Suppression of reflection from the grid boundary in solving the   time-dependent Schroedinger equation by split-step technique with fast   Fourier transform
  We present an approach to numerically solving the time-dependent Schroedinger equation and other parabolic equations by the split-step technique with fast Fourier transform, which suppresses the backreflection of waves from the grid boundaries with any specified accuracy. Most importantly, all known methods work well only for a narrow region of incident waves spectrum, and the proposed method provides absorption of any wave whose length is large enough in comparison with the size of absorption region. 
A. A. Gonoskov and I. A. Gonoskov