Out of equilibrium dynamics of the spiral model

We study the relaxation of the bi-dimensional kinetically constrained spiral model. We show that, due to the reversibility of the dynamic rules, any unblocked state fully decorrelates infinite times irrespective of the system being in the unjammed or the jammed phase. As a consequence, the evolution of any unblocked configuration occurs in a different sector of phase space from the one that includes the blocked equilibrium configurations at criticality and in the jammed phase. We argue that such out-of-equilibrium dynamics share many points in common with coarsening in the one-dimensional Ising model and we identify the coarsening structures that are, basically, lines of vacancies. We provide evidence for this claim by analyzing the behavior of several observables including the density of particles and vacancies, the spatial correlation function, the time-dependent persistence and the linear response.