Dual‐Field Enhanced Room‐Temperature Terahertz Detector via Magnetic Weyl Semimetal Metasurfaces

To improve the performance of room‐temperature terahertz detectors, particularly regarding sensitivity and noise characteristics, an innovative detector incorporating a sawtooth array fabricated through femtosecond‐laser direct writing is developed. This device integrates e localized surface plasma effect with the unique properties of a Weyl semimetal within a subwavelength structural framework. The application of a magnetic field combined with laser excitation further enhances carrier mobility, resulting in improved device performance and faster response times. At a frequency of 0.1 THz, the responsivity increases from 1.134 × 10⁵ to 1.192 × 10⁵ V/W, the noise‐equivalent power decreases from 0.436 to 0.414 pW Hz −1/2 , and the response time is reduced from 210 to 49 ms. Additionally, terahertz time‐domain spectroscopy reveals a distinct absorption feature at 0.1 THz, aligning with critical requirements for 6G communication systems. This design presents both a novel conceptual approach and a technological platform for the advancement of high‐performance terahertz detection technologies.