  Active tuning and switching of electromagnetic properties of materials is of
great importance for controlling their interaction with electromagnetic waves.
Superconductors are the only natural materials that exhibit diamagnetic
switching at their critical temperatures. Here, we demonstrate a new class of
meta-surfaces with electrically-induced diamagnetic switching capability at
room temperature. Structural configuration of the subwavelength meta-molecules
determines their magnetic response to an external electromagnetic radiation. By
reconfiguration of the meta-molecule structure, the strength of the induced
magnetic field in the opposite direction to the external magnetic field is
varied and the diamagnetic state of the meta-surface is altered, consequently.
We demonstrate a significant change in the relative permeability and
permittivity of a custom-designed meta-surface with diamagnetic switching
capability at terahertz frequencies, enabling terahertz intensity modulation
with record high modulation depths and modulation bandwidths through a fully
integrated device platform at room temperature.
