SPT extension of $Z_2$ quantum Ising model's ferromagnetic phase

This paper focuses on the creation of a model with explicitly defined symmetry-protected topological (SPT) phases on a triangular lattice as an extension of $Z_2$ Ising model's ferromagnetic phase. Unlike in previously known similar works, this model is based on an initially interacting system which is known to describe experimentally realizable physical systems. The Hamiltonian for these edge states contains four-point spin interactions between next-to-next nearest neighbors. As an initially interacting A generic technique for creating SPT models is developed, allowing for the construction of translation-invariant edge models.