Eur. Phys. J. E (2016) 39: 84
https://doi.org/10.1140/epje/i2016-16084-7

Regular Article

Applicability of effective pair potentials for active Brownian particles

Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128, Mainz, Germany

^* e-mail: thomas.speck@uni-mainz.de

Received: 30 March 2016
Accepted: 30 August 2016
Published online: 16 September 2016

Abstract

We have performed a case study investigating a recently proposed scheme to obtain an effective pair potential for active Brownian particles (Farage et al., Phys. Rev. E 91, 042310 (2015)). Applying this scheme to the Lennard-Jones potential, numerical simulations of active Brownian particles are compared to simulations of passive Brownian particles interacting by the effective pair potential. Analyzing the static pair correlations, our results indicate a limited range of activity parameters (speed and orientational correlation time) for which we obtain quantitative, or even qualitative, agreement. Moreover, we find a qualitatively different behavior for the virial pressure even for small propulsion speeds. Combining these findings we conclude that beyond linear response active particles exhibit genuine non-equilibrium properties that cannot be captured by effective pair interaction alone.