article · 15/03/2016
Nonlinear response and emerging nonequilibrium microstructures for biased diffusion in confined crowded environments
Résumé
We study analytically the dynamics and the microstructural changes of a host medium caused by a driven tracer particle moving in a confined, quiescent molecular crowding environment. Imitating typical settings of active microrheology experiments, we consider here a minimal model comprising a geometrically confined lattice system (a two-dimensional striplike or a three-dimensional capillary-like system) populated by two types of hard-core particles with stochastic dynamics (a tracer particle driven by a constant external force and bath particles moving completely at random). Resorting to a decoupling scheme, which permits us to go beyond the linear-response approximation (Stokes regime) for arbitrary densities of the lattice gas particles, we determine the force-velocity relation for the tracer particle and the stationary density profiles of the host medium particles around it. These results are validated a posteriori by extensive numerical simulations for a wide range of parameters. Our theoretical analysis reveals two striking features: (a) We show that, under certain conditions, the terminal velocity of the driven tracer particle is a nonmonotonic function of the force, so in some parameter range the differential mobility becomes negative, and (b) the biased particle drives the whole system into a nonequilibrium steady state with a stationary particle density profile past the tracer, which decays exponentially, in sharp contrast with the behavior observed for unbounded lattices, where an algebraic decay is known to take place.
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Benichou, O., Illien, P., Oshanin, G., Sarracino, A., & Voituriez, R. (2016). Nonlinear response and emerging nonequilibrium microstructures for biased diffusion in confined crowded environments. PHYSICAL REVIEW E, 93(3). https://doi.org/10.1103/PhysRevE.93.032128@article{Benichou2016_177,
author = {Benichou, O. and Illien, P. and Oshanin, G. and Sarracino, A. and Voituriez, R.},
year = {2016},
month = {3},
title = {Nonlinear response and emerging nonequilibrium microstructures for biased diffusion in confined crowded environments},
journal = {PHYSICAL REVIEW E},
volume = {93},
number = {3},
abstract = {We study analytically the dynamics and the microstructural changes of a host medium caused by a driven tracer particle moving in a confined, quiescent molecular crowding environment. Imitating typical settings of active microrheology experiments, we consider here a minimal model comprising a geometrically confined lattice system (a two-dimensional striplike or a three-dimensional capillary-like system) populated by two types of hard-core particles with stochastic dynamics (a tracer particle driven by a constant external force and bath particles moving completely at random). Resorting to a decoupling scheme, which permits us to go beyond the linear-response approximation (Stokes regime) for arbitrary densities of the lattice gas particles, we determine the force-velocity relation for the tracer particle and the stationary density profiles of the host medium particles around it. These results are validated a posteriori by extensive numerical simulations for a wide range of parameters. Our theoretical analysis reveals two striking features: (a) We show that, under certain conditions, the terminal velocity of the driven tracer particle is a nonmonotonic function of the force, so in some parameter range the differential mobility becomes negative, and (b) the biased particle drives the whole system into a nonequilibrium steady state with a stationary particle density profile past the tracer, which decays exponentially, in sharp contrast with the behavior observed for unbounded lattices, where an algebraic decay is known to take place.},
url = {http://www.dx.doi.org/10.1103/PhysRevE.93.032128},
doi = {10.1103/PhysRevE.93.032128},
issn = {2470-0045},
}TY - JOUR
AU - Benichou, O.
AU - Illien, P.
AU - Oshanin, G.
AU - Sarracino, A.
AU - Voituriez, R.
PY - 2016
DA - 2016/03/15
TI - Nonlinear response and emerging nonequilibrium microstructures for biased diffusion in confined crowded environments
JO - PHYSICAL REVIEW E
VL - 93
IS - 3
SN - 2470-0045
AB - We study analytically the dynamics and the microstructural changes of a host medium caused by a driven tracer particle moving in a confined, quiescent molecular crowding environment. Imitating typical settings of active microrheology experiments, we consider here a minimal model comprising a geometrically confined lattice system (a two-dimensional striplike or a three-dimensional capillary-like system) populated by two types of hard-core particles with stochastic dynamics (a tracer particle driven by a constant external force and bath particles moving completely at random). Resorting to a decoupling scheme, which permits us to go beyond the linear-response approximation (Stokes regime) for arbitrary densities of the lattice gas particles, we determine the force-velocity relation for the tracer particle and the stationary density profiles of the host medium particles around it. These results are validated a posteriori by extensive numerical simulations for a wide range of parameters. Our theoretical analysis reveals two striking features: (a) We show that, under certain conditions, the terminal velocity of the driven tracer particle is a nonmonotonic function of the force, so in some parameter range the differential mobility becomes negative, and (b) the biased particle drives the whole system into a nonequilibrium steady state with a stationary particle density profile past the tracer, which decays exponentially, in sharp contrast with the behavior observed for unbounded lattices, where an algebraic decay is known to take place.
DO - 10.1103/PhysRevE.93.032128
UR - http://www.dx.doi.org/10.1103/PhysRevE.93.032128
ER -