Quantum mechanics predicts that the vacuum, where light and matter is absent, contains energy. This phenomenon is known as quantum fluctuations and gives rise to spontaneous emission, creation of virtual particles, and perhaps even the large-scale structure of the universe and its expansion. However, it is typically challenging to study quantum fluctuations in detail.

Nils Byg Jørgensen, Georg Bruun, and Jan Arlt have conceived a new approach to study quantum fluctuations: by utilizing atoms cooled down to absolute zero temperature. Quantum fluctuations give rise to a certain interaction between ultracold atoms, but it is difficult to observe since other forces are far stronger. Now, there is a solution to this problem. The interactions between cold atoms can be tailored by adjusting the magnetic field. It turns out that at a certain magnetic field, the normal interactions of the system disappear, while only quantum fluctuations remain. This trick allows quantum fluctuations in unprecedented detail, providing new knowledge on the laws of nature, which govern our world.

The study is published in Physical Review Letters of 26 October 2018 in a paper titled Dilute Fluid Governed by Quantum Fluctuations