Considering the hurdles of experiments with more than one atomic species, the temptation arises of rephrasing Arthur L. Schawlow: "Double-species Bose-Einstein condensates are condensates with one species too many". We think otherwise. Quantum mixtures allow the investigation of a wealth of genuinely quantum phenomena: mixed phases of superfluids and Mott insulators, impurities and polarons, chemistry at zero-temperature.

Fate of an impurity in a binary bosonic mixture

Together with Giacomo Bighin and Tommaso Macrì, we studied the problem of a mobile impurity immersed in a bosonic mixture. We focused on the experimental relevant case of a 41K−87Rb mixture, prepared in its ground-state, with the impurity consisting of a few 41K atoms in the second-lowest hyperfine state. We provided a compressive picture of the impurity across the mixture phase diagram. In the droplet phase, under realistic experimental conditions, we found exotic bound-states where the impurity localized either at the center or at the droplet surface. Our findings provide new insights for the study and detection of Bose polarons in collisionally stable and long-lived Bose mixtures such as the 41K-87Rb one.

G. Bighin et al.
Impurity in a heteronuclear two-component Bose mixture
Phys. Rev. A 106, 023301 (2022)

K/Rb people

Luca Cavicchioli
PhD Student
Chiara Fort
Scientific Staff
Massimo Inguscio
Scientific Staff
Francesco Minardi
Scientific Staff
Alessia Burchianti
Scientific staff
Former members:
Giovanni Barontini
Jacopo Catani
Stefano Conclave
Chiara D'Errico
Luigi De Sarlo
Giacomo Lamporesi
Paolo Maioli
Lorenzo Marconi
Sara Rosi
Devang S. Naik
Gregor Thalhammer

K/Rb contacts

For further information, request of material, job opportunities, please contact:

Alessia Burchianti
(burchianti@lens.unifi.it)