The realization of free-electron radiation in the terahertz band with both compact device size and tunability is challenging. Prof. Fang Liu’s group realize terahertz Cherenkov radiation using a free electron beam passing on graphene-based hyperbolic metamaterial, and an on-chip integrated terahertz source that can be continuously tuned from 3.2 to 14 THz. This work not only experimentally realizes terahertz Cherenkov radiation but also achieves device integration and wide-range tunability, and provides a pathway toward miniaturized free electron terahertz sources.

Li Tianchang (Postdoc) and Professor Liu Fang are co first authors of this work; Professor Liu Fang and Professor Huang Yidong are co corresponding authors.

See the article: 

Li, T., Liu, F., Chen, Y. et al. On-chip Cherenkov radiation tuning in 3.2-14 THz. Nat Commun 16, 7921 (2025). https://doi.org/10.1038/s41467-025-63368-4