TY - JOUR
T1 - Derivation of a microscopic theory of barriers and activated hopping transport in glassy liquids and suspensions
AU - Schweizer, Kenneth S.
N1 - Funding Information:
I gratefully acknowledge helpful and stimulating discussions and/or correspondence with David Chandler, Juanpe Garrahan, Vladimir Kobelev, Erica Saltzman, and Grzegorz Szamel. I also thank Erica Saltzman for preparing the figure, and Grzegorz Szamel and Erica Saltzman for a critical reading of the manuscript and helpful comments. This work was supported by the Nanoscale Science and Engineering Initiative of the National Science Foundation under NSF Award No. DMR-0117792, and the U.S. Department of Energy, Division of Materials Sciences under Award No. DEFG02-91ER45439 through the UIUC Frederick Seitz Materials Research Laboratory.
PY - 2005
Y1 - 2005
N2 - A recently proposed microscopic activated barrier hopping theory [K. S. Schweizer and E. J. Saltzman, J. Chem. Phys. 119, 1181 (2003)] of slow single-particle dynamics in glassy liquids, suspensions, and gels is derived using nonequilibrium statistical mechanics. Fundamental elements underlying the stochastic nonlinear Langevin equation description include an inhomogeneous liquid or locally solid-state perspective, dynamic density-functional theory (DDFT), a local equilibrium closure, and a coarse-grained free-energy functional. A dynamic Gaussian approximation is not adopted which is the key for avoiding a kinetic ideal glass transition. The relevant excess free energy is of a nonequilibrium origin and is related to dynamic force correlations in the fluid. The simplicity of the approach allows external perturbations to be rather easily incorporated. Dynamic heterogeneity enters naturally via mobility fluctuations associated with the stochastic barrier-hopping process. The derivation both identifies the limitations of the theory and suggests new avenues for its systematic improvement. Comparisons with ideal mode-coupling theory, alternative DDFT approaches and a field theoretic path-integral formulation are presented.
AB - A recently proposed microscopic activated barrier hopping theory [K. S. Schweizer and E. J. Saltzman, J. Chem. Phys. 119, 1181 (2003)] of slow single-particle dynamics in glassy liquids, suspensions, and gels is derived using nonequilibrium statistical mechanics. Fundamental elements underlying the stochastic nonlinear Langevin equation description include an inhomogeneous liquid or locally solid-state perspective, dynamic density-functional theory (DDFT), a local equilibrium closure, and a coarse-grained free-energy functional. A dynamic Gaussian approximation is not adopted which is the key for avoiding a kinetic ideal glass transition. The relevant excess free energy is of a nonequilibrium origin and is related to dynamic force correlations in the fluid. The simplicity of the approach allows external perturbations to be rather easily incorporated. Dynamic heterogeneity enters naturally via mobility fluctuations associated with the stochastic barrier-hopping process. The derivation both identifies the limitations of the theory and suggests new avenues for its systematic improvement. Comparisons with ideal mode-coupling theory, alternative DDFT approaches and a field theoretic path-integral formulation are presented.
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U2 - 10.1063/1.2137701
DO - 10.1063/1.2137701
M3 - Article
C2 - 16396543
AN - SCOPUS:29744447935
SN - 0021-9606
VL - 123
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 24
M1 - 244501
ER -