Cold Cs Rydberg-gas interactions

We present calculations of potential curves for very high-n (89D) Cs Rydberg-atom pairs, including a background electric field. From these potentials, we show that energy transfer occurs at rates of similar to 30-70 MHz, background electric fields play an important role and dipole-dipole- and quadrupole-quadrupole-induced avoided curve crossings should lead to conversion of electronic to kinetic energy, n-changing collisions, and observable ultracold long-range Rydberg molecules.