Four-wave mixing of topological edge plasmons in graphene metasurfaces

Abstract

We study topologically-protected four-wave mixing (FWM) interactions in a plasmonic metasurface consisting of a periodic array of nanoholes in a graphene sheet, which exhibits a wide topological bandgap at terahertz frequencies upon the breaking of time-reversal symmetry by a static magnetic field. We demonstrate that due to the significant nonlinearity enhancement and large lifetime of graphene plasmons in specific configurations, a net gain of FWM interaction of plasmonic edge states within the topological bandgap can be achieved with pump power of less than 10 nW. In particular, we find that the effective waveguide nonlinearity coefficient is about γ 1.1 × 10 13 W −1 m −1 , i.e., more than ten orders of magnitude larger than that of commonly used, highly nonlinear silicon photonic nanowires. These findings could pave a new way for developing ultra-low-power-consumption, highly-integrated and robust active photonic systems at deep-subwavelength scale for applications in quantum communications and information processing.

Valley-Hall Topological Plasmons in a Graphene Nanohole Plasmonic Crystal Waveguide

“…Moreover, graphene plasmons, the energy carriers in graphene based photonic systems, exhibit a tight optical field confinement and have long intrinsic relaxation times in the terahertz and up to mid-infrared frequency range [18]- [22]. Indeed, it has been shown that a periodically patterned graphene nanostructure under a static magnetic field can host topological one-way edge plasmons up to infrared frequencies [23]- [25], owing to the breaking of the time reversal symmetry.…”

Tunable and dual-broadband giant enhancement of second-harmonic and third-harmonic generation in an optimized graphene-insulator-graphene metasurface

“…In particular, it has been demonstrated that the strength of third-order nonlinear optical interactions in graphene is several orders of magnitude larger than in typical semiconductors [33][34][35][36]. More importantly, these nonlinear optical interactions can be further enhanced upon resonant excitation of SPPs in graphene structures, which leads to a number of exciting applications [18][19][20][37][38][39][40][41][42][43][44][45][46], including frequency mixing [18], photodetectors [25], generation of spatial solitons [43,44], physical systems with tunable Dirac points [45], and Anderson light localization at the nanoscale [46].…”

Four-wave Mixing of Topological Edge Plasmons in a Graphene Metasurface

“…These figures show the electric field calculated along the edge of the finite graphene plasmonic system, at a distance of 80 nm above the surface of the graphene metasurface. These results demonstrate that a net gain can be achieved when γ≤0.2 THz [6]. The main reason why this important phenomenon occurs is that the energy of the pump wave could be effectively transferred to the signal at a rate larger than the rate at which the signal power dissipates.…”