title: Experimental observations of dynamic critical phenomena in a lipid membrane.
abstract: Near a critical point, the time scale of thermally induced fluctuations diverges in a manner determined by the dynamic universality class. Experiments have verified predicted three-dimensional dynamic critical exponents in many systems, but similar experiments in two dimensions have been lacking for the case of conserved order parameter. Here we analyze the time-dependent correlation functions of a quasi-two-dimensional lipid bilayer in water to show that its critical dynamics agree with a recently predicted universality class. In particular, the effective dynamic exponent z(eff) crosses over from ~2 to ~3 as the correlation length of fluctuations exceeds a hydrodynamic length set by the membrane and bulk viscosities.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
authors.forename: Aurelia R
authors.initials: AR
authors.lastname: Honerkamp-Smith
authors.forename: Benjamin B
authors.initials: BB
authors.lastname: Machta
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Keller
mesh_terms: D008051:Lipid Bilayers / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry*; D008954:Models, Biological; D008956:Models, Chemical
chemical_list: D008051:Lipid Bilayers; D008563:Membrane Lipids