Heat Transport Through Plasmonic Interactions in Closely Spaced Metallic Nanoparticles Chains

TL;DR

This paper numerically investigates heat transfer in metallic nanoparticle chains, revealing how multipolar interactions and host material properties significantly influence thermal conductance and conductivity, with implications for nanofluids.

Contribution

It demonstrates the crucial role of multipolar interactions in plasmonic heat transfer and quantifies thermal conductance and conductivity in nanoparticle chains under different conditions.

Findings

Multipolar interactions greatly enhance ballistic thermal conductance when host dielectric constant is positive.

Negative dielectric constants lead to non-ballistic modes that suppress heat transfer.

Plasmonic thermal conductivity can reach 1% of bulk metal, explaining high thermal conductivity in nanofluids.

Abstract

We report a numerical investigation on the heat transfer through one dimensional arrays of metallic nanoparticles closely spaced in a host material. Our simulations show that the multipolar interactions play a crucial role in the heat transport via collective plasmons. Calculations of the plasmonic thermal conductance and of the thermal conductivity in ballistic and diffusive regime, respectively have been carried out. (a) Using the Landauer-Buttiker formalism we have found that, when the host material dielectric constant takes positive values, the multipolar interactions drastically enhance by several order of magnitude the ballistic thermal conductance of collective plasmons compared with that of a classical dipolar chain. On the contrary, when the host material dielectric constant takes negative values, we have demonstrated the existence of non-ballistic multipolar modes which annihilate the heat transfer through the chains. (b) Using the kinetic theory we have also examined the thermal behavior of chains in the diffusion approximation. We have shown that the plasmonic thermal conductivity of metallic nanoparticle chains can reach 1% of the bulk metal thermal conductivity . This result could explain the anomalously high thermal conductivity observed in many collo\"idal suspensions, the so called nanofluids.