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Quasiparticles as lumps in cold quantum soup

New experiment in supercooled Bose-Einstein-condensate opens possibilities of totally new parallel technology. A group of researchers at the Department of Physics and Astronomy at Aarhus University for the first time have implanted single atoms in a supercooled gas, discovering that socalled quasiparticles are formed in the gas. The result is published in Physical Review Letters 28. July 2016.

[Translate to English:] Forsøgsopstillingen på IFA. Det kritiske øje tilhører medforfatter Lars Wacker

 

New quasiparticle created in cold quantum matter

All over nature, elementary particles interact with their environment. Electrons in a solid interact with their surroundings, which is essential for modern semi-conductor technology. Even elementary particles acquire their mass by the interplay with the renowned Higgs boson. Now, researchers at the Department of Physics and Astronomy, Aarhus University have developed a new approach to study these phenomena.

They insert impurities into ultracold quantum matter!

By cooling a small cloud of atoms close to absolute zero temperature a powerful scientific playground emerges – the Bose-Einstein-condensate – which provides an unmatched opportunity to study physics at the quantum level. By immersing impurity atoms into this quantum gas, the general scenario of a particle interacting with its environment can be studied in unprecedented detail.

Observing the interplay between an impurity and the condensate experimentally, the researchers found that the impurity disturbed its quantum surroundings to form a quasiparticle called a Bose polaron. This effect has also been observed in the familiar setting of an electron in a solid, but never in this type of versatile and pure quantum environment.

This novel experiment opens up exciting possibilities to mimic a number of other physical systems as well as to study entirely new physics. In the near future, this could lead to an increased understanding of superconductors or even provide knowledge as to why fundamental particles have mass.

The authors of PRL have selected this article to be a PRL Editors' Suggestion.  About one Letter in six is chosen for this highlighting.  They add: We look for papers that we judge to be particularly important, interesting, and well written. Suggestions are downloaded and cited about twice as often as the average Letter, and are covered in the press substantially more often.  Congratulations on your outstanding paper!

A link to the Physical Review Letters paper is here.

Physical Review Letters deem this discovery important enough to have asked the French researcher Frédéric Chevy to write a viewpoint article explaining some more aspects of the discovery.