• H2020
• Excellent Science
• European Research Council

Researchers of the University of Innsbruck in Austria have succeeded in measuring a fundamental shock process between atoms and charged molecules at low temperatures.

The experiment into the quantum of rotation, part-funded by the European Research Council, saw only a single photon of energy transferred in the rotation of the molecule. As the atoms and molecules in a hot gas move rapidly and chaotically, coldness restricts increasingly disorderly movements. Temperatures close to absolute zero allow careful measurements.

Commenting, Daniel Hauser, the lead author of the study, said: “The results contribute to a better understanding of fundamental processes in various areas of research. In astrophysics, for example, you have to understand how the cooling behaviour of gas clouds works to explain how stars and planets form. Collisions, where the rotation is changed, play a central role.”

The experiment consists of an ion trap which allows the examination of cold charged molecules using lasers. Negatively charged hydroxide ions, which are composed of one atom of oxygen and one atom of hydrogen or deuterium, are captured in a trap, cooled to about 260°C, and then examined for several minutes.

The results have been published in the journal Nature Physics.