A general theoretical and experimental framework for nanoscale electromagnetism
Name
1901.03988.pdf
Description
Submitted version
Size
4.6 MB
Format
Unknown
Checksum (MD5)
25e9b1df81a80a7077d072b5ca80f4b2
Author(s)
Yang, Yi
Zhu, Di
Yan, Wei
Agarwal, Akshay
Zheng, Mengjie
Joannopoulos, John
Lalanne, Philippe
Christensen, Thomas
Berggren, Karl K
Soljacic, Marin
Date Issued
2019
Journal
Nature
Publisher
Springer Science and Business Media LLC
Version
Original manuscript
Abstract
© 2019, The Author(s), under exclusive licence to Springer Nature Limited. The macroscopic electromagnetic boundary conditions, which have been established for over a century1, are essential for the understanding of photonics at macroscopic length scales. Even state-of-the-art nanoplasmonic studies2–4, exemplars of extremely interface-localized fields, rely on their validity. This classical description, however, neglects the intrinsic electronic length scales (of the order of ångström) associated with interfaces, leading to considerable discrepancies between classical predictions and experimental observations in systems with deeply nanoscale feature sizes, which are typically evident below about 10 to 20 nanometres5–10. The onset of these discrepancies has a mesoscopic character: it lies between the granular microscopic (electronic-scale) and continuous macroscopic (wavelength-scale) domains. Existing top-down phenomenological approaches deal only with individual aspects of these omissions, such as nonlocality11–13 and local-response spill-out14,15. Alternatively, bottom-up first-principles approaches—for example, time-dependent density functional theory16,17—are severely constrained by computational demands and thus become impractical for multiscale problems. Consequently, a general and unified framework for nanoscale electromagnetism remains absent. Here we introduce and experimentally demonstrate such a framework—amenable to both analytics and numerics, and applicable to multiscale problems—that reintroduces the electronic length scale via surface-response functions known as Feibelman d parameters18,19. We establish an experimental procedure to measure these complex dispersive surface-response functions, using quasi-normal-mode perturbation theory and observations of pronounced nonclassical effects. We observe nonclassical spectral shifts in excess of 30 per cent and the breakdown of Kreibig-like broadening in a quintessential multiscale architecture: film-coupled nanoresonators, with feature sizes comparable to both the wavelength and the electronic length scale. Our results provide a general framework for modelling and understanding nanoscale (that is, all relevant length scales above about 1 nanometre) electromagnetic phenomena.
MIT Department
Massachusetts Institute of Technology. Research Laboratory of Electronics
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1038/S41586-019-1803-1
