Electrodynamic response of dual-gated bilayer graphene using an on-chip terahertz platform

The electrodynamic response of quantum materials in the terahertz (THz) frequency range is essential for uncovering fundamental electronic properties, such as quasiparticle mass and scattering time, that govern emergent quantum phases. While on-chip THz time-domain spectroscopy (TDS) has been applied to van der Waals (vdW) heterostructures with single bottom gates, exploration with dual-gate configurations remains underdeveloped. Here, we present a novel on-chip THz TDS platform to map the THz reflection of a dual-gated bilayer graphene (BLG) device at cryogenic temperatures, offering independent control over charge carrier density and displacement field. Through simultaneous THz reflection and transport measurements, we resolve incompressible features, including moiré filling peaks arising from hBN/BLG alignment and track its time evolution. This experiment opens the door to future studies of spontaneous symmetry-breaking phases in BLG and other vdW systems, particularly at high displacement fields and low carrier densities.