Deciphering the origin of spin current in spintronic terahertz emitters and its imprint on their electromagnetic radiation via time-dependent density functional theoryRemoveAli Kefayati, Yafei Ren, M. Benjamin Jungfleisch, Lars Gundlach, John Q. Xiao, and Branislav K. NikolićPhys. Rev. B 111, L140415 (2025)