Nonlocal Nonlinear Optics in Graphene and the Optics of Weyl Semimetals

Abstract

Theoretical models are constructed for various nonlocal nonlinear optical processes in graphene. Specifically, difference frequency generation of surface plasmon-polaritons in Landau quantized graphene; the generation of entangled surface plasmon-polariton-photon states and laser-driven paramatric instability via stimulated parametric down-conversion are explored. Difference generation and parametric down-conversion are three-wave mixing processes that are mediated by the nonlocal nonlinear (second-order) in-plane susceptibility.

Systematic theoretical studies of both the bulk and surface electromagnetic eigenmodes, or polaritons, in Weyl semimetals are developed. The tensors of the bulk and surface conductivity are presented. Information about the electronic structure of Weyl semimetals, such as position and separation of Weyl nodes, Fermi energy, and Fermi arc surface states, can be extracted from measurements of the dispersion, transmission, reflection, and polarization of electromagnetic waves.