Evidence of Rouse-like dynamics in magnetically ratchetting colloidal chains

Abstract

We study the collective dynamics of an ensemble of paramagnetic particles organized as a 1D chain and driven by an a-thermal ratchet effect on a uniaxial garnet film. The centre of mass of the chain shows diffusive behavior with mean square displacement ∼t, while its end-to-end distance shows anomalous (sub-diffusive) kinetics growing as . We extract the potential of mean force between the particles within the chain by invoking the Pope–Ching equation. We interpret the experimental data using the Rouse model, originally developed for polymers, and experimentally extract all relevant parameters.