Controlling Atom-Atom Interaction at Ultralow Temperatures by dc Electric Fields

We propose a physical mechanism for tuning the atom-atom interaction strength at ultralow temperatures. In the presence of a dc electric field the interatomic potential is changed due to the effective dipole-dipole interaction between the polarized atoms. Detailed multichannel scattering calculations reveal features never before discussed for ultracold atomic collisions. We demonstrate that optimal control of the effective atom-atom interactions can be achieved under reasonable laboratory conditions. Implications of this research on the physics of atomic Bose-Einstein condensation and on the pursuit for atomic degenerate fermion gases will be discussed.