Increasing Quantum Degeneracy by Heating a Superfluid
Authors: Papoular DJ., Ferrari G., Pitaevskii L.P., Stringari S.
Autors Affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy; Kapitza Institute for Physical Problems, Kosygina 2, 119334 Moscow, Russia
Abstract: We consider a uniform superfluid confined in two compartments connected by a superleak and initially held at equal temperatures. If one of the two compartments is heated, a fraction of the superfluid will flow through the superleak. We show that, under certain thermodynamic conditions, the atoms flow from the hotter to the colder compartment, contrary to what happens in the fountain effect observed in superfluid helium. This flow causes quantum degeneracy to increase in the colder compartment. In superfluid helium, this novel thermomechanical effect takes place in the phonon regime of very low temperatures. In dilute quantum gases, it occurs at all temperatures below T-c. The increase in quantum degeneracy reachable through the adiabatic displacement of the wall separating the two compartments is also discussed.
Journal/Review: PHYSICAL REVIEW LETTERS
Volume: 109 (8) Pages from: 084501 to: 084501
More Information: We are grateful to S. Balibar for fruitful discussions. This work has been supported by ERC through the QGBE grant.DOI: 10.1103/PhysRevLett.109.084501Citations: 10data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-02-16References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here