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

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(VO
2
) 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 VO
2
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 VO
2
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 VO
2
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.