TY - JOUR
T1 - Observation of Spin Superfluidity in a Bose Gas Mixture
AU - Fava, Eleonora
AU - Bienaimé, Tom
AU - Mordini, Carmelo
AU - Colzi, Giacomo
AU - Qu, Chunlei
AU - Stringari, Sandro
AU - Lamporesi, Giacomo
AU - Ferrari, Gabriele
N1 - Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/4/24
Y1 - 2018/4/24
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevLett.120.170401
DO - 10.1103/PhysRevLett.120.170401
M3 - Article
C2 - 29756820
AN - SCOPUS:85046282474
SN - 0031-9007
VL - 120
JO - Physical Review Letters
JF - Physical Review Letters
IS - 17
M1 - 170401
ER -