Effective forces between active polymers

TL;DR

This study investigates how active fluctuations influence the interactions between flexible polymers, revealing conditions where activity induces strong attractions and conformational changes, including polymer merging.

Contribution

It introduces models of active fluctuations into polymer interactions and maps conditions where active effects mimic passive interactions or lead to new behaviors.

Findings

Active baths induce strong attractive interactions.

Polymers can merge into double-stranded units under activity.

A phase diagram characterizes conformational transitions.

Abstract

The characterization of the interactions between two fully flexible self-avoiding polymers is one of the classic and most important problems in polymer physics. In this paper we measure these interactions in the presence of active fluctuations. We introduce activity into the problem using two of the most popular models in this field. One where activity is effectively embedded into the monomers' dynamics, and the other where passive polymers fluctuate in an explicit bath of active particles. We establish the conditions under which the interaction between active polymers can be mapped into the classical passive problem. We observe that the active bath can drive the development of strong attractive interactions between the polymers and that, upon enforcing a significant degree of overlap, they come together to form a single double-stranded unit. A phase diagram tracing this change in conformational behavior is also reported.