Coherent acoustic vibration of metal nanoshells

TL;DR

This study uses time-resolved spectroscopy to explore the vibrational modes of gold nanoshells, revealing their unique acoustic signatures and offering new ways to identify and analyze these nanostructures.

Contribution

First experimental investigation of gold nanoshell vibrational modes using pump-probe spectroscopy, confirming theoretical predictions and highlighting their distinct acoustical properties.

Findings

Nanoshells exhibit a stronger modulation amplitude than nanoparticles of similar size.

The vibrational period of nanoshells is longer than that of comparable nanoparticles.

The acoustical signature can be used to identify and study nanoshells' properties.

Abstract

Using time-resolved pump-probe spectroscopy we have performed the first investigation of the vibrational modes of gold nanoshells. The fundamental isotropic mode launched by a femtosecond pump pulse manifests itself in a pronounced time-domain modulation of the differential transmission probed at the frequency of nanoshell surface plasmon resonance. The modulation amplitude is significantly stronger and the period is longer than in a gold nanoparticle of the same overall size, in agreement with theoretical calculations. This distinct acoustical signature of nanoshells provides a new and efficient method for identifying these versatile nanostructures and for studying their mechanical and structural properties.