Energy transfer collision in a sample of cold Rydberg atoms

Summary form only given. Collisions with Rydberg atoms have been studied in depth both theoretically and experimentally in recent decades. One well-known collisional process involving two Rydberg atoms is called energy transfer collision, which has a unique characteristic, i.e., its cross-section can be tuned by a static electric field via the Stark effect. This collisional process has been studied with several alkalis, using thermal atoms deriving from an atomic beam. This thermal source, however, has some disadvantages. With the advent of the magneto-optical trap (MOT), cold samples of atoms can now be produced very simply. Several groups have recently succeeded in producing cold samples of Rydberg atoms in a MOT and have observed collisional processes. This achievement has opened up an entirely new field, in which several different experiments can be carried out. This paper reports, for the first time, on a time evolution experiment of energy transfer collisions using cold Rydberg atoms in a MOT.