AUTHOR=Giannini Vincenzo TITLE=Plasmonics: Future and Challenges JOURNAL=Frontiers in Photonics VOLUME=1 YEAR=2020 URL=https://www.frontiersin.org/journals/photonics/articles/10.3389/fphot.2020.621510 DOI=10.3389/fphot.2020.621510 ISSN=2673-6853