Limitations on the number of plasmons in nanoparticles

TL;DR

This paper investigates the thermal and mechanical limitations on plasmon excitation in nanoparticles, highlighting how heat generation, material properties, and electric forces constrain plasmon numbers for better engineering control.

Contribution

It introduces a model predicting a critical number of plasmons considering temperature-dependent losses, thermal conductivity, and heat boundary resistance in nanoparticles.

Findings

Existence of a critical plasmon number due to heat generation.

Kapitza resistance can dominate heat transfer limitations.

Electric forces impose additional strength constraints.

Abstract

In this letter, we address the thermal processes occurring in plasmonic nanoparticles. We determine constrains imposed upon the plasmonic excitation in such nanoparticle by the resulting heat generation. Taking into account temperature dependence of the metal losses, we predict the existence of the critical number of plasmons in the nanoparticle. We also allow for the temperature dependencies of the thermal-conductivity coefficient of the environment and the Kapitza heat boundary resistance. We show that the latter can dominate the overall heat resistance in the system. Strength limitations caused by the action of electric forces are also considered. Obtained results provide instruments for the heat and strength management in the plasmonic engineering.