Magnetic bias field driven ferro- and antiferromagnetic semiconductors as double negative media for microwave and terahertz ranges

Abstract

In this work, a theoretical study of the backward electromagnetic waves (BEMWs) existing in the bigyrotropic left-handed media controlled by a magnetic bias field is presented. The bigyrotropic media are both longitudinally and transversely magnetized ferromagnetic (FM) or antiferromagnetic (AFM) semiconductors (SCs) with electric and magnetic loss. It is shown that the BEMWs are observed both in the microwave and terahertz frequency ranges, in which the effective material parameters of the FM or AFM SCs are double negative. We demonstrate the control of the BEMW dispersion characteristics not only by changing the magnetic bias field direction and strength, but also by variation a material magnetization and thickness, an electron concentration in a solid-state plasma, as well as the electric and magnetic loss.