39K Bose-Einstein condensate with tunable interactions.
We produce a Bose-Einstein condensate of 39K atoms. Condensation of this species with a naturally small and negative scattering length is achieved by a combination of sympathetic cooling with 87Rb and direct evaporation, exploiting the magnetic tuning of both inter- and intraspecies interactions at Feshbach resonances. We explore the tunability of the self-interactions by studying the expansion and the stability of the condensate. We find that a 39K condensate is interesting for future experiments requiring a weakly-interacting Bose gas.
LENS and Dipartimento di Fisica, Università di Firenze, INFN and CNR-INFM, 50019 Sesto Fiorentino, Italy.
G
G
Roati
M
M
Zaccanti
C
C
D'Errico
J
J
Catani
M
M
Modugno
A
A
Simoni
M
M
Inguscio
G
G
Modugno