[institut] SCL seminar: Ross McKenzie, Wednesday, August 31 at 14:00

[Darko Tanaskovic]

Dear colleagues,

You are cordially invited to the Scientific Computing Laboratory 
seminar, which will be held on Wednesday, August 31, at 14:00 in the 
library reading room “Dr. Dragan Popović" of the Institute of Physics 
Belgrade. The talk entitled

Absence of a quantum limit to the shear viscosity of strongly 
interacting fermion systems

will be given by

Prof. Ross McKenzie,
University of Queensland, Brisbane, Australia
condensedconcepts.blogspot.com

Abstract of the talk:

Are there fundamental limits to how small the shear viscosity of a 
macroscopic fluid can be? Could Planck’s constant and the Heisenberg 
uncertainty
principle determine that lower bound? In 2005 mathematical techniques 
from string theory and black hole physics (!) were used to conjecture a 
lower bound for the ratio of the shear viscosity to the entropy of all 
fluids. From both theory and experiment, this bound appears to be 
respected in ultracold atoms and the quark-gluon plasma.
However, we have shown that this bound is strongly violated in the “bad 
metal” regime that occurs near a Mott insulator, and described by a 
Hubbard model [1]. I will give a basic introduction to shear viscosity, 
the conjectured bounds, bad metals, and our results.

[1] N. Pakhira and R.H. McKenzie, Phys. Rev. B 92, 125103 (2015).


Best regards,
Darko Tanaskovic

Institute of Physics Belgrade
Pregrevica 118, 11080 Belgrade, Serbia
http://www.ipb.ac.rs/