Terahertz Magnetospectroscopy Study of Superlattice Plasmonic Metasurface

In recent times, magnetotransport, spin-dependent scattering phenomenon has been observed in many magnetic multilayer systems. In this work, we have experimentally investigated the magnetic field-dependent magnetotransport phenomena in Al/Ni multilayer system operating in terahertz (THz) domain. Our experimental study shows that the THz peak amplitude modulation of around 15% along with the real part of conductivity is enhanced by 22% under 30 mT applied external magnetic field compared to the static case (0 mT field). Based on this knowledge, we have proposed a square shaped ring resonator-based THz metasurface comprising superlattice (Al/Ni) configuration. The proposed metasurface has shown magnetically tunable resonant THz transmissions for different magnetic field strengths varying from 0 to 30 mT. The reported findings can be useful in realizing non-contact detection techniques for low intensity external magnetic fields, magnetic storage devices as well as developing active THz devices exploiting the magnetospectroscopy concept.