Near-field study in graphene/hBN heterostructures

Graphene is proposed as one of the most promising candidates for novel plasmonic devices, owning to its versatile tunability and ultrafast operation speed. Although exciting results of graphene plasmonics have been obtained, there is keen interest in improving device quality to explore additional plasmon physics and functionalities. Here we present studies of surface plasmons in graphene/hBN devices using scanning near-field optical microscopy. We find that by using these high quality devices, plasmon dissipation rate can be greatly reduced. Moreover, we demonstrated ultrafast hot carriers induced plasmon dispersion in real space. Our study would be important for novel graphene plasmonic applications.