Probing the Equilibrium Dynamics of Colloidal Hard Spheres above the Mode-Coupling Glass Transition

G. Brambilla, D. El Masri, M. Pierno, L. Berthier, L. Cipelletti, G. Petekidis, A. B. Schofield
2009 Physical Review Letters  
We use dynamic light scattering and computer simulations to study equilibrium dynamics and dynamic heterogeneity in concentrated suspensions of colloidal hard spheres. Our study covers an unprecedented density range and spans seven decades in structural relaxation time, , including equilibrium easurements above ϕ_ c, the location of the glass transition deduced from fitting our data to mode-coupling theory. Instead of falling out of equilibrium, the system remains ergodic above ϕ_ c and enters
more » ... new dynamical regime where increases with a functional form that was not anticipated by previous experiments, while the amplitude of dynamic heterogeneity grows slower than a power law with , as found in molecular glass-formers close to the glass transition.
doi:10.1103/physrevlett.102.085703 pmid:19257755 fatcat:3k7mp26adzhtrflefbzfjpszey