- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Letters

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Editors' Suggestion
  • Open Access

Coherent Dynamics of Molecular Vibrations in Single Plasmonic Nanogaps

Fiona Bell, Lukas Jakob, Caleb Todd, Ishaan Lohia, Yeeun Roh, Rakesh Arul*, and Jeremy J. Baumberg†

  • NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, JJ Thompson Avenue, University of Cambridge, Cambridge CB3 0US, United Kingdom

  • *Contact author: ra554@cam.ac.uk
  • †Contact author: jjb12@cam.ac.uk
PDF

Phys. Rev. Lett. 135, 076901 – Published 15 August, 2025

DOI: https://doi.org/10.1103/txdw-nqvn

Abstract

Coupling with a resonant optical cavity is well known to modify the coherence of molecular vibrations. However, in the case of molecules coupled to a plasmonic nanocavity mode, the local mechanisms of vibrational coherence decay remain unclear. Here, the dynamics of a few hundred molecules of nitrothiophenol (NTP) within a single plasmonic nanocavity are studied by sum-frequency generation. Time-resolved experiments reveal a coherence lifetime sensitive to intermolecular dipole coupling strength, and is found to compete with cavity-induced vibrational dephasing above a threshold ∼10  cm−1. Tuning of the system dipole strength presents a quantitative means to explore the energy landscape of coherent interactions within nanoscale vibrational platforms, relevant for studies from vibrational chemistry to cavity quantum optomechanics.

View figure in article

Physics Subject Headings (PhySH)

Article Text

Supplemental Material

References (52)

  1. S. R. Rather, G. D. Scholes, and L. X. Chen, From coherence to function: Exploring the connection in chemical systems, Acc. Chem. Res. 57, 2620 (2024).
  2. P. Ghosh et al., Decoupling excitons from high-frequency vibrations in organic molecules, Nature (London) 629, 355 (2024).
  3. J. J. Baumberg, J. Aizpurua, M. H. Mikkelsen, and D. R. Smith, Extreme nanophotonics from ultrathin metallic gaps, Nat. Mater. 18, 668 (2019).
  4. C. Carnegie et al., Room-temperature optical picocavities below 1 nm 3 accessing single-atom geometries, J. Phys. Chem. Lett. 9, 7146 (2018).
  5. Z. Zhang, C. Zhang, H. Zheng, and H. Xu, Plasmon-driven catalysis on molecules and nanomaterials, Acc. Chem. Res. 52, 2506 (2019).
  6. V. Pouthier, Vibrational exciton mediated quantum state transfer: Simple model, Phys. Rev. B 85, 214303 (2012).
  7. S. T. Velez, K. Seibold, N. Kipfer, M. D. Anderson, V. Sudhir, and C. Galland, Preparation and decay of a single quantum of vibration at ambient conditions, Phys. Rev. X 9, 041007 (2019).
  8. A. Xomalis, X. Zheng, R. Chikkaraddy, Z. Koczor-Benda, E. Miele, E. Rosta, G. A. E. Vandenbosch, A. Martínez, and J. J. Baumberg, Detecting mid-infrared light by molecular frequency upconversion in dual-wavelength nanoantennas, Science 374, 1268 (2021).
  9. W. Chen et al., Continuous-wave frequency upconversion with a molecular optomechanical nanocavity, Science 374, 1264 (2021).
  10. A. L. Harris, L. Rothberg, L. Dhar, N. J. Levinos, and L. H. Dubois, Vibrational energy relaxation of a polyatomic adsorbate on a metal surface: Methyl thiolate (CH3S) on Ag(111), J. Chem. Phys. 94, 2438 (1991).
  11. C. Matranga and P. Guyot-Sionnest, Vibrational relaxation of cyanide at the metal/electrolyte interface, J. Chem. Phys. 112, 7615 (2000).
  12. W. G. Roeterdink, O. Berg, and M. Bonn, Frequency- and time-domain femtosecond vibrational sum frequency generation from CO adsorbed on Pt(111), J. Chem. Phys. 121, 10174 (2004).
  13. H. S. AlSalem and S. P. K. Koehler, Ultrafast vibrational dephasing times of modified graphene, J. Phys. Chem. C 126, 7571 (2022).
  14. L. A. Jakob, W. M. Deacon, R. Arul, B. De Nijs, N. S. Mueller, and J. J. Baumberg, Accelerated molecular vibrational decay and suppressed electronic nonlinearities in plasmonic cavities through coherent Raman scattering, Phys. Rev. B 109, 195404 (2024).
  15. X. Zheng, Q. Pei, J. Tan, S. Bai, Y. Luo, and S. Ye, Local electric field in nanocavities dictates the vibrational relaxation dynamics of interfacial molecules, Chem. Sci. 15, 11507 (2024).
  16. R. Wilcken, J. Nishida, J. F. Triana, A. John-Herpin, H. Altug, S. Sharma, F. Herrera, and M. B. Raschke, Antenna-coupled infrared nanospectroscopy of intramolecular vibrational interaction, Proc. Natl. Acad. Sci. U.S.A. 120, e2220852120 (2023).
  17. W. G. Roeterdink, O. Berg, and M. Bonn, Frequency- and time-domain femtosecond vibrational sum frequency generation from CO adsorbed on Pt(111), J. Chem. Phys. 121, 10174 (2004).
  18. B. N. J. Persson and R. Ryberg, Vibrational interaction between molecules adsorbed on a metal surface: The dipole-dipole interaction, Phys. Rev. B 24, 6954 (1981).
  19. A. V. Snigur and V. M. Rozenbaum, Davydov splitting of vibrational spectra of adsorbates, Opt. Spectrosc. 95, 685 (2003).
  20. J. A. Lau, A. M. Schönemann, D. Schwarzer, A. M. Wodtke, J. A. Lau, and A. M. Wodtke, The coverage dependence of the infrared absorption of CO adsorbed to NaCl(100), J. Chem. Phys. 153 (2020).
  21. J. Heidberg, E. Kampshoff, and M. Suhren, Correlation field, structure, and phase transition in the monolayer CO adsorbed on NaCl(100) as revealed from polarization Fourier-transform infrared spectroscopy, J. Chem. Phys. 95, 9408 (1991).
  22. F. M. Hoffmann, Infrared reflection-absorption spectroscopy of adsorbed molecules, Surf. Sci. Rep. 3, 107 (1983).
  23. Y. Zhang, J. Aizpurua, and R. Esteban, Optomechanical collective effects in surface-enhanced Raman scattering from many molecules, ACS Photonics 7, 1676 (2020).
  24. P. Roelli, C. Galland, N. Piro, and T. J. Kippenberg, Molecular cavity optomechanics as a theory of plasmon-enhanced Raman scattering, Nat. Nanotechnol. 11, 164 (2016).
  25. R. Esteban, J. J. Baumberg, and J. Aizpurua, Molecular optomechanics approach to surface-enhanced Raman scattering, Acc. Chem. Res. 55, 1889 (2022).
  26. P. Roelli, H. Hu, E. Verhagen, S. Reich, and C. Galland, Nanocavities for molecular optomechanics: Their fundamental description and applications, ACS Photonics 11 (2024).
  27. A. Lombardi, M. K. Schmidt, L. Weller, W. M. Deacon, F. Benz, B. De Nijs, J. Aizpurua, and J. J. Baumberg, Pulsed molecular optomechanics in plasmonic nanocavities: From nonlinear vibrationalinstabilities to bond-breaking, Phys. Rev. X 8, 1 (2018).
  28. L. A. Jakob et al., Giant optomechanical spring effect in plasmonic nano- and picocavities probed by surface-enhanced Raman scattering, Nat. Commun. 14, 1 (2023).
  29. M. Linke, M. Hille, M. Lackner, L. Schumacher, S. Schlücker, and E. Hasselbrink, Plasmonic effects of Au nanoparticles on the vibrational sum frequency spectrum of 4-nitrothiophenol, J. Phys. Chem. C 123, 24234 (2019).
  30. F. Cecchet, D. Lis, J. Guthmuller, B. Champagne, G. Fonder, Z. Mekhalif, Y. Caudano, A. A. Mani, P. A. Thiry, and A. Peremans, Theoretical calculations and experimental measurements of the vibrational response of p-NTP SAMs: An orientational analysis, J. Phys. Chem. C 114, 4106 (2010).
  31. T. P. Gray, J. Nishida, S. C. Johnson, and M. B. Raschke, 2D vibrational exciton nanoimaging of domain formation in self-assembled monolayers, Nano Lett. 21, 5754 (2021).
  32. N. S. Mueller, R. Arul, L. A. Jakob, M. O. Blunt, T. Földes, E. Rosta, and J. J. Baumberg, Collective mid-infrared vibrations in surface-enhanced Raman scattering, Nano Lett. 22, 7254 (2022).
  33. See Supplemental Material at http://link.aps.org/supplemental/10.1103/txdw-nqvn for experimental methods, microscope characterization, and CW SERS spectra of mixed SAMs, along with details of the theoretical dipole coupling model, fitting procedure of measured decays, and estimation of the cavity coupling strength.
  34. J. Nara, S. Higai, Y. Morikawa, and T. Ohno, Adsorption structure of benzenethiol on Au(1 1 1): First-principles study, Appl. Surf. Sci. 237, 434 (2004).
  35. A. Laubereau and W. Kaiser, Vibrational dynamics of liquids and solids investigated by picosecond light pulses, Rev. Mod. Phys. 50, 607 (1978).
  36. J. M. Marmolejos, P. J. Bisson, and M. J. Shultz, Gold as a standard phase reference in complex sum frequency generation measurements, J. Chem. Phys. 150, 124705 (2019).
  37. W. Guo, B. Liu, Y. He, E. You, Y. Zhang, S. Huang, J. Wang, and Z. Wang, Plasmonic gold nanohole arrays for surface-enhanced sum frequency generation detection, Nanomater. Nanotechnol. 10, 2557 (2020).
  38. R. Arul, D.-B. Grys, R. Chikkaraddy, N. S. Mueller, A. Xomalis, E. Miele, T. G. Euser, and J. J. Baumberg, Giant mid-IR resonant coupling to molecular vibrations in sub-nm gaps of plasmonic multilayer metafilms, Light Sci. Appl. 11, 281 (2022).
  39. B. N. J. Persson and R. Ryberg, Dipole-coupling-induced line narrowing in adsorbate vibrational spectroscopy, Chem. Phys. Lett. 174, 443 (1990).
  40. B. N. J. Persson, F. M. Hoffmann, and R. Ryberg, Influence of exciton motion on the shape of optical absorption lines: Applications to vibrations at surfaces, Phys. Rev. B 34, 2266 (1986).
  41. M. Oftadeh, S. Naseh, and M. Hamadanian, Electronic properties and dipole polarizability of thiophene and thiophenol derivatives via density functional theory, Comput. Theor. Chem. 966, 20 (2011).
  42. E. Elliott, K. Bedingfield, J. Huang, S. Hu, B. de Nijs, A. Demetriadou, and J. J. Baumberg, Fingerprinting the hidden facets of plasmonic nanocavities, ACS Photonics 9, 2643 (2022).
  43. J. U. Nielsen, M. J. Esplandiu, and D. M. Kolb, 4-Nitrothiophenol SAM on Au(111) investigated by in situ STM, electrochemistry, and XPS, Langmuir 17, 3454 (2001).
  44. S. A. Lee and S. Link, Chemical interface damping of surface plasmon resonances, Acc. Chem. Res. 54, 1950 (2021).
  45. W. Zhu, R. Esteban, A. G. Borisov, J. J. Baumberg, P. Nordlander, H. J. Lezec, J. Aizpurua, and K. B. Crozier, Quantum mechanical effects in plasmonic structures with subnanometre gaps, Nat. Commun. 7, 11495 (2016).
  46. T. A. Ageeva, A. A. Bush, D. V. Golubev, A. S. Gorshkova, K. E. Kamentsev, O. I. Koifman, V. D. Rumyantseva, A. S. Sigov, and V. V. Fomichev, Porphyrin metal complexes with a large dipole moment, J. Organomet. Chem. 922, 121355 (2020).
  47. T. N. Olney, N. M. Cann, G. Cooper, and C. E. Brion, Absolute scale determination for photoabsorption spectra and the calculation of molecular properties using dipole sum-rules, Chem. Phys. 223, 58 (1997).
  48. S. A. Blanton, R. L. Leheny, M. A. Hines, and P. Guyot-Sionnest, Dielectric dispersion measurements of CdSe nanocrystal colloids: Observation of a permanent dipole moment, Phys. Rev. Lett. 79, 865 (1997).
  49. H. Xu et al., Dipole–dipole-interaction-assisted self-assembly of quantum dots for highly efficient light-emitting diodes, Nat. Photonics 18, 186 (2024).
  50. L. A. Jakob, A. Juan-Delgado, N. S. Mueller, S. Hu, R. Arul, R. A. Boto, R. Esteban, J. Aizpurua, and J. J. Baumberg, Optomechanical pumping of collective molecular vibrations in plasmonic nanocavities, ACS Nano 19, 10977 (2025).
  51. J. Jeong, H.-H. Shin, and Z. H. Kim, Unveiling the mechanism of plasmon photocatalysis via multiquantum vibrational excitation, ACS Nano 18, 25290 (2024).
  52. 10.17863/CAM.120068.

Outline

Information

Phys. Rev. Lett. 135, 076901– Published 15 August, 2025
  • Received 31 March 2025
  • Revised 25 June 2025
  • Accepted 15 July 2025
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation