Stabilizing dynamical localization in driven tunneling
  Dynamical localization of a tunneling system by means of an oscillating external field is examined for an arbitrary doublet of tunneling states. We show that the condition of an exact crossing of Floquet levels, required for localization in a symmetric system, can be substantially relaxed for tunneling systems with broken symmetry. This generalization equally applies to tunneling systems coupled to a dissipative environment. 
J. Stockburger, C.H. Mak (University of Southern California)