Energy localization and shape transformations in semiflexible polymer rings

TL;DR

This paper investigates how energy input causes shape changes in semiflexible polymer rings, leading to shape transformations and energy localization due to internal excitations and external driving.

Contribution

It introduces a model linking internal excitations with shape transformations in driven polymer rings, revealing non-equilibrium phase transitions and energy localization phenomena.

Findings

Shape transitions from circular to elliptical or polygonal forms occur beyond a critical energy threshold.

Energy localizes in flatter regions of the chain during shape transformations.

External driving induces non-equilibrium phase transitions in the polymer rings.

Abstract

Shape transformations in driven and damped molecular chains are considered. Closed chains of weakly coupled molecular subunits under the action of spatially homogeneous time-periodic external field are studied. The coupling between the internal excitations and the bending degrees of freedom of the chain modifies the local bending rigidity of the chain. In the absence of driving the array takes a circular shape. When the energy pumped into the system exceeds some critical value the chain undergoes a non-equilibrium phase transition: the circular shape of the aggregate becomes unstable and the chain takes the shape of an ellipse or, in general, of a polygon. The excitation energy distribution becomes spatially nonuniform: it localizes in such places where the chain is more flat. The weak interaction of the chain with a flat surface restricts the dynamics to a flat manifold