Franco Bonafé
(Max Planck Institute for the Structure and Dynamics of Matter, Germany)

Abstract:
 
Plasmonic near-field dynamics and its interaction with molecules have been an exciting area of research for years. Numerical simulations can give access to the electrodynamics at the atomic scale; however, given the dimensions of typical nanoplasmonic junctions (e.g. in scanning tunneling microscopes, STM), only classical electromagnetic models are normally used, ignoring the quantum effects on electronic and nuclear properties of adsorbed molecules (e.g. adsorption geometry) as well as of the metallic contacts. Hence, a full quantum dynamical description is sometimes inescapable.
In this seminar I will present insights on ab-initio, light-driven, real-time dynamics at the atomistic level in STM cavities, which highlight the role of the electron dynamics (e.g. tunneling) and structural relaxation to properly reproduce experimental features of the local fields. Among other results, the quantitative sampling of atomic-scale waveforms by means of a single-molecule switch, as well as the tip-enhanced Raman scattering of single-atom vibrations in a picocavity, will be discussed. The simulations were done within the time-dependent density functional theory using the Octopus code. Finally, I will also present some outlooks on improving the microscopic description of atomic-scale light-matter interactions in nanoplasmonic cavities by a full ab-initio treatment of electrons, nuclei and photons via a density-functional reformulation of non-relativistic quantum electrodynamics, which leads to coupled Ehrenfest-Maxwell-Pauli-Kohn-Sham equations, also implemented in the Octopus code.

 

Zoom link for advance registration:

https://zoom.us/meeting/register/tJYrdOiuqjsrH9RiaIZpscGiqinhCIxVKYZ9