Free-Electron Light Source Based on Twisted $\alpha-\text{MoO}3$ Slab

Cherenkov radiation offers a promising route to realize the novel on-chip light sources that are highly desired in, e.g., Terahertz/X-ray frequencies. However, Cherenkov radiation generally suffers from low photon emission efficiency. In this work, we proposed a free-electron light source based on a twisted α-
$\text{MoO}_{3}$
slab. The flat-band moire hyperbolic plasmons can significantly enhance Cherenkov radiation, with the enhancement rate higher than that provided by conventional surface plasmons by one order of magnitude.