Year: 2019
Type: article
Abstract: We show that observing the trajectories of confined particles in a thermal equilibrium state yields an estimate on the free-space diffusion coefficient. For generic trapping potentials and interactions between particles, the estimate comes in the form of a lower bound on the true diffusion coefficient. For non-interacting particles in harmonic trapping potentials, which approximately describes many experimental situations, the estimate is asymptotically exact. This allows to determine the diffusion coefficient from an equilibrium measurement, as opposed to a direct observation of diffusion, which necessarily starts from a non-equilibrium state. We explicitly demonstrate that the estimate remains quantitatively accurate in the presence of weak interactions and anharmonic corrections.
Source: Europhysics Letters (EPL)
Author: Andreas Dechant
Language: English
Subfield: Statistical and Nonlinear Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G4747886261
OpenAlex ID: W2811069762