Non-local effects in graphene plasmonic devices operating at short wavelength infrared frequencies

Abstract

Plasmons in graphene are known to be tunable and to exhibit extreme field confinement, making them useful for optoelectronic devices, and for exploring extreme light matter interactions. Thus far, these effects have been demonstrated at Thz to mid-IR frequencies, with the upper frequency limit set by limits of electron beam lithography, which can make graphene nanostructures as small as 15nm. In this talk, I will show that bottom-up block co-polymer lithography methods can create nanostructures with characteristic lengthscales as small as 12nm, and that in this regime the non-local interactions in graphene become strong, creating a significant blue shift of the plasmonic resonances. This allows for the creation of plasmonic cavities with resonances at wavelengths as short as 2.2um. The confinement factors of these cavities reach 135, which is exceedingly large, but less than what has been predicted by theory.