Numerical solutions of the time‐dependent Schrödinger equation with position‐dependent effective mass

Abstract

AbstractNumerical solution of the time‐dependent Schrödinger equation with a position‐dependent effective mass is challenging to compute due to the presence of the non‐constant effective mass. To tackle the problem we present operator splitting‐based numerical methods. The wavefunction will be propagated either by the Krylov subspace method‐based exponential integration or by an asymptotic Green's function‐based time propagator. For the former, the wavefunction is given by a matrix exponential whose associated matrix–vector product can be approximated by the Krylov subspace method; and for the latter, the wavefunction is propagated by an integral with retarded Green's function that is approximated asymptotically. The methods have complexity per step with appropriate algebraic manipulations and fast Fourier transform, where is the number of spatial points. Numerical experiments are presented to demonstrate the accuracy, efficiency, and stability of the methods.