UNC Physics Colloquium

Laura Kim, Massachusetts Institute of Technology

Nanophotonic Interfaces to Control Plasmons and Spins

Abstract
Light-matter interactions enabled by photonic quasiparticles play a crucial role in observing ultrafast phenomena as well as enabling next-generation nanophotonic devices and quantum technologies. In the first part of the presentation, I will present the first experimental demonstration of a mid-infrared light-emitting mechanism, originating from an ultrafast coupling of optically excited carriers into hot plasmon excitations in graphene. Such emission processes produce gate-tunable, non-Planckian emission behavior that is not dictated by the free-space photonic density of states. This work provides a platform for achieving ultrafast, ultrabright, on-chip mid-infrared light sources. In the second part of the presentation, I will present a diamond resonant metasurface that can mediate efficient spin-photon interactions and enable a new type of quantum imaging system. This quantum metasurface containing nitrogen-vacancy (NV) spin ensembles achieves local field concentration over a micron-scale NV layer, and it coherently encodes information about the local magnetic field on spin-dependent phase and amplitude changes of near-telecom light. The projected performance makes the studied quantum imaging metasurface appealing for the most demanding applications such as imaging through scattering tissues and spatially resolved chemical NMR detection.