Focusing by blocking: Repeatedly generating central density peaks in self-propelled particle systems by exploiting diffusive processes

Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf D-40225 Düsseldorf, Germany

Received: 7 February 2015
Accepted: 7 May 2015

Abstract

Over the past few years the displacement statistics of self-propelled particles has been intensely studied, revealing their long-time diffusive behavior. Here, we demonstrate that a concerted combination of boundary conditions and switching on and off the self-propelling drive can generate and afterwards arbitrarily often restore a non-stationary centered peak in their spatial distribution. This corresponds to a partial reversibility of their statistical behavior, in opposition to the above-mentioned long-time diffusive nature. Interestingly, it is a diffusive process that mediates and makes possible this procedure. It should be straightforward to verify our predictions in a real experimental system.