|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'506'133
Articles rated: 2609
26 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Viscosity and scale invariance in the unitary Fermi gas | | Tilman Enss
; Rudolf Haussmann
; Wilhelm Zwerger
; | | Date: |
30 Jul 2010 | | Abstract: | We compute the shear viscosity of the unitary Fermi gas above the superfluid
transition temperature, using a diagrammatic technique that starts from the
exact Kubo formula. The formalism obeys a Ward identity associated with scale
invariance which guarantees that the bulk viscosity vanishes identically. For
the shear viscosity, vertex corrections and the associated Aslamazov-Larkin
contributions are shown to be crucial to reproduce the full Boltzmann equation
result in the high-temperature, low fugacity limit. The frequency dependent
shear viscosity $eta(omega)$ exhibits a Drude-like transport peak and a
power-law tail at large frequencies that is proportional to the Tan contact.
The weight in the transport peak is given by the equilibrium energy density,
consistent with a sum rule that has recently been derived by Taylor and
Randeria. Near the superfluid transition, the peak width is of the order $0.5,
T_F$, thus invalidating a quasiparticle description. The ratio $eta/s$ between
the static shear viscosity and the entropy density exhibits a minimum near the
superfluid transition temperature whose value is larger than the string theory
bound $hbar/(4pi k_B)$ by a factor of about seven. | | Source: | arXiv, 1008.0007 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER