Broadside-coupling–enabled insulator-to-metal transition in a terahertz metasurface
Soumyajyoti Mallick, Dibakar Roy Chowdhury
Abstract
Abstract 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 (VO 2 ) region. Under relatively intense terahertz excitation (20 Vm −1 ) assisted by larger area electric field confinement, insulator-to-metal transition (IMT) in VO 2 spacer is realized resulting in frequency (dipole mode) and amplitude (Fano mode) tunable metasurfaces. Enhancement in probing THz field triggers much stronger field confinement inside the spacer layer leading to increased VO 2 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.