2025/12/20 by Line Jelver, Joel D. Cox, Jelver, Line +1
Engineering · Physics and Astronomy · #Plasmonic and Surface Plasmon Research #Nonlinear Photonic Systems #Topological Materials and Phenomena
paper · pdf · doi:10.1021/acsnano.5c20758
Plasmons in atomically thin materials offer a compelling route to trigger nonlinear light-matter interactions through extreme optical confinement in the two-dimensional (2D) limit. However, optical nonlocality in plasmons is typically associated with losses in the linear response regime. Here, we show that nonlocal effects mediate strong plasmon-assisted optical nonlinearity in electrically reconfigurable 2D heterostructures. Using atomistic simulations that capture quantum finite-size and nonlocal effects in the nonlinear plasmonic response of graphene and phosphorene nanoribbon dimers, we reveal how symmetry and inter-ribbon coupling shape harmonic generation processes in perturbative and high-harmonic regimes. Independent tuning of geometry and carrier density in nanoribbon heterostructures is shown to induce inter-ribbon plasmon hybridization, impacting inversion symmetry governing even-ordered nonlinear processes like second-harmonic generation. These results reveal design principles for the active and passive tuning of nonlinear plasmonic effects and enable selective enhancement of specific harmonic processes, establishing 2D heterostructures as a versatile platform for nonlinear nanophotonics.