High-efficiency threshold-less Cherenkov radiation generation by a graphene hyperbolic grating in the terahertz band

Xiaoqiuyan Zhang, Min Hu, Zhuocheng Zhang, Yueying Wang, Tianyu Zhang, Xingxing Xu, Tao Zhao, Zhenhua Wu, Renbin Zhong, Diwei Liu, Yanyu Wei, Yubin Gong, Shenggang Liu