Controllable Excitation of Surface Plasmon Polaritons in Graphene‐Based Semiconductor Quantum Dot Waveguides

Abstract

The research aim of this study is the development of a theoretical semiclassical model of the controllable excitation and propagation of surface plasmon polaritons (SPPs) in planar graphene waveguides by the application of external voltage. The model is based on the numerical solution of the SPP's dispersion equation formulated for a system including two coupled graphene sheets with embedded quantum dots. Using the developed model, the different near-field patterns realized in the waveguides depending on the quantum dots' ordering and an external voltage applied independently to each graphene sheet with additional gold electrodes are numerically investigated. The obtained results show that the application of external voltage can locally change the chemical potential of graphene and, thereby, lead to controllable excitation of SPPs in the corresponding graphene waveguide. Furthermore, we revealed that the propagation direction of the excited SPPs is determined by the geometrical configurations of the gold electrodes that provide the required SPP routing. The investigated system offers new opportunities for near-field energy transport and concentration, which can be applied to develop ultra-compact photonic devices.

Interaction between Graphene Nanoribbon and an Array of QDs: Introducing Nano Grating

“…Achieving the dense integration of the waveguide systems is impossible considering the diffraction problem [4]. All-graphene-based technologies are suitable approaches to solve this problem because the electromagnetic field localizes well to graphene [10,11]. Recently, graphene, a one-atom-thick material, has been introduced as a plasmonic planar material [12,13].…”

“…Thus, graphene plasmons are an attractive and suitable alternative to noble metal plasmons because they show a relatively large distance for plasmon transmission. In addition, surface plasmons in graphene have the advantage of being regulated by electrostatic gates [10,14]. Compared to noble metals, graphene has extraordinary electronic and mechanical properties that originate in part from its zero-mass charge carriers [15].…”

“…Hybrid plasmonic structures, while combining the properties of dielectric and plasmonic waveguides, are designed to achieve high light confinement without including high losses [16]. Experimental research has expanded to include the fabrication and study of QD-graphene nanostructures [10,17]. These structures can make a significant contribution to the formation of plasmonic waveguides.…”

Analysis and Simulation of the Optical Properties of a Quantum Dot on a Graphene Nanoribbon System

“…The numerical simulations show that a periodic optical structure is obtained by placing quantum dots on a graphene nanoribbon in a periodic array. This idea could lead to several interesting applications in classical and quantum optical integrated circuits [5,6]. The massive oscillations of electrons cause surface plasmon polarization in graphene nanoribbons in the conduction band due to the dielectric difference between the graphene and the surroundings media.…”

“…Graphene plasmons are an attractive and suitable alternative to noble metal plasmons, because they show plasmon transport over a relatively long distance. In addition, the surface plasmons in graphene have the advantage of being regulated by electrostatic gates [5,9]. Compared to noble metals, graphene has extraordinary optical, electrical, and mechanical properties that originate in part from its zero-mass charge carriers [16].…”