Nonequilibrium dynamics and fluctuation-dissipation relation in a sheared fluid

By Ludovic Berthier, J. Barrat. 2001

206 citations recorded by the source corpus.

The nonequilibrium dynamics of a binary Lennard-Jones mixture in a simple shear flow is investigated by means of molecular dynamics simulations. The range of temperature T investigated covers both the liquid, supercooled, and glassy states, while the shear rate γ covers both the linear and nonlinear regimes of rheology. The results can be interpreted in the context of a nonequilibrium, schematic mode-coupling theory developed recently, which makes the theory applicable to a wide range of soft glassy materials. The behavior of the viscosity η(T,γ) is first investigated. In the nonlinear regime, strong shear-thinning is obtained, η∼γ−α(T), with α(T)≃23 in the supercooled regime. Scaling properties of the intermediate scattering functions are studied. Standard “mode-coupling properties” of factorization and time superposition hold in this nonequilibrium situation. The fluctuation-dissipation relation is violated in the shear flow in a way very similar to that predicted theoretically, allowing for the definit...

Subfields: Biomedical Engineering, Condensed Matter Physics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/7ce2c2fcb1c8293b27bda2b0d5a7c5b2752fd224

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Citations in the corpus

Theoretical perspective on the glass transition and amorphous materials (2010, methodology): “…is well-known and commonly found in the rheology literature (Larson, 1999), and these predictions compare rather well with computer simulations (Yamamoto and Onuki, 1998b; Barrat and Berthier, 2001b; Berthier and Barrat, 2002b), and experiments (Crassous et al., 2006; Besseling et al., 2007).”
Mechanical rejuvenation in polymer glasses: fact or fallacy? (2003, background): “One reason that a full understanding of this observation is important arises from the continued use of similar power-law dependences to describe ageing phenomena in other systems such as spin glasses and ‘shear melted’ pastes or colloidal glasses and then making analogies to the structural glass sys”
Stochastic thermodynamics, fluctuation theorems and molecular machines (2012, methodology): “g, [334, 335] for a binary Lennard-Jones mixture in a simple shear flow, [336] for a glassy model system, [337, 338, 339, 340] for simple interacting model systems, [341, 342, 343] for simple Langevin systems, and [344] for field-theoretical models.”
The effective temperature (2011, background): “In [120], the molecular dynamics of a binary Lennard–Jones mixture under a steady and homogeneous shear flow was studied.”
Homogeneous non-equilibrium molecular dynamics simulations of viscous flow: techniques and applications (2007, background): “…properties of glassy shearing fluids and examination of fluctuation-dissipation relation Barrat and Berthier (2000), Berthier et al. (2000), Berthier and Barrat (2002) [152–154] Non-equilibrium thermodynamics Steady-state thermodynamics of shearing fluids Evans and Hanley (1980), Daivis…”
Slow dynamics in glassy soft matter (2005, background): “On the other hand, simulation works on a binary LennardJones mixture [131] have shown that the effective temperature is independent of the chosen observable, while it has been shown theoretically [132] that the effective temperature does depend on the observable in the glass phase of Bouchaud’s trap”
Modeling the mechanics of amorphous solids at different length scale and time scale (2011, background): “[22, 23] and model foams [184] are comparable to those in equilibrium systems maintained at an effective temperature higher than the true temperature and function of the shear rate.”