Probing the equilibrium dynamics of colloidal hard spheres above the mode-coupling glass transition Auteur(s): Brambilla G., El masri Djamel, Pierno Matteo, Berthier L., Cipelletti L., Petekidis George, B. Schofield Andrew (Article) Publié: Physical Review Letters, vol. 102 p.085703 (2009) Texte intégral en Openaccess : Ref HAL: hal-00323231_v2 PMID 19257755 Ref Arxiv: 0809.3401 DOI: 10.1103/PhysRevLett.102.085703 WoS: 000263816200034 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 290 Citations Résumé: 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, $\ta$, including equilibrium easurements above $\phi_{\rm c}$, 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 $\phi_{\rm c}$ and enters a new dynamical regime where $\ta$ 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 $\ta$, as found in molecular glass-formers close to the glass transition. Commentaires: 4 pages, 3 figures, published in PRL 102 085703 (2009) |