Non-Perturbative Quantum Dynamical Decoupling
  Current dynamical control based on the bang-bang control mechanism involving various types of pulse sequences is essentially a perturbative theory. This paper presents a non-perturbative dynamical control approach based on the exact stochastic Schr\"odinger equation. We report our findings on the pulse parameter regions in which the effective dynamical control can be exercised. The onset of the effective control zones reflects the non-perturbative feature of our approach. The non-perturbative methods offer possible new implementations when several different parameter regions are available. 
Jun Jing, Lian-Ao Wu, J. Q. You, Ting Yu
quant-ph