New interactions seen in an ultracold gas
Cold atom experiments have revealed a novel interaction between pairs of particles that is mediated by a surrounding quantum gas. Georg Bruun describes the discovery in Nature News and Views.
![[Translate to English:] Figur: Fysikerne observerede en tiltrækkende vekselvirkning mellem Cs-atomer, der blev overført af en omgivende gas af Li-atomer. [Translate to English:] Figur: Fysikerne observerede en tiltrækkende vekselvirkning mellem Cs-atomer, der blev overført af en omgivende gas af Li-atomer.](/fileadmin/news_import/Georg_Bruun_artikel.png)
Mediated interactions play a key role in modern physics. For instance, the fundamental interactions between elementary particles are mediated by gauge bosons such as photons. Also, the attraction between electrons that leads to superconductivity in metals arises from the exchange of vibrations in the surrounding crystal lattice. Now, the first observation of a mediated interaction in an atomic gas has been reported. Given that atomic gases are powerful quantum simulators, this paves the way for a detailed study of the properties of mediated interactions in regimes never realized before.
The article in Nature News and Views can be found here: https://www.nature.com/articles/d41586-019-00988-z