NUMERICAL QUANTUM PROPAGATION WITH TIME-DEPENDENT HAMILTONIAN

A numerical method was proposed to propagate the quantum system with a time-dependent Hamiltonian. The propagator is composed of the time-in dependent-Hamiltonian-type multisplit forms, which becomes possible by realizing that the evolution operator has a close link with the time- shift operator. The present algorithm can achieve a high order of accu racy through the recurrence of multisplit forms with predetermined coe fficients, and it has the advantage that only the Hamiltonian itself a t different time instants is involved, while other currently available schemes need to perform either a time integration or a time different ial of the Hamiltonian. This essential difference has made our proposa l highly competitive. A one-dimensional model system is considered to verify the accuracy and efficiency of the numerical scheme. (C) 1996 A merican Institute of Physics.