Coherent Acoustic Phonons in Plasmonic Nanoparticles: Elastic Properties and Dissipation at Low Temperatures

Hilario D. Boggiano, Thomas Possmayer, Luis Morguet, Lin Nan, Luca Sortino, Stefan A. Maier, Emiliano Cortés, Gustavo Grinblat, Andrea V. Bragas, Leonardo de S. Menezes

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We studied the frequency and quality factor of mechanical plasmonic nanoresonators as a function of temperature, ranging from ambient to 4 K. Our investigation focused on individual gold nanorods and nanodisks of various sizes. We observed that oscillation frequencies increase linearly as temperature decreases until saturation is reached at cryogenic temperatures. This behavior is explained by the temperature dependence of the elastic modulus, with a Debye temperature compatible with reported bulk values for gold. To describe the behavior of the quality factor, we developed a model considering the nanostructures as anelastic solids, identifying a dissipation peak around 150 K due to a thermally activated process, likely of the Niblett-Wilks mechanism type. Importantly, our findings suggest that external dissipation factors are more critical to improving quality factors than internal friction, which can be increased by modifying the nanoresonator’s environment. Our results enable the future design of structures with high vibration frequencies and quality factors by effectively controlling external losses.

Original languageEnglish
Pages (from-to)31903-31911
Number of pages9
JournalACS Nano
Volume18
Issue number46
DOIs
Publication statusPublished - 7 Nov 2024

Keywords

  • coherent acoustic phonons
  • dissipation mechanisms
  • elastic modulus
  • low temperature
  • plasmonic nanoantennas

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