New method to directly probe the quantum collisions of individual atoms

Schematic of the Experiment. We collide a clock atom with atoms in another state (labeled |4, 4>). When the clock atoms collide, they experience a discrete jump, which is the difference of two s-wave phase shifts. The s-wave phase shifts can be measured with atomic-clock accuracy and give precise information about the atom-atom interactions. Credit: Kurt Gibble, Penn State