High-frequency rectifiers based on type-II Dirac fermions

The advent of topological semimetals enables the exploitation of symmetry-protected topological phenomena and quantized transport. Here, we present homogeneous rectifiers, converting high-frequency electromagnetic energy into direct current, based on low-energy Dirac fermions of topological semimetal-NiTe2, with state-of-the-art efficiency already in the first implementation. Explicitly, these devices display room-temperature photosensitivity as high as 251mAW(-1) at 0.3THz in an unbiased mode, with a photocurrent anisotropy ratio of 22, originating from the interplay between the spin-polarized surface and bulk states. Device performances in terms of broadband operation, high dynamic range, as well as their high sensitivity, validate the immense potential and unique advantages associated to the control of nonequilibrium gapless topological states via built-in electric field, electromagnetic polarization and symmetry breaking in topological semimetals. These findings pave the way for the exploitation of topological phase of matter for high-frequency operations in polarization-sensitive sensing, communications and imaging. High-frequency rectifiers at terahertz regime are pivotal components in modern communication, whereas the drawbacks in semiconductor junctions-based devices inhibit their usages. Here, the authors report electromagnetic rectification with high signal-to-noise ratio driven by chiral Bloch-electrons in type-II Dirac semimetal NiTe2-based device allowing for efficient THz detection.

Automated summary

Researchers have developed homogeneous rectifiers based on topological semimetal-NiTe2, converting high-frequency electromagnetic energy into direct current with high efficiency. These devices demonstrate room-temperature photosensitivity and performance, validating the potential of controlling nonequilibrium topological states for high-frequency operations and sensitive sensing applications.