Terahertz rectification by noncentrosymmetric plasmonic metasurface

The plasmon modes lacking the inversion symmetry can be excited by terahertz radiation on a noncentrosymmetric plasmonic metasurface formed by a two-dimensional electron system gated by a metal grating with an asymmetric unit cell. Excitation of the noncentrosymmetric plasmon mode leads to the terahertz rectification by generating a plasmon-photogalvanic current in the two-dimensional electron system. Strong terahertz photogalvanic response of the noncentrosymmetric plasmonic metasurface was predicted theoretically and demonstrated experimentally.