Extreme terahertz nonlinearities in undoped GaAs driven by ultrahigh near-fields in metamaterials

摘要

Local terahertz fields of multiple 10 MV/cm tailored in gold metamaterials drive electronic interband transitions in intrinsic GaAs. The bandgap exceeds the THz photon energy 400-fold. Photoluminescence microscopy maps the THz near-field distribution.