Journal Article terahertz phase discontinuities Research Support, Non-U.S. Gov't coherent control diffraction metamaterials Metals Metasurfaces Pancharatnam-Berry phase optical element Review THz metasurface Vanadium dioxide asymmetric transmissions broadband broadband terahertz generation chirality complete control cost‐effective coupling‐controlled chiral meta‐atom dielectric dynamic metasurface geometric phase interfacial evaporator lignin metagratings metasurfaces near-field microscopy nonlinear metasurfaces non‐interleave