TY - JOUR

T1 - Spin Transport in a Unitarity Fermi Gas Close to the BCS Transition

AU - Mink, M.P.

AU - Jacobs, V. P. J.

AU - Stoof, H.T.C.

AU - Duine, R.A.

AU - Polini, M.

AU - Vignale, G.

PY - 2012

Y1 - 2012

N2 - We consider spin transport in a two-component ultracold Fermi gas with attractive interspecies interactions close to the BCS pairing transition. In particular, we consider the spin-transport relaxation rate and the spin-diffusion constant. Upon approaching the transition, the scattering amplitude is enhanced by pairing fluctuations. However, as the system approaches the transition, the spectral weight for excitations close to the Fermi level is decreased by the formation of a pseudogap. To study the consequence of these two competing effects, we determine the spin-transport relaxation rate and the spin-diffusion constant using both a Boltzmann approach and a diagrammatic approach. The former ignores pseudogap physics and finite lifetime effects. In the latter, we incorporate the full pseudogap physics and lifetime effects, but we ignore vertex corrections, so that we effectively calculate single-particle relaxation rates instead of transport relaxation rates. We find that there is qualitative agreement between these two approaches, although the results for the transport coefficients differ quantitatively.

AB - We consider spin transport in a two-component ultracold Fermi gas with attractive interspecies interactions close to the BCS pairing transition. In particular, we consider the spin-transport relaxation rate and the spin-diffusion constant. Upon approaching the transition, the scattering amplitude is enhanced by pairing fluctuations. However, as the system approaches the transition, the spectral weight for excitations close to the Fermi level is decreased by the formation of a pseudogap. To study the consequence of these two competing effects, we determine the spin-transport relaxation rate and the spin-diffusion constant using both a Boltzmann approach and a diagrammatic approach. The former ignores pseudogap physics and finite lifetime effects. In the latter, we incorporate the full pseudogap physics and lifetime effects, but we ignore vertex corrections, so that we effectively calculate single-particle relaxation rates instead of transport relaxation rates. We find that there is qualitative agreement between these two approaches, although the results for the transport coefficients differ quantitatively.

U2 - 10.1103/PhysRevA.86.063631

DO - 10.1103/PhysRevA.86.063631

M3 - Article

SN - 1050-2947

VL - 86

SP - 1

EP - 8

JO - Physical review. A, Atomic, molecular and optical physics

JF - Physical review. A, Atomic, molecular and optical physics

IS - 6

M1 - 063631

ER -