Graphene-Mediated Light-Matter Interaction

Advances in 2D materials have opened a wealth of possibilities for the control of emission and propagation of light on length scales much smaller than the wavelength of light. Graphene, with highly-confined electrostatically tunable plasmons, provides a strong platform for explore a number of avenues. We show that graphene that can increase the luminescence of erbium by 80%, can induce population inversion in a three-level system, speed up the response time by over an order of magnitude, and has modulation depth of up to 14 dB for luminescence. We experimentally demonstrated a tunable epsilon-near-zero metamaterial with a elliptic-to-hyperbolic transition. The device had been theorized for many years and we provide the first experimental realization. We explore the properties of an isotropic tunable 2D heterostructure composed of black phosphorus, hexagonal boron nitride, and graphene. These symmetry-breaking materials create an effective permittivity that is biaxially anistropic and tunable. This material supports tunable beam steering based on propagation of energy along the hyperbolic dispersion lines.