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arXiv · 1712.02258

Critical behavior of active Brownian particles

Jonathan Tammo Siebert·Florian Dittrich·Friederike Schmid·Kurt Binder·Thomas Speck·Peter Virnau
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Abstract

We study active Brownian particles as a paradigm for genuine non-equilibrium phase transitions. Access to the critical point in computer simulations is obstructed by the fact that the density is conserved. We propose a modification of sampling finite-size fluctuations and successfully test this method for the 2D Ising model. Using this model allows us to determine accurately the critical point of two dimensional active Brownian particles at $\text{Pe}_{\text{cr}}=40(2)$, $ϕ_{\text{cr}}=0.597(3)$. Based on this estimate, we study the corresponding critical exponents $β$, $γ/ν$, and $ν$. Our results are incompatible with the 2D-Ising exponents, thus raising the question whether there exists a corresponding non-equilibrium universality class.

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Jonathan Tammo Siebert, Florian Dittrich, Friederike Schmid, Kurt Binder, Thomas Speck, Peter Virnau. 2017-12-06. Critical behavior of active Brownian particles. https://doi.org/10.1103/physreve.98.030601

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