Heat transfer between nanoparticles: Thermal conductance for near-field interactions

TL;DR

This paper investigates near-field heat transfer between two charged nanoparticles, deriving a theoretical model based on fluctuating multipole moments and comparing it with molecular dynamics simulations to explain conductance behavior.

Contribution

It introduces a formalism for calculating thermal conductance via Coulomb interactions using fluctuation-dissipation theorem, enhancing understanding of near-field heat transfer.

Findings

Conductance increases sharply as nanoparticles approach each other.

Theoretical results agree with molecular dynamics simulations.

Formalism explains the growth of conductance at short distances.

Abstract

We analyze the heat transfer between two nanoparticles separated by a distance lying in the near-field domain in which energy interchange is due to Coulomb interactions. The thermal conductance is computed by assuming that the particles have charge distributions characterized by fluctuating multipole moments in equilibrium with heat baths at two different temperatures. This quantity follows from the fluctuation-dissipation theorem (FDT) for the fluctuations of the multipolar moments. We compare the behavior of the conductance as a function of the distance between the particles with the result obtained by means of molecular dynamics simulations. The formalism proposed enables us to provide a comprehensive explanation of the marked growth of the conductance when decreasing the distance between the nanoparticles.