Abstract-Integral equation technique for scatterers with mesoscopic insertions: Application to a carbon nanotube

M. V. Shuba, A. V. Melnikov, P. P. Kuzhir, S. A. Maksimenko, G. Y. Slepyan, A. Boag, A. Mosca Conte, O. Pulci, and S. Bellucci

https://journals.aps.org/prb/accepted/6107dO76Q9410a3e03fb802612edf10544872aa61

We present the electromagnetic scattering theory for a finite-length nanowire with embedded mesoscopic object. The theory is based on a synthesis of the integral equation technique of classical electrodynamics and the quantum transport formalism. We formulate Hall\'en type integral equations, where the canonical integral operators from wire antenna theory are combined with special terms responsible for the mesoscopic structure. The theory is applied to calculate the polarizability of a finite-length single-walled carbon nanotube (CNT) with a short low-conductive section (LCS) in the microwave and sub-terahertz ranges. The LCS is modeled as a multichannel two-electrode mesoscopic system. The effective resistive sheet impedance boundary conditions for the scattered field are applied on the CNT surface. It is shown that the imaginary part of the polarizability spectrum has three peaks. Two of them are in the terahertz range, while the third one is in the gigahertz range. The polarizability spectrum of the CNT with many LCSs has only one gigahertz peak which shifts to low frequencies as the number of the LCS increases. The physical nature of these peaks is explained, and potential applications of nanoantennas are proposed