Temporal damping of the axial breathing mode in a trapped unitary Fermi gas

The study of the strongly interacting Fermi systems is quite an important issue in physics covering the range from cold atoms to quark-gluon plasmas. The damping rate of the collective modes of the unitary Fermi gas is an important experimental observable. It varies with experimental conditions, and provides information about the viscosity. In this paper, we simulate the axial breathing modes basing on viscous hydrodynamics, and extract the concrete relation between the temporal damping rate and the experimental parameters: viscosity, atom number and the trap frequencies. The result shows that Γ equals 1.5*α0*N-1/3*Ωax5/3*Ωrad-2/3, where Γ is the damping rate, α0 is the dimensionless viscosity coefficient, N is the total number of atoms, Ωax and Ωrad are the trap axial and trap radial frequencies