Extinction efficiency and scattering asymmetry of a PEMC sphere illuminated by vortex electromagnetic waves

This study examines the scattering of the orbital angular momentum (OAM) carrying wave by perfect electromagnetic conductor (PEMC) sphere. The incident and scattered electromagnetic fields are expressed using vector spherical wave functions (VSWFs) and unknown field coefficients. A relation between the incident and scattered field coefficients is formulated by implementing the appropriate boundary conditions (BCs) at the surface of the PEMC sphere. Expressions related to the extinction efficiency and scattering asymmetry parameter are derived and computed. The influences of the size parameter of the sphere and the beam waist radius are analyzed. To check the convergence of the proposed work, the numerical results of the scattering efficiency for the vortex electromagnetic (VEM) wave (l=1)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(l=1)$$\end{document} and plane wave (l=0)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(l=0)$$\end{document} for the PEMC sphere are calculated and found to be satisfactory. This investigation provides sufficient information for exploring the electromagnetic scattering mechanism in the OAM domain regarding metamaterial structures.