Plasmon-driven motion of an individual molecule

TL;DR

This paper shows that nanocavity plasmons can remotely induce motion in individual molecules, revealing a new way to control molecular dynamics using nanoplasmonic effects.

Contribution

It demonstrates plasmon-driven molecular motion through combined STM and spectroscopy techniques, highlighting a novel remote control mechanism.

Findings

Nanocavity plasmons induce molecular shuttling motion.

Luminescence spectra reveal plasmon-exciton coupling effects.

Remote plasmonic control enables directed molecular motion.

Abstract

We demonstrate that nanocavity plasmons generated a few nanometers away from a molecule can induce molecular motion. For this, we study the well-known rapid shuttling motion of zinc phthalocyanine molecules adsorbed on ultrathin NaCl films by combining scanning tunneling microscopy (STM) and spectroscopy (STS) with STM-induced light emission. Comparing spatially resolved single-molecule luminescence spectra from molecules anchored to a step edge with isolated molecules adsorbed on the free surface, we found that the azimuthal modulation of the Lamb shift is diminished in case of the latter. This is evidence that the rapid shuttling motion is remotely induced by plasmon-exciton coupling. Plasmon-induced molecular motion may open an interesting playground to bridge the nanoscopic and mesoscopic worlds by combining molecular machines with nanoplasmonics to control directed motion of single molecules without the need for local probes.