Stretching semiflexible filaments with quenched disorder

TL;DR

This paper investigates how quenched disorder in spontaneous curvature affects the mechanical response of semiflexible filaments, providing analytical insights into force-elongation behavior and fluctuation widths, and contrasting quenched versus annealed disorder effects.

Contribution

It offers the first analytical analysis of quenched disorder effects on wormlike chains under tension, highlighting differences from annealed disorder and effects of transverse forces.

Findings

Quenched disorder alters force-elongation curves compared to pure systems.

Analytic expressions for transverse fluctuation widths are derived.

Quenched disorder effects cannot always be mimicked by changing stiffness.

Abstract

We study the effect of quenched randomness in the arc-length dependent spontaneous curvature of a wormlike chain under tension. In the weakly bending approximation in two dimensions, we obtain analytic results for the force-elongation curve and the width of transverse fluctuations. We compare quenched and annealed disorder and conclude that the former cannot always be reduced to a simple change in the stiffness of the pure system. We also discuss the effect of a random transverse force on the stretching response of a wormlike chain without spontaneous curvature.