English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We provide a description of the dynamic structure factor of a homogeneousunitary Fermi gas at low momentum and low frequency, based on the dissipativetwo-fluid hydrodynamic theory. The viscous relaxation time is estimated and isused to determine the regime where the hydrodynamic theory is applicable and tounderstand the nature of sound waves in the density response near thesuperfluid phase transition. By collecting the best knowledge on the shearviscosity and thermal conductivity known so far, we calculate the variousdiffusion coefficients and obtain the damping width of the (first and second)sounds. We find that the damping width of the first sound is greatly enhancedacross the superfluid transition and very close to the transition the secondsound might be resolved in the density response for the transferred momentum upto the half of Fermi momentum. Our work is motivated by the recent measurementof the local dynamic structure factor at low momentum at Swinburne Universityof Technology and the on-going experiment on sound attenuation of a homogeneousunitary Fermi gas at Massachusetts Institute of Technology. We discuss how themeasurement of the velocity and damping width of the sound modes inlow-momentum dynamic structure factor may lead to an improved determination ofthe universal superfluid density, shear viscosity and thermal conductivity of aunitary Fermi gas.

Low-momentum dynamic structure factor of a strongly interacting Fermi gas at finite temperature: A two-fluid hydrodynamic description