Is demagnetization an efficient optimization method?
  Demagnetization, commonly employed to study ferromagnets, has been proposed as the basis for an optimization tool, a method to find the ground state of a disordered system. Here we present a detailed comparison between the ground state and the demagnetized state in the random field Ising model, combing exact results in $d=1$ and numerical solutions in $d=3$. We show that there are important differences between the two states that persist in the thermodynamic limit and thus conclude that AC demagnetization is not an efficient optimization method. 
S. Zapperi, F. Colaiori, L. Dante, V. Basso, G. Durin, A. Magni, M. J.   Alava