Terahertz graphene-based tunable capacitance metamaterials with ultra-high amplitude modulation depth

By combining substrate-side, phase-cancelling reflection with monolayer graphene reconfigured as nanoscale tunable lateral capacitors within metasurface unit cells, terahertz amplitude modulation exceeding 40 dB at around 2 THz with 30 MHz reconfiguration speed is demonstrated under solid-state, room-temperature conditions. The design provides a scalable and practical platform for high-speed, large-dynamic-range terahertz communications, real-time imaging, and programmable photonic circuits.