title: Frequency-dependent shear viscosity of a liquid two-dimensional dusty plasma.
abstract: The viscoelasticity of a two-dimensional (2D) liquid stronglycoupled dusty plasma is studied experimentally, without macroscopic shear. Positions and velocities of the dust particles, measured by video microscopy, are used as the inputs to the generalized Green-Kubo relation to obtain the complex viscosity η(ω). The real part of η(ω) (which corresponds to dissipation) diminishes gradually with frequency, while the imaginary part (which corresponds to elasticity) is peaked at a frequency below the 2D dusty plasma frequency. The viscoelastic approximation is found to accurately describe the 2D experimental results for η(ω), yielding the Maxwell relaxation time τ(M)=0.10 s. Results for η(ω) are compared to 2D molecular dynamics Yukawa simulations and to a previous experiment that was performed using an oscillating macroscopic shear.
authors.affiliation: Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA. yan-feng@uiowa.edu
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: J
authors.initials: J
authors.lastname: Goree
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
mesh_terms: D003198:Computer Simulation; D004391:Dust; D008956:Models, Chemical; D058626:Plasma Gases / Q000737:chemistry*; D012212:Rheology / Q000379:methods*; D033081:Shear Strength; D013499:Surface Properties; D014783:Viscosity
chemical_list: D004391:Dust; D058626:Plasma Gases