Viscosity of strongly interacting quantum fluids: spectral functions and sum rules
Feb, 2010Citations per year
Abstract: (arXiv)
The viscosity of strongly interacting systems is a topic of great interest in diverse fields. We focus here on the bulk and shear viscosities of \emph{non-relativistic} quantum fluids, with particular emphasis on strongly interacting ultracold Fermi gases. We use Kubo formulas for the bulk and shear viscosity spectral functions, and respectively, to derive exact, non-perturbative results. Our results include: a microscopic connection between the shear viscosity and the normal fluid density ; sum rules for and and their evolution through the BCS-BEC crossover; universal high-frequency tails for and the dynamic structure factor . We use our sum rules to show that, at unitarity, is identically zero and thus relate to density-density correlations. We predict that frequency-dependent shear viscosity of the unitary Fermi gas can be experimentally measured using Bragg spectroscopy.Note:
- Published version
- 67.85.De
- 67.10.Jn
- 67.85.Lm
- fluid: quantum
- viscosity
- sum rule
- spectral representation
- Fermi gas
- strong interaction
- fluid: nonrelativistic
References(48)
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