Intriguing Heat Conduction of a Polymer Chain

TL;DR

This paper investigates heat conduction in a one-dimensional polymer chain with both longitudinal and transverse motions, revealing different divergence behaviors depending on coupling strength and temperature.

Contribution

It introduces a detailed molecular dynamics study of heat conduction in a 2D spring-connected chain with bending interactions, identifying new divergence regimes.

Findings

Logarithmic divergence with system size at high transverse coupling

1/3 power-law divergence at intermediate coupling

2/5 power-law divergence at low temperatures and weak coupling

Abstract

We study heat conduction in a one-dimensional chain of particles with longitudinal as well as transverse motions. The particles are connected by two-dimensional harmonic springs together with bending angle interactions. Using equilibrium and nonequilibrium molecular dynamics, three types of thermal conducting behaviors are found: a logarithmic divergence with system sizes for large transverse coupling, 1/3 power-law at intermediate coupling, and 2/5 power-law at low temperatures and weak coupling. The results are consistent with a simple mode-coupling analysis of the same model. The 1/3 power-law divergence should be a generic feature for models with transverse motions.