A team led by Prof. Dr. Tobias Schätz, Professor of Atomic and Quantum Physics at the Institute of Physics at the University of Freiburg, Dr. Pascal Weckesser, Fabian Thielemann and colleagues, demonstrate magnetic Feshbach resonances between a single barium ion and lithium atoms at near absolute zero temperature. The researchers found that depending on the strength of the external magnetic field, the expansion of the ion and atoms can be controlled. "At these ultracold temperatures, the collisions between particles reveal their quantum mechanical nature," explains Schätz. "Our research has shown that we're learning a bit more about the possibilities for controlling the quantum mechanical properties of wave-particle duality." The group published their findings in the journal Nature.