VARIABLE TIME-STEP INTEGRATOR FOR INTENSE FIELD-DYNAMICS

A modification of the well-known Lanczos algorithm is described that adapts the method to explicitly timedependent solutions of the Schr6dinger equation. This technique possesses the desirable feature of variable timestep integration, thus eliminating the difficulties associated with fixed time-step integration schemes. Results are presented for a one-dimensional system: the so-called soft Coulomb potential in the presence of a harmonic electromagnetic field. It is demonstrated that the Lanczos propagation scheme can be efficiently and accurately used from the perturbative limit to the strong-field limit. © 1990 Optical Society of America.