Electrically Gated Carrier‐Dynamic Control of High‐ Q Dark Modes in Silicon‐Integrated Terahertz Metasurfaces

Electrically tunable terahertz metasurfaces are promising for dynamic filtering, switching, sensing, and imaging, yet their operation is often described phenomenologically without a quantitative link between carrier transport and resonant electromagnetic response. Here, we report a silicon‐integrated terahertz metasurface composed of junction‐based asymmetric split rings connected by microstrip lines. The symmetry‐broken design enables high‐ Q dark‐mode resonances through suppressed radiative loss, while the silicon substrate provides an electrically controllable carrier medium. Under DC current bias, the device exhibits continuous terahertz transmission modulation with a maximum modulation depth of 94.4%. Beyond experimental demonstration, a coupled multiphysics model combining semiconductor drift‐diffusion analysis and full‐wave electromagnetic simulation is developed to correlate electrical bias, Schottky‐contact‐induced carrier redistribution, Joule‐heating‐induced temperature increase, effective conductivity variation, and spectral modulation. The model reveals that the electrically reconfigurable response arises from the combined effects of carrier redistribution and temperature increase and provides quantitative guidance for device optimization. These results offer a practical and predictive route toward semiconductor‐integrated, electrically tunable high‐ Q terahertz metasurfaces for active photonic applications.