Enhanced diffusivity in microscopically reversible active matter

Abstract

Physics of self-propelled objects at the nanoscale is a rapidly developing research field where recent experiments focused on motion of individual catalytic enzymes. Contrary to the experimental advancements, theoretical understanding of possible self-propulsion mechanisms at these scales is limited. A particularly puzzling question concerns origins of reportedly high diffusivities of the individual enzymes. Here we start with the fundamental principle of microscopic reversibility (MR) of chemical reactions powering the self-propulsion and demonstrate that MR can lead to increase of the particle mobility and of short- and long-time diffusion coefficients as compared to dynamics where MR is neglected. Moreover, the diffusion coefficients can be enhanced by a constant external force. We propose a way to use these effects in experimental investigations of active propulsion mechanisms at the nanoscale. Our results can shed new light on interpretation of the measured diffusivities and help to test and to evaluate relevance of MR for the active motion of individual nanoswimmers.