Quantum Generation of Hot Plasmonic Electrons in a Fano Nanostructure: Pushing the Limits of Quantum Effects in Plasmonics

Exploring the mechanisms and potential of hot-electron (HE) generation is a crucial facet of contemporary nanooptics and nanoelectronics research. In this work, we examine the limits of localization and enhancement in HE generation, particularly in the context of photochemical processes such as hydrocarbon fuel synthesis. For this study, we developed a nonlinear, quantum, self-consistent formalism incorporating multipole Kreibig parameters. We employed a plasmonic trimer consisting of two broadband antenna nanoparticles (NPs) and a small “reactor” nanorod (NR) with a narrow resonance. In this Fano scheme, the total absorption of the NP–NR–NP trimer exhibits a pronounced Fano effect─specifically, a Fano dip. Notably, we observe a significant enhancement in HE generation when computing surface maps within the NR. We refer to this configuration as an HE Super-Generator. From a fundamental perspective, the proposed nanooptical regime─combining Fano interference with the antenna effect─represents a scenario approaching the practical upper limit of HE-based quantum effects achievable in plasmonics. Our findings point to a promising strategy for future optoelectronic and photochemical applications at the classical–quantum interface in plasmonic systems.