Observation of Spin Superfluidity in a Bose Gas Mixture
Authors: Fava E., Bienaimé T., Mordini C., Colzi G., Qu C., Stringari S., Lamporesi G., Ferrari G.
Autors Affiliation: INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, 38123 Povo, Italy; Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy
Abstract: The spin dynamics of a harmonically trapped Bose-Einstein condensed binary mixture of sodium atoms is experimentally investigated at finite temperature. In the collisional regime the motion of the thermal component is shown to be damped because of spin drag, while the two condensates exhibit a counterflow oscillation without friction, thereby providing direct evidence for spin superfluidity. Results are also reported in the collisionless regime where the spin components of both the condensate and thermal part oscillate without damping, their relative motion being driven by a mean-field effect. We also measure the static polarizability of the condensed and thermal parts and we find a large increase of the condensate polarizability with respect to the T=0 value, in agreement with the predictions of theory.
Journal/Review: PHYSICAL REVIEW LETTERS
Volume: 120 (17) Pages from: 170401-1 to: 170401-6
KeyWords: spin mixture; spin superfliudity; thermal effectDOI: 10.1103/PhysRevLett.120.170401Citations: 28data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-17References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here