Exact solution of an anisotropic centered honeycomb Ising lattice: Reentrance and partial disorder

Abstract
The exact phase diagram of an anisotropic centered honeycomb Ising lattice is obtained by transforming the system into a 32-vertex model that satisfies the free-fermion condition. We show that for a range of interaction parameters, a paramagnetic reentrant phase exists on the temperature scale between two ordered phases. The high-temperature ordered phase possesses partial disorder, in agreement with theoretical conjecture.