Heating of a semi-infinite Hooke chain

TL;DR

This paper provides an analytical study of unsteady ballistic heat transport in a semi-infinite Hooke chain, revealing how heat pulses influence thermal wave behavior and steady states at the nanoscale.

Contribution

It offers a novel analytical description of kinetic temperature evolution in discrete and continuum models for a semi-infinite Hooke chain with arbitrary heat sources.

Findings

Instantaneous heat supply causes anti-localization of reflected thermal waves.

Sudden point heat supply can lead to a non-equilibrium steady state.

Continuum approximation captures key features of nanoscale heat transport.

Abstract

We consider unsteady ballistic heat transport in a semi-infinite Hooke chain with a free end and an arbitrary heat source. An analytical description of the evolution of the kinetic temperature is proposed in both discrete (exact) and continuum (approximate) formulations. The continualization of the discrete solution for kinetic temperature is performed through a large-time asymptotic estimate of the fundamental solution of the dynamical problem for the instantly perturbed conservative semi-infinite chain at the fronts of the incident and reflected thermal waves. By analyzing the continuum solution, we observe that any instantaneous heat supply (i.e., a heat pulse) results in the anti-localization of the reflected thermal wave. We demonstrate that sudden point heat supply leads to a transition to a non-equilibrium steady state, which, unexpectedly, may exist even in the non-dissipative case. The results of this paper are expected to provide insight into the continuum description of nanoscale heat transport.