Share Email Print

Proceedings Paper

Molecular optomechanics in plasmonic cavities (Conference Presentation)
Author(s): Mikolaj Schmidt; Alejandro Gonzalez-Tudela; Geza Giedke; Tomas Neuman; Yao Zhang; Rubén Esteban; Javier Aizpurua

Paper Abstract

Surface-Enhanced Raman Scattering (SERS) is a fundamental spectroscopic technique that allows to access the rich vibrational structure of molecules. A typical SERS configuration with a molecule located in a plasmonic cavity acting as an optical nanoantenna enhances the vibrational (Stokes or anti-Stokes) signal of the molecule. A number of recent implementations of Raman experiments in plasmonic nanocavities appear to provide results which escape the standard description of the Raman process based on the classical treatment of the electromagnetic fields enhancement inside the cavity. We establish a novel analogy between non-resonant SERS in molecular spectroscopy and typical optomechanical processes. By adopting an optomechanical hamiltonian which describes the interaction between cavity plasmons and molecular vibrations, we are able to trace the quantum dynamics of both plasmons and vibrations in a SERS process. The solution of the master equation of this optomechanical hamiltonian allows to identify novel quantum effects such as the existence of different regimes of molecular vibrational build-up: a thermal vibrational regime, a vibrational pumping regime, and a strongly nonlinear vibrational regime, which emerge as a consequence of the quantum dynamics induced by the optomechanical interaction. Correlations between the Stokes and anti-Stokes Raman signals can also be traced for different temperatures and pumping powers. The presence of strong optomechanical effects in Raman has been recently addressed experimentally in special "picocavities" formed by a few metallic atoms in a plasmonic cavity. The strong optomechanical coupling achieved in this situation is found to activate the pumping regime in the Raman signal, thus corroborating the validity of this description.

Paper Details

Date Published: 21 September 2017
Proc. SPIE 10359, Quantum Nanophotonics, 103590J (21 September 2017); doi: 10.1117/12.2272962
Show Author Affiliations
Mikolaj Schmidt, Consejo Superior de Investigaciones Científicas (Spain)
Alejandro Gonzalez-Tudela, Max-Planck-Institut fur Quantenoptik (Germany)
Geza Giedke, Donostia International Physics Ctr. (Spain)
Ikerbasque (Spain)
Tomas Neuman, Consejo Superior de Investigaciones Científicas (Spain)
Donostia International Physics Ctr. (Spain)
Yao Zhang, Consejo Superior de Investigaciones Científicas (Spain)
Donostia International Physics Ctr. (Spain)
Rubén Esteban, Consejo Superior de Investigaciones Científicas (Spain)
Javier Aizpurua, Consejo Superior de Investigaciones Científicas (Spain)
Donostia International Physics Ctr. (Spain)

Published in SPIE Proceedings Vol. 10359:
Quantum Nanophotonics
Jennifer A. Dionne; Mark Lawrence, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?