Cooling-rate effects in a model of glasses.

Using Monte Carlo simulations we study cooling-rate effects in a three-dimensional Ising model with four-spin interactions. During coarsening, this model develops growing energy barriers, which at low temperature lead to very slow dynamics. We show that the characteristic zero-temperature length increases very slowly with the inverse cooling rate, similarly to the behavior of ordinary glasses. For computationally accessible cooling rates the model undergoes an ideal glassy transition, i.e., the glassy transition for a very small cooling rate coincides with a thermodynamic singularity. We also study the cooling of this model with a certain fraction of spins fixed. Due to such heterogeneous crystallization seeds, the final state strongly depends on the cooling rate. Only for a sufficiently fast cooling rate does the system end up in a glassy state, while slow cooling inevitably leads to a crystal phase.