Repulsive shield between polar molecules
  We propose and analyze a technique that allows to suppress inelastic collisions and simultaneously enhance elastic interactions between cold polar molecules. The main idea is to cancel the leading dipole-dipole interaction with a suitable combination of static electric and microwave fields in such a way that the remaining van-der-Waals-type potential forms a three-dimensional repulsive shield. We analyze the elastic and inelastic scattering cross sections relevant for evaporative cooling of polar molecules and discuss the prospect for the creation of crystalline structures. 
A. V. Gorshkov, P. Rabl, G. Pupillo, A. Micheli, P. Zoller, M. D.   Lukin, H. P. B\"uchler