title: Universality and nonuniversality of mobility in heterogeneous single-file systems and Rouse chains.
abstract: We study analytically the tracer particle mobility in single-file systems with distributed friction constants. Our system serves as a prototype for nonequilibrium, heterogeneous, strongly interacting Brownian systems. The long time dynamics for such a single-file setup belongs to the same universality class as the Rouse model with dissimilar beads. The friction constants are drawn from a density ϱ(ξ), and we derive an asymptotically exact solution for the mobility distribution P[μ0(s)], where μ0(s) is the Laplace-space mobility. If ϱ is light tailed (first moment exists), we find a self-averaging behavior: P[μ0(s)]=δ[μ0(s)-μ(s)], with μ(s)∝s1/2. When ϱ(ξ) is heavy tailed, ϱ(ξ)≃ξ-1-α(0<α<1) for large ξ, we obtain moments 〈[μs(0)]n〉∝sβn, where β=1/(1+α) and there is no self-averaging. The results are corroborated by simulations.
authors.affiliation: MEMPHYS-Center for Biomembrane Physics, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Lomholt
authors.affiliation: Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, SE-223 62 Lund, Sweden.
authors.forename: Tobias
authors.initials: T
authors.lastname: Ambjörnsson