title: Single-molecule optomechanics in "picocavities".
abstract: Trapping light with noble metal nanostructures overcomes the diffraction limit and can confine light to volumes typically on the order of 30 cubic nanometers. We found that individual atomic features inside the gap of a plasmonic nanoassembly can localize light to volumes well below 1 cubic nanometer ("picocavities"), enabling optical experiments on the atomic scale. These atomic features are dynamically formed and disassembled by laser irradiation. Although unstable at room temperature, picocavities can be stabilized at cryogenic temperatures, allowing single atomic cavities to be probed for many minutes. Unlike traditional optomechanical resonators, such extreme optical confinement yields a factor of 106enhancement of optomechanical coupling between the picocavity field and vibrations of individual molecular bonds. This work sets the basis for developing nanoscale nonlinear quantum optics on the single-molecule level.
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK.
authors.forename: Felix
authors.initials: F
authors.lastname: Benz
authors.affiliation: Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain.
authors.forename: Mikolaj K
authors.initials: MK
authors.lastname: Schmidt
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK.
authors.forename: Alexander
authors.initials: A
authors.lastname: Dreismann
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK.
authors.forename: Rohit
authors.initials: R
authors.lastname: Chikkaraddy
authors.affiliation: Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain.|Blackett Laboratory, London SW7 2AZ, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Demetriadou
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK.
authors.forename: Cloudy
authors.initials: C
authors.lastname: Carnegie
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK.
authors.forename: Hamid
authors.initials: H
authors.lastname: Ohadi
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK.
authors.forename: Bart
authors.initials: B
authors.lastname: de Nijs
authors.affiliation: Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain.
authors.forename: Ruben
authors.initials: R
authors.lastname: Esteban
authors.affiliation: Materials Physics Center CSIC-UPV/EHU and Donostia International Physics Center, 20018 Donostia-San Sebastián, Spain. jjb12@cam.ac.uk aizpurua@ehu.es.
authors.forename: Javier
authors.initials: J
authors.lastname: Aizpurua
authors.affiliation: NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK. jjb12@cam.ac.uk aizpurua@ehu.es.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Baumberg