Quantum transport in strongly correlated Fermi gases

Abstract

Transport in strongly correlated fermions cannot be understood by fermionic quasiparticles alone. We present a theoretical framework for quantum transport that incorporates strong local correlations of fermion pairs. These contact correlations add essential contributions to viscous, thermal and sound transport coefficients. The bulk viscosity, in particular, receives its dominant contribution from pair excitations. Moreover, it can be measured elegantly by observing the response to a time-dependent scattering length even when the fluid is not moving. Rapid changes of the scattering length drive the system far out of local equilibrium, and we show how it relaxes back to equilibrium following a hydrodynamic attractor before a Navier-Stokes description becomes valid.

8 pages, contribution to the Proceedings of the 2024 IHP symposium ''Open questions in the quantum many-body problem''

References in corpus (7)

• Thermodynamics of the BCS-BEC crossover
• Universal Quantum Viscosity in a Unitary Fermi Gas
• Viscosity and scale invariance in the unitary Fermi gas
• Quantum mechanical limitations to spin diffusion in the unitary Fermi gas
• Observation of the Leggett-Rice effect in a unitary Fermi gas
• Quantum critical transport in the unitary Fermi gas
• Feshbach Resonances and Medium Effects in ultracold atomic Gases