Fast and Sensitive On-Chip Homo/Heterodyne Detection for Terahertz Communication and Imaging

Enhancing electromagnetic coupling to achieve interaction between light and matter is imperative to develop high-performance terahertz devices. Here, we report an ultrasensitive terahertz detector based on the quasi-one-dimensional, low-energy Dirac Fermions in the topological semimetal-TaNiTe5, integrated with an asymmetric bow-tie antenna to enhance field localization and directional light coupling. The device operates via photothermoelectric (PTE) effect, enabling self-powered, homo/heterodyne dual-mode detection across from millimeter to terahertz band. It achieves room-temperature operation at 0.435 THz with a responsivity of 0.77 A/W, a noise equivalent power (NEP) below 9.71 pW·Hz1/2, a specific detectivity (D*) of 1.03 × 1011 Jones, and a response time less than 20 ns. Furthermore, owing to the unique electronic band structure and excellent carrier dynamics characteristics of the semimetal-TaNiTe5, the device enables heterodyne mixing with a radio frequency (RF) bandwidth exceeds 108 GHz, accompanied by intermediate frequency (IF) bandwidth >26.5 GHz. Leveraging its excellent performance, we demonstrate its potential for sub-THz communications and high-quality imaging in terms of encrypted data-information exchange. Our work establishes a strategy for achieving chip-level integration with versatile abilities for communication, and imaging at terahertz band.