%0 Generic %1 zurak2023direct %A Zurak, Luka %A Wolff, Christian %A Meier, Jessica %A Kullock, René %A Mortensen, N. Asger %A Hecht, Bert %A Feichtner, Thorsten %D 2023 %K electrical modulation nano-optics near-field plasmon response surface %T Direct electrical modulation of surface response in a single plasmonic nanoresonator %U http://arxiv.org/abs/2307.01423 %X Classical electrodynamics describes the optical response of macroscopic systems, where the boundaries between materials is treated as infinitesimally thin. However, due to the quantum nature of electrons, interfaces acquires a finite thickness. To include non-classical surface effects in the framework of Maxwell's equations, surface-response functions can be introduced, also known as Feibelman $d$-parameters. Surface response impacts systems with strong field localization at interfaces, which is encountered in noble metal nanoparticles supporting surface plasmon polaritons. However, studying surface response is challenging as it necessitates sub-nanometer control of geometric features, e.g. the gap size in a dimer antenna, while minimizing uncertainties in morphology. In contrast, electrical gating is convenient since the static screening charges are confined exclusively to the surface, which alleviates the need for precise control over the morphology. Here, we study the perturbation of Feibelman $d$-parameters by direct electric charging of a single plasmonic nanoresonator and investigate the resulting changes of the resonance in experiment and theory. The measured change of the resonance frequency matches the theory by assuming a perturbation of the tangential surface current. However, we also observe an unforeseen narrowing in the resonance width when adding electrons to the surface of a plasmonic nanoresonator. These reduced losses cannot be explained by electron spill-out within the local-response approximation (LRA). Such an effect is likely caused by nonlocality and the anisotropy of the perturbed local permittivity. Our findings open up possibilities to reduce losses in plasmonic resonators and to develop ultrafast and extremely small electrically driven plasmonic modulators and metasurfaces by leveraging electrical control over non-classical surface effects.

@misc{zurak2023direct, abstract = {Classical electrodynamics describes the optical response of macroscopic systems, where the boundaries between materials is treated as infinitesimally thin. However, due to the quantum nature of electrons, interfaces acquires a finite thickness. To include non-classical surface effects in the framework of Maxwell's equations, surface-response functions can be introduced, also known as Feibelman $d$-parameters. Surface response impacts systems with strong field localization at interfaces, which is encountered in noble metal nanoparticles supporting surface plasmon polaritons. However, studying surface response is challenging as it necessitates sub-nanometer control of geometric features, e.g. the gap size in a dimer antenna, while minimizing uncertainties in morphology. In contrast, electrical gating is convenient since the static screening charges are confined exclusively to the surface, which alleviates the need for precise control over the morphology. Here, we study the perturbation of Feibelman $d$-parameters by direct electric charging of a single plasmonic nanoresonator and investigate the resulting changes of the resonance in experiment and theory. The measured change of the resonance frequency matches the theory by assuming a perturbation of the tangential surface current. However, we also observe an unforeseen narrowing in the resonance width when adding electrons to the surface of a plasmonic nanoresonator. These reduced losses cannot be explained by electron spill-out within the local-response approximation (LRA). Such an effect is likely caused by nonlocality and the anisotropy of the perturbed local permittivity. Our findings open up possibilities to reduce losses in plasmonic resonators and to develop ultrafast and extremely small electrically driven plasmonic modulators and metasurfaces by leveraging electrical control over non-classical surface effects.}, added-at = {2023-07-25T10:03:51.000+0200}, author = {Zurak, Luka and Wolff, Christian and Meier, Jessica and Kullock, René and Mortensen, N. Asger and Hecht, Bert and Feichtner, Thorsten}, biburl = {https://www.bibsonomy.org/bibtex/267e93d733942264c6efc35f1298ba83a/ep5optics}, interhash = {dbd787a7737de49194c03a606eec62cd}, intrahash = {67e93d733942264c6efc35f1298ba83a}, keywords = {electrical modulation nano-optics near-field plasmon response surface}, note = {cite arxiv:2307.01423Comment: 10 pages, 3 figures, 15 pages Supplementary}, timestamp = {2023-07-25T10:03:51.000+0200}, title = {Direct electrical modulation of surface response in a single plasmonic nanoresonator}, url = {http://arxiv.org/abs/2307.01423}, year = 2023 }