Finite-temperature collective dynamics of a Fermi gas in the BEC-BCS crossover.
We report on experimental studies on the collective behavior of a strongly interacting Fermi gas with tunable interactions and variable temperature. A scissors mode excitation in an elliptical trap is used to characterize the dynamics of the quantum gas in terms of hydrodynamic or near-collisionless behavior. We obtain a crossover phase diagram for collisional properties, showing a large region where a nonsuperfluid strongly interacting gas shows hydrodynamic behavior. In a narrow interaction regime on the BCS side of the crossover, we find a novel temperature-dependent damping peak, suggesting a relation to the superfluid phase transition.
Wright
M J
MJ
Institut für Experimentalphysik und Forschungszentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
Riedl
S
S
Altmeyer
A
A
Kohstall
C
C
Guajardo
E R Sánchez
ER
Denschlag
J Hecker
JH
Grimm
R
R