2013/04/30 by Gabriel Wlazłowski, Piotr Magierski, Aurel Bulgac +1 · 2 citations
Mathematics · Physics and Astronomy · #Ab initio #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Fermi gas #Formalism (music) #Materials science #Mathematical analysis #Mathematical physics #Mathematics #Omega #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum mechanics #Quantum, superfluid, helium dynamics #Shear (geology) #Shear viscosity #Unitary state #Upper and lower bounds #Viscosity #cond-mat.quant-gas #hep-lat #nucl-th
paper · pdf · doi:10.1103/physreva.88.013639
published as Phys. Rev. A 88, 013639 (2013)
arxiv created 2013/07/31 · openalex publication_date 2013/07/31 · arxiv updated 2013/08/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We present an ab initio determination of the shear viscosity for the unitary Fermi gas based on finite temperature quantum Monte Carlo (QMC) calculations and the Kubo linear-response formalism. The results are confronted with the bound for the shear viscosity originating from hydrodynamic fluctuations. Assuming smoothness of the frequency dependent shear viscosity \ensuremathη(\ensuremathω), we show that the bound is violated in the low temperature regime and the violation occurs simultaneously with the onset of the Cooper pairing in the system. In order to preserve the hydrodynamic bound in QMC \ensuremathη(\ensuremathω) has to possess a sharp structure located in the vicinity of zero frequency which is not resolved by an analytic continuation procedure.