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Montpellier, France

Berthier L.,CNRS Charles Coulomb Laboratory | Kurchan J.,ESPCI ParisTech
Nature Physics | Year: 2013

The glass transition, extensively studied in dense fluids, polymers or colloids, corresponds to a marked evolution of equilibrium transport coefficients on a modest change of control parameter, such as temperature or pressure. A similar phenomenology is found in many systems evolving far from equilibrium, such as driven granular media, active and living matter. Although many theories compete to describe the glass transition at thermal equilibrium, very little is understood far from equilibrium. Here, we solve the dynamics of a specific, yet representative, class of glass models in the presence of non-thermal driving forces and energy dissipation, and show that a dynamic arrest can take place in these non-equilibrium conditions. Whereas the location of the transition depends on the specifics of the driving mechanisms, important features of the glassy dynamics are insensitive to details, suggesting that an effective thermal dynamics generically emerges at long timescales in non-equilibrium systems close to dynamic arrest. © 2013 Macmillan Publishers Limited. All rights reserved. Source

Berthier L.,CNRS Charles Coulomb Laboratory | Biroli G.,CEA Saclay Nuclear Research Center | Biroli G.,French National Center for Scientific Research
Reviews of Modern Physics | Year: 2011

A theoretical perspective is provided on the glass transition in molecular liquids at thermal equilibrium, on the spatially heterogeneous and aging dynamics of disordered materials, and on the rheology of soft glassy materials. We start with a broad introduction to the field and emphasize its connections with other subjects and its relevance. The important role played by computer simulations in studying and understanding the dynamics of systems close to the glass transition at the molecular level is given. The recent progress on the subject of the spatially heterogeneous dynamics that characterizes structural relaxation in materials with slow dynamics is reviewed. The main theoretical approaches are presented describing the glass transition in supercooled liquids, focusing on theories that have a microscopic, statistical mechanics basis. We describe both successes and failures and critically assess the current status of each of these approaches. The physics of aging dynamics in disordered materials and the rheology of soft glassy materials are then discussed, and recent theoretical progress is described. For each section, an extensive overview is given of the most recent advances, but we also describe in some detail the important open problems that will occupy a central place in this field in the coming years. © 2011 American Physical Society. Source

Berthier L.,CNRS Charles Coulomb Laboratory
Physical Review Letters | Year: 2014

We analyze the collective dynamics of self-propelled particles in the large-density regime where passive particles undergo a kinetic arrest to an amorphous glassy state. We capture the competition between self-propulsion and crowding effects using a two-dimensional model of self-propelled hard disks, which we study using Monte Carlo simulations. Although the activity drives the system far from equilibrium, self-propelled particles undergo a kinetic arrest, which we characterize in detail and compare with its equilibrium counterpart. In particular, the critical density for dynamic arrest continuously shifts to larger densities with increasing activity, and the relaxation time is surprisingly well described by an algebraic divergence resulting from the emergence of highly collective dynamics. These results show that dense assemblies of active particles undergo a nonequilibrium glass transition that is profoundly affected by self-propulsion mechanisms. © 2014 American Physical Society. Source

Crampe N.,CNRS Charles Coulomb Laboratory
Journal of Physics A: Mathematical and Theoretical | Year: 2015

We study the one-dimensional totally asymmetric simple exclusion process in contact with two reservoirs including also a fugacity at one boundary. The eigenvectors and the eigenvalues of the corresponding Markov matrix are computed using the modified algebraic Bethe ansatz, a method introduced recently to study the spin chain with non-diagonal boundaries. We provide in this case a proof of this method. © 2015 IOP Publishing Ltd. Source

Berthier L.,CNRS Charles Coulomb Laboratory
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

We analyze numerically thermal fluctuations of the static overlap between equilibrium configurations in a glass-forming liquid approaching the glass transition. We find that the emergence of slow dynamics near the onset temperature correlates with the development of non-Gaussian probability distributions of overlap fluctuations, measured using both annealed and quenched definitions. Below a critical temperature, a thermodynamic field conjugate to the overlap induces a first-order phase transition, whose existence we numerically demonstrate in the annealed case. These results establish that the approach to the glass transition is accompanied by profound changes in the nature of thermodynamic fluctuations, deconstructing the view that glassy dynamics occurs with little structural evolution. © 2013 American Physical Society. Source

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