Work

Magnetic Weyl semimetal terahertz detector with field-tunable hyperbolic structures for 6G communications operating at a single frequency of 0.1 THz

Year: 2025

Type: article

Abstract: • A terahertz detector with a spiral array of field - effect transistors in a hyperbolic architecture is developed, improving response time and sensitivity remarkably. • Magnetic Weyl semimetal Co 3 Sn 2 S 2 is used. Its properties boost photocurrent, and with magnetic field modulation, responsivity increases and noise equivalent power drops. • Ultra - high resolution 3D printing for microstructures and magnetron sputtering for Co 3 Sn 2 S 2 films ensure precise control, enabling high - performance terahertz wave photodetection. The realization of high-performance terahertz detection in 6G communications is fundamentally constrained by the noise-responsivity trade-off inherent to conventional optical/electric field-modulated sensors. We address this challenge through a groundbreaking integration of magnetic Weyl semimetal physics and hyperbolic spiral field-effect transistor architectures, enabled by weak magnetic field modulation. Measurements were performed at a single sub-terahertz frequency. Leveraging the unique linear band dispersion and type-II Weyl node characteristics of Co₃Sn₂S₂ nanofilms, we demonstrate a detector achieving record responsivity (3.99 × 10⁵ V/W) and noise equivalent power (256 pW/Hz¹ / ²). The device exploits dynamic spin-filter effects to amplify photoexcited carrier momentum while utilizing 3D-printed subwavelength hyperbolic structures (150 μm periodicity) to confine surface localized surface plasma (LSP), synergistically suppressing dark current and enhancing light-matter interaction. Fabricated through magnetron-sputtered crystalline films combined with two-photon-polymerized microcavities, this work establishes a new paradigm for terahertz signal regulation. By resolving the critical sensitivity-bandwidth conflict through magnetic-field-engineered carrier dynamics, our approach paves the way for practical implementation of low-noise terahertz communication nodes in 6G networks.

Source: Results in Engineering

DOI: 10.1016/j.rineng.2025.107735