Controlling atom-atom interaction at ultralow temperatures by dc electric fields

We propose a physical mechanism for tuning the atom-atom interaction strength at ultra-low 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 multi-channel scattering calculations reveal features never before discussed for ultra-cold 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 (BEC) and on the pursuit for atomic degenerate fermion gases will be discussed.