Visualization 1: An electrodynamics-Langevin dynamics (ED-LD) approach to simulate metal nanoparticle interactions and motion

Movie showing the trajectories of a 100-nm-diameter Ag nanoparticle that is illuminated with a focused Gaussian beam and one that has no incident source beam Originally published in Optics Express on 16 November 2015 (oe-23-23-29978

Ultraconfined Plasmonic Hotspots Inside Graphene Nanobubbles

We report on a nanoinfrared (IR) imaging study of ultraconfined plasmonic hotspots inside graphene nanobubbles formed in graphene/hexagonal boron nitride (hBN) heterostructures. The volume of these plasmonic hotspots is more than one-million-times smaller than what could be achieved by free-space IR photons, and their real-space distributions are controlled by the sizes and shapes of the nanobubbles. Theoretical analysis indicates that the observed plasmonic hotspots are formed due to a significant increase of the local plasmon wavelength in the nanobubble regions. Such an increase is attributed to the high sensitivity of graphene plasmons to its dielectric environment. Our work presents a novel scheme for plasmonic hotspot formation and sheds light on future applications of graphene nanobubbles for plasmon-enhanced IR spectroscopy