Diffusion of active particles driven by odd interactions.

Abstract

Odd systems do not conserve energy, violate time-reversal symmetry, and remain far from equilibrium. How odd interactions between particles affect their diffusion remains unknown. To investigate this issue, we studied the diffusion and glass transition of a two-dimensional Kob-Andersen mixture, where Brownian particles interact via the Lennard-Jones potential and nonconservative odd forces. Our findings indicate a significant influence of odd interactions on the system's diffusion dynamics. Odd interactions always promote diffusion. These interactions lead to a nonmonotonic relationship between the effective diffusion coefficient and particle number density. Specifically, in systems with low oddness, the diffusion coefficient decreases steadily with increasing particle number density. Conversely, in systems with moderate oddness, an optimal particle number density exists that maximizes the diffusion coefficient. For systems with high oddness, we observe two distinct peaks in the diffusion coefficient-particle number density relationship. Furthermore, our investigation into the glass transition under dense conditions reveals that adjusting the oddness at low temperatures can induce a transition from a glassy state to a liquid state. Our findings offer a deeper insight into the diffusion processes in systems with odd interactions from a critical perspective.