Tagged Particle in Single-File Diffusion

P. L. Krapivsky (1) , Kirone Mallick (2) , Tridib Sadhu (2)

1 BU - Boston University [Boston]
2 IPHT - Institut de Physique Théorique - UMR CNRS 3681

Single-file diffusion is a one-dimensional interacting infinite-particle system in which the order of particles never changes. An intriguing feature of single-file diffusion is that the mean-square displacement of a tagged particle exhibits an anomalously slow sub-diffusive growth. We study the full statistics of the displacement using a macroscopic fluctuation theory. For the simplest single-file system of impenetrable Brownian particles we compute the large deviation function and provide an independent verification using an exact solution based on the microscopic dynamics. For an arbitrary single-file system, we apply perturbation techniques and derive an explicit formula for the variance in terms of the transport coefficients. The same method also allows us to compute the fourth cumulant of the tagged particle displacement for the symmetric exclusion process.

Keywords: Anomalous diffusion; Macroscopic fluctuation theory; Single-file diffusion; Large deviations

Domains: Physics [physics]

P. L. Krapivsky, Kirone Mallick, Tridib Sadhu. Tagged Particle in Single-File Diffusion. Journal of Statistical Physics, 2015, 160 (4), pp.885-925. ⟨10.1007/s10955-015-1291-0⟩. ⟨cea-01304701⟩