoS: 000463170600007
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
16 Citations
Résumé: The nature of the glass transition is theoretically understood in the meanfield limit of infinite spatial dimensions, but the problem remains totally open in physical dimensions. Nontrivial finitedimensional fluctuations are hard to control analytically, and experiments fail to provide conclusive evidence regarding the nature of the glass transition. Here, we use Monte Carlo simulations that fully bypass the glassy slowdown, and access equilibrium states in twodimensional glassforming liquids at low enough temperatures to directly probe the transition. We find that the liquid state terminates at a thermodynamic glass transition at zero temperature, which is associated with an entropy crisis and a diverging static correlation length.
Commentaires: 23 pages, 18 figures. Réf Journal: Nat. Commun. 10, 1508 (2019)



Hierarchical landscape of hard disk glasses
Auteur(s): Liao Qinyi, Berthier L.
(Article) Publié:
Physical Review X, vol. 9 p.011049 (2019)
Texte intégral en Openaccess :
Ref HAL: hal02092636_v1
Ref Arxiv: 1810.10256
DOI: 10.1103/PhysRevX.9.011049
WoS: 000461916500001
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
9 Citations
Résumé: We numerically analyse the landscape governing the evolution of the vibrational dynamics of hard disk glasses as the density increases towards jamming. We find that the dynamics becomes slow, spatially correlated, and starts to display aging dynamics across an avoided Gardner transition, with a phenomenology that resembles three dimensional observations. We carefully analyse the behaviour of single glass samples, and find that the emergence of aging dynamics is controlled by the apparition of a complex organisation of the landscape that splits into a remarkable hierarchy of minima as jamming is approached. Our results show that the meanfield prediction of a Gardner phase characterized by an ultrametric structure of the landscape provides a useful description of finite dimensional systems, even when the Gardner transition is avoided.



Can the glass transition be explained without a growing static length scale?
Auteur(s): Berthier L., Biroli Giulio, Bouchaud JeanPhilippe, Tarjus Gilles
(Article) Publié:
The Journal Of Chemical Physics, vol. 150 p.094501 (2019)
Texte intégral en Openaccess :
Ref HAL: hal02082177_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 firstorder 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 freeenergy barriers. We describe this effect in terms of `crumbling metastability' and use the example of nucleation to illustrate the possibility of circumventing freeenergy 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: hal02074910_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 finitedimensional deviations from the meanfield description.
Commentaires: Réf Journal: Phys. Rev. E 99, 031301 (2019)
