BUSCADOR RECOLECTA

S1 Linear-response frequency-domain TDDFT calculations for a planar free-electron metal slab S1.1 Ground-state calculations S1.2 Linear-response calculations S1.3 Reflection coefficient R(ω, kk), surface response function g(ω, kk), and Feibelman parameter d⊥(ω, kk) S2 Real-time TDDFT calculations of the optical response of a cylindrical nanowire S2.1 Ground-state calculations S2.2 Optical response S3 Surface-response formalism (SRF) for the optical response of a cylindrical nanowire S3.1 Induced potential and the Feibelman parameter S3.2 Plasmon resonances sustained by a cylindrical nanowire within the SRF S4 Multipolar polarizabilities of a cylindrical nanowire S4.1 General expressions of the multipolar polarizability and multipole moment S4.2 Multipolar polarizability within the SRF and the classical theory S4.3 Multipolar polarizability from TDDFT calculations S5 Assessing the robustness of the dispersive Feibelman parameter S5.1 Real-time TDDFT calculation of dcyl⊥(ω, m) S5.2 Comparison between the dispersive Feibelman parameter dcyl⊥(ω, m) calculated with TDDFT for different nanowire sizes and d⊥(ω, kk) calculated with TDLDA for the planar metal surface S6 Resonant frequency and width of the plasmon resonances, Peer reviewed

Theory and Simulation S1. Molecular Optomechanical Theory S1.1 Approximations in the Description of Molecular Optomechanical Interactions S1.2 Expressions for the SERS Spectra S1.3 Expressions for the Vibrational Population and Correlation S2. DFT Calculations of Raman-active Molecular Vibrational Modes S3. Plasmonic Response of the NPoM Nanocavity S3.1 Dyadic Green’s Function of Metal-Insulator-Metal Structure S4. Optomechanical Parameters: Vibrational Frequency Shift, Damping, Pumping, and Coupling Parameters S5. Simulations of the Experimental Results S5.1 Collective Vibrational Modes in SERS Spectrum S5.2 Evolution of the SERS signal with Increasing Laser Intensity S5.3 Dependence of the SERS signal on Molecular Positions S5.4 Dependence of the SERS signal on the Number of Molecules S6. Comparison of Continuum-field Model with Single-mode Model S7. Effective Description of Raman Lineshift and Analytic Estimates S8. Raman Redshift Contributions from Local Dipoles and NPoM Modes S9. Raman Redshift from Vibrational Anharmonicity, Supplementary Experimental Data S10. NPoM In-coupling Correction S11. Raw Data of Individual NPoMs S12. Reversibility of Saturation and Damage S13. Vibrational Pumping and Non-equilibrium Temperatures S14. SERS Saturation of Other Molecules S15. Additional Picocavity Data References, Peer reviewed

This repository contains research data for all figures of the manuscript. This includes optomechanical simulations of plasmonic nanocavities and experimental SERS spectra from both NPoM nanocavities and SPARK picocavities. All data are provided in .txt files, space separated, with columns labelled in first row. The data are organized in folders for each figure, with individual files for each figure panel containing data. All further information is contained in the captions of the manuscript., Engineering and Physical Sciences Research Council (2275079) EPSRC (2275079) Engineering and Physical Sciences Research Council (EP/N016920/1) Engineering and Physical Sciences Research Council (EP/L027151/1) Engineering and Physical Sciences Research Council (EP/L015978/1) European Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (829067) European Commission Horizon 2020 (H2020) Research Infrastructures (RI) (861950) European Commission Horizon 2020 (H2020) ERC (883703), Peer reviewed

Further details on the introduced concept, the experimental setup, additional CD, and reference measurements; further theory details about the chirality transfer., Peer reviewed

Expression for the circularly polarized fundamental field convenient for an analysis of nonlinear effects; definition of the charge multipoles in cylindrical coordinates and induced potential of the nanowire; analysis of the induced nonlinear near field; definition of the linear multipolar polarizabilities; discussion on the time-to-frequency Fourier transform used to analyze the time-dependent results of the TDDFT and to obtain the frequency-resolved quantities; classical nonretarded calculations of the linear response; extended discussion of the symmetry constraints for the bulk contribution to nonlinear polarization; derivation of the selection rules based on the nonlinear density response formalism; results showing magnetization of the nanowire by a circularly polarized fundamental field pulse; and discussion of the Friedel oscillations of the ground-state electron density (PDF). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at the fundamental frequency (n = 1) for circular polarization with SAM = 1 of the incoming field (MP4). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at the n = 2 harmonic for circular polarization with SAM = 1 of the incoming field (MP4). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at the n = 3 harmonic for circular polarization with SAM = 1 of the incoming field (MP4). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at n = 4 harmonic for circular polarization with SAM = 1 of the incoming field (MP4). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at the fundamental frequency (n = 1) for linear polarization of the incoming field (MP4). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at the n = 2 harmonic for linear polarization of the incoming field (MP4). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at the n = 3 harmonic for linear polarization of the incoming field (MP4). Time evolution of the charge density induced in the nanowire, δϱ(n)(r, t) = Re{δϱ(r, nΩ)e–inΩt }, at the n = 4 harmonic for linear polarization of the incoming field (MP4)., Peer reviewed

Supplementary Note 1. COMSOL Multiphysics simulations S1.1 Details of the numerical simulations S1.2 Permittivities used in the simulations Supplementary Note 2. EEL spectrum for different velocities of the electron beam Supplementary Note 3. Modes of the cylindrical nanoresonator Supplementary Note 4. Multipole decomposition S4.1 Electric dipole S4.2 Electric quadrupole S4.3 Partial scattering contributions of the multipoles moments Supplementary Note 5. Nanodisk fabrication Supplementary Note 6. Nanodisk thickness determination S6.1 Electron energy loss spectroscopy S6.2 Tilted-view STEM imaging S6.3 Optical reflection spectroscopy Supplementary Note 7. Chemical composition from energy dispersive X-ray spectroscopy (EDS) Supplementary Note 8. Experimental EEL spectra Supplementary Note 9. Analysis of anisotropy effects in anapole excitation Supplementary Note 10. Analysis of the anapole-exciton coupled system S10.1 Details of the incident electric field and the scattering channels S10.2 Anapole-exciton coupled system within TCMT S10.3 Reproducing the EEL spectra with TCMT S10.4 Parameters obtained from the TCMT results Supplementary Note 11. Substrate influence in anapole excitation References for Supplementary Information, Peer reviewed

Preparation procedures, physical and spectroscopic data for compounds 4a−m, 5a−h, 6h,n, 8a−f, 11, and 12., Peer reviewed

Preparation procedures and full characterization data for compounds 3a–c, 4a–c, and 9a. NMR spectra of 3a–c. Cyclic voltammogram analysis data. Gaussian output data of structures 5–7., Peer reviewed