Plasmon - exciton interactions at a single nanoantenna level
DIPC Seminars
- Speaker
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Timur Shegai, Department of Physics, Chalmers University of Technology, Göteborg
- When
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2018/12/10
13:00 - Place
- Donostia International Physics Center
- Add to calendar
-
iCal
Strong light-matter interactions in microcavities have been long known to
provide means to alter optical and nonlinear properties of the coupled system.
As a result of this interaction, one typically observes the emergence of new
polaritonic eigenstates of the coupled system. These states are of hybrid
nature and possess both light and matter characteristics, which is reflected
as so-called vacuum Rabi splitting, observed in the absorption or transmission
spectra. Because of the hybrid nature of these states, the excited state
temporal dynamics can be significantly altered in comparison to the uncoupled
system dynamics. This, in turn, can have profound effects on the emission and
photochemical processes.
In this talk I will discuss our recent results on individual plasmonic
nanoantennas strongly coupled to molecular J-aggregates 1-4 and 2D materials
5. In the case of J-aggregates we observe Rabi splitting up to 400 meV, i.e.
~20% of the resonance energy. Moreover, we observe mode splitting not only in
elastic scattering but also in photoluminescence of individual hybrid
nanosystems, which manifests a direct proof of strong coupling in plasmon-
exciton nanoparticles. This situation is drastically different from the
photoluminescence of uncoupled molecules, which signals the involvement of
polaritonic states into the relaxation pathways of the hybrid system. I also
discuss how the involvement of these pathways can modify other relevant
excited state dynamics, including photo-oxidation processes 4. In the case of
2D materials, we observe complex temperate-dependent plasmon-exciton polariton
mixtures, which at low temperatures can admix trions (charged excitons) into a
common polaritonic state 5. Such admixture can be interesting in the context
of polariton-polariton interactions and potentially for the charge transport
in strongly coupled systems.
References
1\. Zengin, G.; Johansson, G.; Johansson, P.; Antosiewicz, T. J.; Käll, M.;
Shegai, T. Sci. Rep. 2013, 3, 3074.
2\. Zengin, G.; Wersäll, M.; Nilsson, S.; Antosiewicz, T. J.; Käll, M.;
Shegai, T. Physical Review Letters 2015, 114, (15), 157401.
3\. Wersäll, M.; Cuadra, J.; Antosiewicz, T. J.; Balci, S.; Shegai, T. Nano
Letters 2017, 17, (1), 551-558.
4\. Munkhbat, B.; Wersäll, M.; Baranov, D. G.; Antosiewicz, T. J.; Shegai, T.
arXiv preprint 2018, arXiv:1802.06616.
5\. Cuadra, J.; Baranov, D. G.; Wersäll, M.; Verre, R.; Antosiewicz, T. J.;
Shegai, T. Nano Letters 2018.
Host: Yury Rakovich