Second order gradient ascent pulse engineering
  We report some improvements to the gradient ascent pulse engineering (GRAPE) algorithm for optimal control of quantum systems. These include more accurate gradients, convergence acceleration using the BFGS quasi-Newton algorithm as well as faster control derivative calculation algorithms. In all test systems, the wall clock time and the convergence rates show a considerable improvement over the approximate gradient ascent. 
P. de Fouquieres, S.G. Schirmer, S.J. Glaser, Ilya Kuprov
quant-ph math-ph math.MP