Superfluidity versus Bloch oscillations in confined atomic gases.
We study the superfluid properties of (quasi) one-dimensional bosonic atom gases/liquids in traps with finite geometries in the presence of strong quantum fluctuations. Driving the condensate with a moving defect we find the nucleation rate for phase slips using instanton techniques. While phase slips are quenched in a ring resulting in a superfluid response, they proliferate in a tube geometry where we find Bloch oscillations in the chemical potential. These Bloch oscillations describe the individual tunneling of atoms through the defect and thus are a consequence of particle quantization.
Büchler
H P
HP
Theoretische Physik, ETH-Hönggerberg, CH-8093 Zürich, Switzerland.
Geshkenbein
V B
VB
Blatter
G
G