A Novel Method for Fast and Accurate Extraction of Surface Plasmon Modes in Periodic Arrays of Graphene Nanoribbons

This letter introduces a novel approach for extracting surface plasmon modes in periodic arrays of graphene nanoribbons. The method involves calculating the reflection and transmission coefficients of surface plasmons within the unit cell, which, in turn, allows for the determination of the plasmon mode's propagation constant in the periodic structure. This crucial calculation is achieved by computing the eigenvalues of a 2 x 2 transmission matrix at each frequency. The proposed method showcases accuracy across a broad range of junction widths, facilitating efficient and rapid band structure calculations for any desired frequency range by significantly reducing computational time and memory consumption. The obtained results are rigorously compared to the Reflection Pole Method (RPM), demonstrating a high level of agreement while showcasing the remarkable computational efficiency achieved by our proposed method, which significantly outperforms RPM in terms of speed.