A G-FDTD Method for Solving the Multi-Dimensional Time-Dependent Schrodinger Equation

Abstract

The Finite-Difference Time-Domain (FDTD) method is a well-known technique for the analysis of quantum devices. It solves a discretized Schrodinger equation in an explicitly iterative process. However, the method requires the spatial grid size and time step satisfy a very restricted condition in order to prevent the numerical solution from diverging. In this article, we present a generalized FDTD (G-FDTD) method for solving the multi-dimensional time-dependent Schrodinger equation, and obtain a more relaxed condition for stability when the finite difference approximations for spatial derivatives are employed. As such, a larger time step may be chosen. This is particularly important for quantum computations. The new G-FDTD method is tested by simulation of a particle moving in 2-D free space and then hitting an energy potential. Numerical results coincide with those obtained based on the theoretical analysis.