Coarsening and Aging of Lattice Polymers: Influence of Bond Fluctuations

TL;DR

This study investigates the nonequilibrium collapse dynamics of lattice polymers, revealing how bond fluctuations influence cluster growth and aging, with universal scaling behaviors emerging when bonds fluctuate.

Contribution

It demonstrates that bond fluctuations lead to universal cluster growth and aging scaling laws, independent of temperature and bond type, in lattice polymer collapse.

Findings

Bond fluctuations produce temperature-independent cluster growth.

Aging autocorrelation follows a universal power-law scaling.

Cluster growth exhibits nonuniversal power-law behavior with fixed bonds.

Abstract

We present results for the nonequilibrium dynamics of collapse for a model flexible homopolymer on simple cubic lattices with fixed and fluctuating bonds between the monomers. Results from our Monte Carlo simulations show that, phenomenologically, the sequence of events observed during the collapse are independent of the bond criterion. While the growth of the clusters (of monomers) at different temperatures exhibits a nonuniversal power-law behavior when the bonds are fixed, the introduction of fluctuations in the bonds by considering the existence of diagonal bonds produces a temperature independent growth, which can be described by a universal nonequilibrium finite-size scaling function with a non-universal metric factor. We also examine the related aging phenomenon, probed by a suitable two-time density-density autocorrelation function showing a simple power-law scaling with respect to the growing cluster size. Unlike the cluster-growth exponent $\alpha_c $, the nonequilibrium autocorrelation exponent $\lambda_C$ governing the aging during the collapse, however, is independent of the bond type and strictly follows the bounds proposed by two of us in Phys. Rev. E 93, 032506 (2016) at all temperatures.