We present a spin-32 Ising model which is equivalent to a “two-layer” Ising model. We find a solvable spin-32 Ising model and show that a system may have several critical exponents η corresponding to correlation functions of different Ising-type variables. We find two phase-transition...

We investigate an Ising model with three-spin interactions and five-spin interactions on a square lattice. We use exact mapping relations among interaction parameters and the temperature. We found that the system is equivalent to the eight-vertex model in some cases. For the system with an...

A mixed spin-12 and spin-1 transverse Ising model with two- and four-spin interactions and crystal field on the honeycomb lattice is studied using a generalized mapping transformation technique. Exact expressions for the critical temperature, the magnetization, the correlation functions, the...

A mixed spin-12 and spin-S transverse Ising model with two- and four-spin interactions on the honeycomb lattice is studied using a generalized mapping transformation technique. The exact expressions for the critical temperature, the magnetization, the correlation functions, the internal energy...