A class of kinetically constrained models with reflection symmetry is proposed as an extension of the Fredrickson-Andersen model. It is proved that the proposed model on the square lattice exhibits a freezing transition at a non-trivial density. It is conjectured by numerical experiments that the known mechanism of the singular behaviors near the freezing transition in a previously studied model (spiral model) is not responsible for that in the proposed model.
KeywordsLattice theory and statistics · Theory and modeling of the glass transition · Percolation PACS 05.50.+q · 64.70.Q-· 64.60.ah
IntroductionAthermal particles with repulsive interactions exhibit rigidity with an amorphous structure when the density of the particles is higher than a critical value. Such a phenomenon is referred to as a jamming transition, and elucidation of the nature of jamming transitions is a challenging problem in statistical physics [1,2,3,4,5,6,7,8]. Thus far, the replica theories and the related cavity methods for equilibrium glass models have provided insights into jamming transitions as well as glass transitions [9,10]. As a different approach, kinetically constrained models (KCMs), which were investigated with a physical picture that glassy dynamics is purely kinematic [11,12,13], have been considered for understanding jamming transitions [14]. A particular property of KCMs is the absence of singularities in the equilibrium properties. Nevertheless, dynamical phase transitions in KCMs on Bethe lattices have been known to be strongly connected to a certain dynamical phase transition called a freezing transition in equilibrium glass models [15]. Also, recent studies have attempted to reveal the relationship between KCMs and glass-forming materials [16,17].Let us review theoretical studies on KCMs in brief. Here, we generally call dynamical phase transitions in KCMs freezing transitions, which mean the transition from an equilibrium phase to a frozen phase where an infinite number of particles are at rest as a result of blocking by other particles. The first proof for the existence of a freezing transition was presented for the Fredrickson-Andersen (FA) model and then also the Kob-Andersen model on a Bethe lattice [18,19]. However, for these models in finite dimensions, it has been shown that there are no true phase transitions [19,20], even though the numerical simulations have shown an indication of a transition. Then, it has been proved that a KCM, which is called spiral model, exhibits a freezing transition in two dimensions [21,22], leading to the concept of universality classes (we call that of the spiral model spiral class) for finite-dimensional freezing transitions.