First-principles Predictor of the Location of Ergodic-Non-ergodic Transitions

Abstract

This letter presents a remarkably simple approach to the first-principles determination of the ergodic-non-ergodic transition in monodisperse colloidal suspensions. It consists of an equation for the long-time asymptotic value $\gamma$ of the mean squared displacement of the colloidal particles, whose finite real solutions signal the non-ergodic state, and determines the non-ergodic parameter $f(k)$. We illustrate its concrete application to three simple model colloidal systems, namely, hard-spheres, hard-spheres plus repulsive (screened Coulomb) Yukawa interaction, and hard-sphere plus attractive Yukawa tail. The results indicate that this is quite a competitive theory, similar in spirit to, but conceptually independent from, the well-known mode coupling theory.

5 pages, 4 figures