2025/05/05 by Maxim Trushin, Trushin, Maxim
Engineering · Materials Science · #FOS: Physical sciences #Gold and Silver Nanoparticles Synthesis and Applications #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Optics (physics.optics) #Plasmonic and Surface Plasmon Research
paper · pdf · doi:10.48550/arxiv.2505.02358
openalex publication_date 2025/05/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Surface plasmon polaritons (SPPs) can be understood as two-dimensional light confined to a conductor-dielectric interface via plasmonic excitations. While low-energy SPPs behave similarly to photons, higher-frequency SPPs resemble surface plasmons. Electrically generating mid-range SPPs is particularly challenging because it requires compensating for momentum mismatch, a process conventionally achieved through inelastic electron transport in nanostructures. Here, we theoretically demonstrate that electrical SPP generation is possible by directly coupling electron-hole dipoles to the quantized SPP field across an insulating spacer without accompanying electron transport. This approach can be realized in plasmonic van der Waals heterostructures composed of strongly-biased monolayer graphene as the emitter, few-layer hexagonal boron nitride as the spacer, and silver (or gold) as the plasmonic material. In this configuration, graphene's remarkable ability to support a strongly non-equilibrium steady-state electron-hole population results in non-thermal, bias-tunable SPP emission that is uniform along the hBN/Ag interface, achieving a power conversion efficiency of up to 1% and a Purcell factor of up to 100. These findings pave the way for integrating photonic and electronic functionalities within a single two-dimensional heterostructure.