Theoretical Design of a Switchable Chiral Meta-atom in The Terahertz Band Using Phase Change Material

Abstract

The chirality of switchable meta-atom made of twisted phase change material (PCM) micro-rod dimers is studied in depth, with an emphasis on the vanadium dioxide(VO2) switching capabilities and achieving the maximum chirality of the suggested structure. We have presented a suitable algorithm for designing the chiral meta-atom by twisted VO2 rods using an analytical approach based on the coupled dipole approximation (CDA). The unique properties of rod-shaped particles have attracted attention because they can be easily modeled by ellipsoidal particles and solved using analytical methods. The results show that when VO2 is in its metallic state, the twisted rod dimers behave as a chiral meta-atom, and that circular dichroism is maximized at = L/2 and ψ = 45°. We also report that when VO2 is in its insulating state, the meta-atom is almost transparent to THz waves. Interparticle spacing, twist angles, and rod length are all important chirality parameters that are discussed separately in this paper.