Broadside-coupling-enabled insulator-to-metal transition in a terahertz metasurface

We theoretically demonstrate stacked-dipole-resonators-based (broadside near-field coupling configuration) multilayer metasurfaces separated by a vanadium dioxide film to achieve stronger field confinement in the spacer (VO2) region. Under relatively intense terahertz excitation (20 Vm(-1)) assisted by larger area electric field confinement, insulator-to-metal transition (IMT) in VO2 spacer is realized resulting in frequency (dipole mode) and amplitude (Fano mode) tunable metasurfaces. Enhancement in probing THz field triggers much stronger field confinement (10(7) Vm(-1)) inside the spacer layer leading to increased VO2 conductivity (responsible for IMT) through the Poole-Frankel effect. Such broadside coupled IMT-based terahertz metamaterials can help in realizing active meta devices for THz domain. Copyright (C) 2022 EPLA

Automated summary

This study demonstrates the use of stacked dipole resonators and a vanadium dioxide film to achieve stronger field confinement and tunable metasurfaces in the terahertz frequency range. The insulator-to-metal transition in the vanadium dioxide spacer layer is realized under intense terahertz excitation, leading to adjustable frequency and amplitude metasurfaces. The enhanced field confinement triggers increased conductivity in the vanadium dioxide layer, enabling the development of active metamaterial devices in the terahertz domain.