Universal fluctuations of single-particle diffusivity in a quenched environment

Takuma Akimoto, Eli Barkai, Keiji Saito

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Local diffusion coefficients in disordered materials such as living cells are highly heterogeneous. We consider finite systems with quenched disorder in order to investigate the effects of sample disorder fluctuations and confinement on single-particle diffusivity. While the system is ergodic in a single disorder realization, the time-averaged mean square displacement depends crucially on the disorder; i.e., the system is ergodic but non-self-averaging. Moreover, we show that the disorder average of the time-averaged mean square displacement decreases with the system size. We find a universal distribution for diffusivity in the sense that the shape of the distribution does not depend on the dimension. Quantifying the degree of the non-self-averaging effect, we show that fluctuations of single-particle diffusivity far exceed the corresponding annealed theory and also find confinement effects. The relevance for experimental situations is also discussed.

Original languageEnglish
Article number180602
JournalPhysical Review Letters
Volume117
Issue number18
DOIs
StatePublished - 28 Oct 2016

Bibliographical note

Publisher Copyright:
© 2016 American Physical Society.

Funding

T. A. and K. S. were supported by JSPS KAKENHI Grants No. 26800204 and No. JP25103003, respectively. E. B. acknowledges the Israel Science Foundation.

FundersFunder number
Japan Society for the Promotion of ScienceJP25103003, 16KT0021, 26800204, 26400404, 16H02211
Israel Science Foundation

    Fingerprint

    Dive into the research topics of 'Universal fluctuations of single-particle diffusivity in a quenched environment'. Together they form a unique fingerprint.

    Cite this