A non-Hermitian metasurface heterostructure in the terahertz regime

Abstract

This work presents calculations involving a non-Hermitian metasurface and heterostructure incorporating two-layer Ag split-ring resonators (SRRs) separated by an amorphous silica on a VO₂/GaAs substrate, within the terahertz regime. Specifically, this work compares the eigenvalues of the transmission and reflection spectra, as well as the spectra themselves, of the metasurface for when the VO₂ is in an insulating state versus conducting state, per the Drude model. The presence of sharp increases in transmission at around exceptional point as well as resonance dips in the reflection spectra are noted. With these effects, this configuration may be used in sensors or other high-sensitivity setups, while the shifting induced by the insulator-metallic transition may see usage in tunable structures and ferroelectrics.