Activated Dynamics and Effective Temperature in a Steady State Sheared Glass

Abstract

We conduct nonequilibrium molecular dynamics simulations to measure the shear stress sigma, the average inherent structure energy E{IS}, and the effective temperature T{eff} of a sheared model glass as a function of bath temperature T and shear strain rate gamma. For T above the glass transition temperature T0, the rheology approaches a Newtonian limit and T{eff}-->T as gamma-->0, while for T<T0, sigma approaches a yield stress and T{eff} approaches a limiting value near T0. In the shear-dominated regime at high T, high gamma or at low T, we find that sigma and E{IS} each collapse onto a single curve as a function of T{eff}. This indicates that T{eff} is controlling behavior in this regime.