Saturation of a spin-1/2 particle by generalized local control

We show how to apply a generalization of local control design to the problem of the saturation of a spin-1/2 particle by magnetic fields in nuclear magnetic resonance. The generalization of local or Lyapunov control arises from the fact that the derivative of the Lyapunov function does not depend explicitly on the control field. The second derivative is used to determine the local control field. We compare the efficiency of this approach with that of the time-optimal solution that has recently been derived using geometric methods.