Speaker
Description
A typical surface-enhanced Raman scattering (SERS) system relies on deeply subwavelength field localization in nanoscale plasmonic cavities to enhance both the excitation and emission of Raman-active molecules [1,2]. Here, we demonstrate that a germanium-vacancy (GeV) defect in diamond can efficiently mediate the excitation process, by acting as a bright atomic antenna [3]. At low temperatures, the GeV’s low dissipation allows it to be efficiently populated by the incident field, resulting in a thousand-fold increase in the efficiency of Raman scattering in the hybrid system comprising a GeV atomic antenna and a plasmonic nanoparticle [4]. Additionally, we show that atomic antenna-enhanced Raman scattering can be distinguished from conventional SERS by tracing the dependence of Stokes intensity on input power, and the pronounced antibunching of the Raman emission.
We also discuss a simpler setup, in which GeV atomic antennas localize light in diamond, driving and enhancing the Raman response of the diamond lattice, in what would be a solid-state analogue of the canonical experiment demonstrating plasmon-enhanced Raman scattering from a solution of molecules [5].
[1] Kneipp et al., Population pumping of excited vibrational states by spontaneous Surface-Enhanced Raman Scattering, Phys. Rev. Lett. 76, 2444 (1996).
[2] Itoh et al., Toward a New Era of SERS and TERS at the Nanometer Scale: From Fundamentals to Innovative Applications, Chem. Reviews 123, 1552 (2023).
[3] Li et al., Atomic optical antennas in solids, Nature Photonics 18, 1113 (2024).
[4] Schmidt et al., Molecular optomechanics with atomic antennas, ACS Photonics 12, 3014 (2025).
[5] Moskovits, Surface-enhanced spectroscopy, Rev. Mod. Phys. 57, 783 (1985).
