Cooling rate dependence and dynamic heterogeneity below the glass transition in a Lennard-Jones glass

We investigate a binary Lennard-Jones mixture with molecular dynamics simul ations. We consider first a system cooled linearly in time with the cooling rate gamma. By varying gamma over almost four decades we study the influen ce of the cooling rate on the glass transition and on the resulting glass. We find for all investigated quantities a cooling rate dependence; with dec reasing cooling rate the system falls out of equilibrium at decreasing temp eratures, reaches lower enthalpies and obtains increasing local order. Next we study the dynamics of the melting process by investigating the most imm obile and most mobile particles in the glass. We find that their spatial di stribution is heterogeneous and that the immobile/mobile particles are surr ounded by denser/less dense cages than an average particle.