Spin transport in a unitary Fermi gas close to the BCS transition

Abstract

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.

arXiv comment9 pages, 10 figures

References in corpus (22)

• Universal Spin Transport in a Strongly Interacting Fermi Gas
• Exciton condensation and charge fractionalization in a topological insulator film
• Observation of spin Coulomb drag in a two-dimensional electron gas
• Coulomb Drag in the Exciton Regime in Electron-Hole Bilayers
• Electron-drag effects in coupled electron systems
• Anomalous Coulomb drag in electron-hole bilayers
• Evolution of the Normal State of a Strongly Interacting Fermi Gas from a Pseudogap Phase to a Molecular Bose Gas
• Collective oscillations of a Fermi gas in the unitarity limit: Temperature effects and the role of pair correlations
• Viscosity and Thermal Relaxation for a resonantly interacting Fermi gas
• Quantum mechanical limitations to spin diffusion in the unitary Fermi gas
• Renormalization Group Theory for the Imbalanced Fermi Gas
• Dynamic spin response of a strongly interacting Fermi gas
• Spin fluctuations, susceptibility and the dipole oscillation of a nearly ferromagnetic Fermi gas
• Density and spin response of a strongly-interacting Fermi gas in the attractive and quasi-repulsive regime
• Comparative Study of BCS-BEC Crossover Theories above $T_c$: the Nature of the Pseudogap in Ultra-Cold Atomic Fermi Gases
• Spin diffusion in Fermi gases
• Spin drag in an ultracold Fermi gas on the verge of a ferromagnetic instability
• Probing the topological exciton condensate via Coulomb drag
• Bragg Spectroscopy of Cold Atomic Fermi Gases
• Quantum quench dynamics of the Bose-Hubbard model at finite temperatures
• Spin drag Hall effect in a rotating Bose mixture
• Spin Drag in Ultracold Fermi Mixtures with Repulsive Interactions

Cited by in corpus (11)

• Mapping out spin and particle conductances in a quantum point contact
• Observation of quantum-limited spin transport in strongly interacting two-dimensional Fermi gases
• Cooper pairing above the critical temperature in a unitary Fermi gas
• Observation of the Leggett-Rice effect in a unitary Fermi gas
• Universal Spin Transport and Quantum Bounds for Unitary Fermions
• Unified description of dynamics of a repulsive two-component Fermi gas
• Mesoscopic spin transport between strongly interacting Fermi gases
• Strong-coupling corrections to spin susceptibility in the BCS-BEC crossover regime of a superfluid Fermi gas
• Precursor of Superfluidity in a Strongly Interacting Fermi Gas with Negative Effective Range
• Unified Boltzmann-transport theory for the drag resistivity close to a second-order phase transition
• Spin susceptibility and effects of a harmonic trap in the BCS-BEC crossover regime of an ultracold Fermi gas