Vibronic Raman Scattering at the Quantum Limit of Plasmons

Journal Article · Wed Jul 09 04:00:00 EDT 2014 · Nano Letters, 14(7):4114-4118

DOI:https://doi.org/10.1021/nl501690u· OSTI ID:1171286

El-Khoury, Patrick Z.; Hess, Wayne P.

We record sequences of Raman spectra at a plasmonic junction formed by a gold AFM tip in contact with a silver surface coated with 4,4’-dimercaptostilbene (DMS). A 2D correlation analysis of the recorded trajectories reveals that the observable vibrational states can be divided into sub-sets. The first set comprises the totally symmetric vibrations of DMS (ag) that are neither correlated with each other nor to the fluctuating background, which is assigned to the signature of charge transfer plasmons tunneling through DMS. The second set consists of bu vibrations, which are correlated both with each other and with the continuum. Our findings are rationalized on the basis of the charge-transfer theory of Raman scattering, and illustrate how the tunneling plasmons modulate the vibronic coupling term from which the intensities of the bu states are derived.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1171286
• Report Number(s): PNNL-SA-102123; 48129; KC0301020
• Journal Information: Nano Letters, 14(7):4114-4118, Journal Name: Nano Letters, 14(7):4114-4118
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory