title: Experimental realization of an incompressible Newtonian fluid in two dimensions.
abstract: The Brownian diffusion of micron-scale inclusions in freely suspended smectic-A liquid crystal films a few nanometers thick and several millimeters in diameter depends strongly on the air surrounding the film. Near atmospheric pressure, the three-dimensionally coupled film-gas system is well described by Hughes-Pailthorpe-White hydrodynamic theory but at lower pressure (p≲70 torr), the diffusion coefficient increases substantially, tending in high vacuum toward the two-dimensional limit where it is determined by film size. In the absence of air, the films are found to be a nearly ideal physical realization of a two-dimensional, incompressible Newtonian fluid.
authors: Department of Physics and the Soft Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors: Zhiyuan
authors: Z
authors: Qi
authors: Department of Physics and the Soft Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors: Cheol Soo
authors: CS
authors: Park
authors: Department of Physics and the Soft Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors: Matthew A
authors: MA
authors: Glaser
authors: Department of Physics and the Soft Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors: Joseph E
authors: JE
authors: Maclennan
authors: Department of Physics and the Soft Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
authors: Noel A
authors: NA
authors: Clark