Anomalously Large Spectral Shifts near the Quantum Tunnelling Limit in Plasmonic Rulers with Subatomic Resolution.
de Nijs, Bart
American Chemical Society
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Readman, C., de Nijs, B., Szabó, I., Demetriadou, A., Greenhalgh, R., Durkan, C., Rosta, E., et al. (2019). Anomalously Large Spectral Shifts near the Quantum Tunnelling Limit in Plasmonic Rulers with Subatomic Resolution.. Nano letters, 19 (3), 2051-2058. https://doi.org/10.1021/acs.nanolett.9b00199
The resonance wavelength of a coupled plasmonic system is extremely sensitive to the distance between its metallic surfaces, resulting in 'plasmon rulers'. We explore this behaviour in the sub-nm regime using self-assembled monolayers of bis-phthalocyanine molecules in a nanoparticle-on-mirror (NPoM) construct. These allow unprecedented sub-angstrom control over spacer thickness via choice of metal centre, in a gap-size regime at the quantum-mechanical limit of plasmonic enhancement. A dramatic shift in the coupled plasmon resonance is observed as the gap size is varied from 0.39 to 0.41 nm. Existing theoretical models are unable to account for the observed spectral tuning, which requires inclusion of the quantum-classical interface, emphasising the need for new treatments of light at the sub-nanoscale.
EC FP7 MC ITN (235114)
Isaac Newton Trust (18.08(K))
Leverhulme Trust (ECF-2018-021)
External DOI: https://doi.org/10.1021/acs.nanolett.9b00199
This record's URL: https://www.repository.cam.ac.uk/handle/1810/289533