title: Activated bond-breaking processes preempt the observation of a sharp glass-glass transition in dense short-ranged attractive colloids.
abstract: We study-using molecular dynamics simulations-the temperature dependence of the dynamics in a dense short-ranged attractive colloidal glass to find evidence of the kinetic glass-glass transition predicted by the ideal mode coupling theory. According to the theory, the two distinct glasses are stabilized, one by excluded volume and the other by short-ranged attractive interactions. By studying the density autocorrelation functions, we discover that the short-ranged attractive glass is unstable. Indeed, activated bond-breaking processes slowly convert the attractive glass into the hard-sphere one, preempting the observation of a sharp glass-glass transition.
authors.affiliation: Dipartimento di Fisica, INFM UdR, Università di Roma La Sapienza, P.le A. Moro 5, I-00185 Rome, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Zaccarelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Foffi
authors.forename: Francesco
authors.initials: F
authors.lastname: Sciortino
authors.forename: Piero
authors.initials: P
authors.lastname: Tartaglia