Universal description of 2D channel plasmons: from graphene and beyond

Introduction: Controlling and routing electromagnetic radiation below the diffraction limit is a key feature for future photonic-based circuitry. Here, we propose an alternative solution to conventional metal-based... [ view full abstract ]

Introduction: Controlling and routing electromagnetic radiation below the diffraction limit is a key feature for future photonic-based circuitry. Here, we propose an alternative solution to conventional metal-based plasmonics by exploiting the subwavelength localization and tunability of 2D  materials' plasmons  guided along a V-shaped triangular channel.

Methods: We present both a rigorous quasi-analytical theory and a simpler effective-index method (EIM) to describe the plasmonic eigenmodes and corresponding field distributions of 2D-covered triangular channels.

Results: We have found that the dispersion of 2D channel plasmons follows the same functional dependence as their flat-plasmons counterparts, but now scaled by a purely geometric factor in which all the information about the system's geometry is incorporated. In addition, we show that the solution of the EIM reduces to solving a Schrödinger-like equation, whose eigenvalue determines the plasmon dispersion.

Discussion: The plasmonic spectrum calculated using both methods agrees well with full-wave numerical simulations. The modal distributions for each of the channel's modes are also obtained. We believe our results pave the way for the emergence of customized photonic devices for subwavelength waveguiding and localization of light based on novel 2D materials.