Analytical study of highly adjustable plasmonic modes in graphene-based heterostructure for THz applications

This paper aims to study the reflection characteristics of optical beams in a hybrid graphene–hexagonal boron nitride (hBN)–graphene structure, which has been located on SiO2-Si layers. An analytical model is presented to derive the reflection characteristics by using the transfer matrix method. The upper Reststrahlen band has been chosen as the studied frequency range. It is shown that the characteristics of the reflected beam can be effectively controlled by varying the chemical potential of graphene sheets. The obtained results represent a high value of the reflected group delay (τr=15.3ps\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\tau }_{r}=15.3 ps$$\end{document}) at the frequency of 24.9 THz. The presented investigation will be helpful to control the group delays of reflected beams and can be utilized for the design of innovative graphene–hBN devices in the mid-infrared wavelengths.