Thanks to new technology, it is possible to retain individual atoms, move them in a targeted manner or change their condition. Kaiserslautern physicists also work with this system. In a recent study, they investigated the consequences of the collision of two atoms in a weak magnetic field at low temperature. For the first time they have discovered that atoms, carrying their angular momentum in individual packets (quanta), thereby exchange two packets. It was also shown that the interaction strength between the atoms can be controlled. This is of interest for investigating chemical reactions, for example. The paper was published in the journal Physical Review Letters.