A Drude-Two-CP-FDTD method for Drude-critical points model of metal nanofilms Jian-Xiao Liu, Yan Jiang, Ling-Hui Ming, Wan-Chun Tang and Hong-Wei Yang Eur. Phys. J. Plus, 135 10 (2020) 805 Published online: 10 October 2020 DOI: 10.1140/epjp/s13360-020-00824-8