Strong vibrational coupling in room temperature plasmonic resonators
Abstract
Strong vibrational coupling has been realized in a variety of mechanical systems. However, there have been no experimental observations of strong coupling of the acoustic modes of plasmonic nanostructures, due to rapid energy dissipation in these systems. Here we realized strong vibrational coupling in ultra-high frequency plasmonic nanoresonators by increasing the vibrational quality factors by an order of magnitude. We achieved the highest frequency quality factor products of f × Q = 1.0 × 10¹³ Hz for the fundamental mechanical modes, which exceeds the value of 0.6 × 10¹³ Hz required for ground state cooling. Avoided crossing was observed between vibrational modes of two plasmonic nanoresonators with a coupling rate of g = 7.5 ± 1.2 GHz, an order of magnitude larger than the dissipation rates. The intermodal strong coupling was consistent with theoretical calculations using a coupled oscillator model. Our results enabled a platform for future observation and control of the quantum behavior of phonon modes in metallic nanoparticles.
Copyright and License
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Acknowledgement
This work was supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 61705133, 11734012, 11574218, 51502280), the Science and Technology Innovation Commission of Shenzhen (Grant No. JCYJ20170818143739628), and Natural Science Foundation of SZU (Grant No. 827/000267). G.V.H. acknowledges the support of the US National Science Foundation through award CHE-1502848. J.E.S. acknowledges support from the Australian Research Council Centre of Excellence in Exciton Science (CE170100026) and the Australian Research Council Grants Scheme.
Data Availability
The source data underlying Fig. 1b, c, e, f, 2a, b, 3a, b and 4a, b, are provided as a Source Data file. Supplementary Figures and other images of this study are available from the corresponding authors upon reasonable request.
Conflict of Interest
The authors declare no competing interests.
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Additional details
- PMCID
- PMC6449381
- 61705133
- National Natural Science Foundation of China
- 11734012
- National Natural Science Foundation of China
- 11574218
- National Natural Science Foundation of China
- 51502280
- National Natural Science Foundation of China
- CHE-1502848
- National Science Foundation
- CE170100026
- Australian Research Council