“…Fueled by the exciting opportunities offered by strong light-matter interactions, the field of plasmonics experienced an explosive growth in the last two decades, which empowered unsurpassed performance in deep-subwavelength concentration of light 1 – 3 . Significant progress has been made not only in device technologies such as plasmonic lenses 4 , 5 , plasmonic nanosensors and biosensors 6 , 7 , metamaterials and metasurfaces 8 – 10 , photovoltaics 11 , and near-field imaging 12 – 14 , but also in fundamentals of optical physics such as nonlinear optical resonances 15 , 16 , exotic constructive and destructive interferences 17 – 19 , optical beam manipulation 20 – 22 , and even optical cloaking and invisibility 23 , to name but a few. However, while offering extreme light confinement, plasmonic structures are challenging in terms of loss and greatly suffer from intrinsic absorption losses due to interband and intraband transitions in the visible and infrared regions, respectively.…”