Energy Landscape and Metastability of Stochastic Ising and Potts Models on Three-dimensional Lattices Without External Fields

In this study, we investigate the energy landscape of the Ising and Potts models on fixed and finite but large three-dimensional (3D) lattices where no external field exists and quantitatively characterize the metastable behavior of the associated Glauber dynamics in the very low temperature regime. Such analyses for the models with non-zero external magnetic fields have been extensively performed over the past two decades; however, models without external fields remained uninvestigated. Recently, the corresponding investigation has been conducted for the two-dimensional (2D) model without an external field, and in this study, we further extend these successes to the 3D model, which has a far more complicated energy landscape than the 2D one. In particular, we provide a detailed description of the highly complex plateau structure of saddle configurations between ground states and then analyze the typical behavior of the Glauber dynamics thereon. Thus, we acheive a quantitatively precise analysis of metastability, including the Eyring-Kramers law, the Markov chain model reduction, and a full characterization of metastable transition paths.