Dynamics of Active Polar Ring Polymers

TL;DR

This paper analytically investigates the conformational and dynamical behaviors of active polar ring polymers, revealing activity-induced changes in internal dynamics and distinct motion regimes, including enhanced diffusion and snake-like motion.

Contribution

It provides an analytical solution showing that activity influences internal ring dynamics and identifies new characteristic motion regimes in active polar ring polymers.

Findings

Ring conformations are independent of activity.

Activity induces a diffusive regime in flexible rings.

Semiflexible rings exhibit ballistic motion and snake-like dynamics.

Abstract

The conformational and dynamical properties of isolated semiflexible active polar ring polymers are investigated analytically. A ring is modeled as continuous Gaussian polymer exposed to tangential active forces. The analytical solution of the linear non-Hermitian equation of motion in terms of an eigenfunction expansion shows that ring conformations are independent of activity. In contrast, activity strongly affects the internal ring dynamics and yields characteristic time regimes, which are absent in passive rings. On intermediate time scales, flexible rings show an activity-enhanced diffusive regime, while semiflexible rings exhibit ballistic motion. Moreover, a second active time regime emerges on longer time scales, where rings display a snake-like motion, which is reminiscent to a tank-treading rotational dynamics in shear flow, dominated by the mode with the longest relaxation time.