Excitation Suppression Due to Interactions Between Microwave-Dressed   Rydberg Atoms
  Atom-atom interactions within a small volume were investigated through the excitation of ultracold Rb atoms. The application of microwaves enhances these interactions, causing the suppression of Rydberg state excitation. The suppression of Rydberg atom excitation was both qualitatively observed and quantitatively analyzed using a universal scaling law, giving a measure of the atom-atom interaction strength in agreement with theoretical prediction. 
E. Brekke, J. O. Day, and T. G. Walker
physics.atom-ph