Speaker
Martin Zwierlein (MIT)
Description
We study spin transport in a two-state mixture of ultracold
Fermi gases near a Feshbach resonance. The strong
interactions lead to extremely slow relaxation of spin
currents. The relevant transport coefficients, the spin
conductivity and the spin diffusion coefficient, are
observed to attain universal minimal values, with the spin
diffusion being given by hbar/m, where m is the atomic mass.
The ratio of spin conductivity and spin diffusion
coefficient yields the spin susceptibility in these gases,
showing the Curie law at high temperatures and a departure
from the compressibility at low temperatures, that we
interpret as a signature for entering the Fermi liquid regime.