Activated bond-breaking processes preempt the observation of a sharp glass-glass transition in dense short-ranged attractive colloids

摘要

We study -- using molecular dynamics simulations -- the temperaturedependence of the dynamics in a dense short-ranged attractive colloidal glassto find evidence of the kinetic glass-glass transition predicted by the idealMode Coupling Theory. According to the theory, the two distinct glasses arestabilized one by excluded volume and the other by short-ranged attractiveinteractions. By studying the density autocorrelation functions, we discoverthat the short-ranged attractive glass is unstable. Indeed, activatedbond-breaking processes slowly convert the attractive glass into thehard-sphere one, preempting the observation of a sharp glass-glass transition.