Kunimasa Miyazaki (Nagoya University):Chirality and Hyperuniformity of Active Matter

Conventional wisdom tells us that the chirality of the constituent molecules does not change the thermodynamic properties. Conventional wisdom also tells us that the fluctuations of the system increase near a critical point of the phase transition. But these are only true for systems in thermal equilibrium. In this talk I will show that these conventional wisdoms do not hold in active matter (a class of systems or model systems that mimic a herd or flock of animals). We use a very simple spherical “animal” model, called Active Brownian Particles and numerically study their “thermodynamic” properties. By tuning the chirality, the self-propulsion forces, and the “capriciousness” (or fluctuations) of a particle, it is found that the macroscopic properties change drastically and system’s fluctuations are suppressed. These results undermine some of the most fundamental principles of thermodynamics.