“…Dirac and Weyl semimetals), which have common features characterized by some band(s) with linear dispersion in k-space near the Fermi level (Weng et al, 2016;Armitage et al, 2018). Owing to the exotic electronic structures in TMs, giant nonlinear responses can be usually expected, such as second harmonic generation (Wu et al, 2017;Patankar et al, 2018;Hamh et al, 2016), nonlinear Hall effect (Ma et al, 2019), and photogalvanic effect (PGE) (Guan et al, 2017;Li et al, 2017). Particularly, on the excitation of the femtosecond (fs) laser pulses, the ultrafast photocurrents and the associated electromagnetic wave emission in the terahertz (THz) regime have attracted enormous attention recently in TMs (Sirica et al, 2019;Gao et al, 2020;Rees et al, 2020;Ni et al, 2021;Braun et al, 2016).…”