Observation of an Efimov spectrum in an atomic system

Understand

In 1970 V.

• Efimov predicted a puzzling quantum-mechanical effect that is still of great interest today.
• He found that three particles subjected to a resonant pairwise interaction can join into an infinite number of loosely bound states even though each particle pair cannot bind.
• Interestingly, the properties of these aggregates, such as the peculiar geometric scaling of their energy spectrum, are universal, i.e.