The WCS‐FDTD method for simulating graphene

Abstract

AbstractA weakly conditionally stable‐finite difference time‐domain (WCS‐FDTD) scheme to simulate graphene is developed. The Pade fit method is used to approximate the interband conductivity of graphene and introduced into the WCS‐FDTD method directly by using the auxiliary differential equation. The accuracy of the Pade method is verified, and the effect of chemical potential on the accuracy is discussed. The time step size in proposed method is only determined by one spatial cell size, so the computational efficiency of this method is considerably larger than those of the conventional FDTD method and implicit explicit‐finite (HIE)‐FDTD method. An infinite graphene sheet and a graphene‐based metal sheet are simulated by using presented method, and the results are compared with theoretical value and the numerical results of the conventional FDTD method and HIE‐FDTD method. Simulated results show that proposed WCS‐FDTD method has high accuracy, and compared with the FDTD method and HIE‐FDTD method, its computational time is largely shorted. Besides, the numerical example presents that the interband conductivity has important effect on the performance of the graphene at high‐frequency range, especially when the chemical potential is small.