King's College London

Research portal

Single-molecule strong coupling at room temperature in plasmonic nanocavities

Research output: Contribution to journalArticlepeer-review

Rohit Chikkaraddy, Bart De Nijs, Felix Benz, Steven J. Barrow, Oren A. Scherman, Edina Rosta, Angela Demetriadou, Peter Fox, Ortwin Hess, Jeremy J. Baumberg

Original languageEnglish
Article number17974
Number of pages4
Early online date13 Jun 2016
Accepted/In press1 Apr 2016
E-pub ahead of print13 Jun 2016
Published7 Jul 2016


King's Authors


Photon emitters placed in an optical cavity experience an environment that changes how they are coupled to the surrounding light field. In the weak-coupling regime, the extraction of light from the emitter is enhanced. But more profound effects emerge when single-emitter strong coupling occurs: mixed states are produced that are part light, part matter1, 2, forming building blocks for quantum information systems and for ultralow-power switches and lasers3, 4, 5, 6. Such cavity quantum electrodynamics has until now been the preserve of low temperatures and complicated fabrication methods, compromising its use5, 7, 8. Here, by scaling the cavity volume to less than 40 cubic nanometres and using host–guest chemistry to align one to ten protectively isolated methylene-blue molecules, we reach the strong-coupling regime at room temperature and in ambient conditions. Dispersion curves from more than 50 such plasmonic nanocavities display characteristic light–matter mixing, with Rabi frequencies of 300 millielectronvolts for ten methylene-blue molecules, decreasing to 90 millielectronvolts for single molecules—matching quantitative models. Statistical analysis of vibrational spectroscopy time series and dark-field scattering spectra provides evidence of single-molecule strong coupling. This dressing of molecules with light can modify photochemistry, opening up the exploration of complex natural processes such as photosynthesis9 and the possibility of manipulating chemical bonds10.

Download statistics

No data available

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454