High-responsivity room-temperature terahertz detector based on WTe ₂ /BP heterostructure with magneto-optical hybrid modulation

The development of terahertz (THz) detectors capable of reconciling high sensitivity, ambient-temperature operation, and ultrafast response remains a critical challenge for 6G communication. Here, we present a co-engineered THz detection that synergizes topological surface states of WTe₂ with anisotropic magneto-conductivity of black phosphorus, achieving a record responsivity (R_A) of 20.34 A/W at 0.1 THz, which is 2.1 times higher than single-material devices. Key to this advancement is a plasmonic sub-wavelength architecture fabricated via femtosecond laser direct writing, which enhances localized THz fields through tailored surface plasmon resonance, as validated by finite-difference time-domain simulations. A synchronized THz-pumped time-domain (THz-TDS) spectroscopy system resolves ultrafast carrier dynamics with 0.199 ps temporal precision, directly addressing 6G's demand for real-time signal processing. Under dual-field modulation (0.145 mT magnetic field and 445 nm optical excitation), the detector achieves a noise-equivalent power (NEP) of 2.39 pW/Hz^1/2 at 12 V bias, surpassing conventional electromagnetic induction well detectors by 105%. The methodology advances applications in 6G networks and hyperspectral imaging while providing a versatile tool for probing carrier kinetics in quantum materials, underscoring the transformative potential of co-design strategies in next-generation optoelectronics.