2011/03/11 by Ariel Sommer, Mark Ku, Martin W. Zwierlein +1
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Dipole #Fermi Gamma-ray Space Telescope #Fermi gas #Pauli exclusion principle #Quantum and electron transport phenomena #Spin (aerodynamics) #Spin polarization #Superfluidity #Topological Materials and Phenomena #Unitarity #cond-mat.quant-gas #cond-mat.str-el
paper · pdf · doi:10.1088/1367-2630/13/5/055009
published as New J. Phys.13, 055009 (2011) · 14 pages, 4 figures
arxiv created 2011/03/11 · openalex publication_date 2011/05/24 · arxiv updated 2015/03/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present measurements of spin transport in ultracold gases of fermionic 6 Li in a mixture of two spin states at a Feshbach resonance. In particular, we study the spin-dipole mode, where the two spin components are displaced from each other against a harmonic restoring force. We prepare a highly imbalanced, or polaronic, spin mixture with a spin-dipole excitation and we observe strong, unitarity-limited damping of the spin-dipole mode. In gases with small spin imbalance, below the Pauli limit for superfluidity, we observe strongly damped spin flow even in the presence of a superfluid core. This indicates strong mutual friction between superfluid and polarized normal spins, possibly involving Andreev reflection at the superfluid–normal interface.