Thermal conductivity of the chain with an asymmetric pair interaction

TL;DR

This study uses molecular dynamics to analyze heat transport in one-dimensional chains, showing that chains with bond-dissociating potentials have finite thermal conductivity, unlike those with confining potentials which exhibit divergence.

Contribution

It demonstrates that bond-dissociating potentials lead to finite thermal conductivity in 1D chains, contrasting with confining potentials that cause divergence, advancing understanding of heat transport mechanisms.

Findings

Chains with Lennard-Jones, Morse, Coulomb potentials have finite conductivity.

Convergence due to phonon scattering on loose bonds at low T.

Confining potentials lead to diverging thermal conductivity.

Abstract

We provide molecular dynamics simulation of heat transport in one-dimensional molecular chains with different interparticle pair potentials. We show that the thermal conductivity is finite in the thermodynamic limit in the chains with the potential, which allows for bond dissociation. The Lennard-Jones, Morse and Coulomb potentials belong to such type of potentials. The convergence of the thermal conductivity is provided by phonon scattering on the locally stretched loose interatomic bonds at low temperature and by the many-particle scattering at high temperature. On the other hand, the chains with the confining pair potential, which does not allow for the bond dissociation, posses anomalous (diverging with the chain length) thermal conductivity. We emphasize that the chains with the symmetric or asymmetric Fermi-Pasta-Ulam potential or with the combined potentials containing parabolic confining potential all exhibit anomalous heat transport.