Large heat-capacity jump in cooling-heating of fragile glass from kinetic Monte Carlo simulations based on a two-state picture

The specific-heat capacity cv of glass formers undergoes a hysteresis when subjected to a cooling-heating cycle, with a larger cv and a more pronounced hysteresis for fragile glasses than for strong ones. Here we show that these experimental features, including the unusually large magnitude of cv of fragile glasses, are well reproduced by kinetic Monte Carlo and equilibrium study of a distinguishable particle lattice model incorporating a two-state picture of particle interactions. The large cv in fragile glasses is caused by a dramatic transfer of probabilistic weight from high-energy particle interactions to low-energy ones as temperature decreases.