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...

We show that a partial ordering appears in the limit S → ∞ at the ground state of the 1D spin-S antiferromagnetic Ising model with next-nearest-neighbour interaction. This is an analogue of the ordering which appears at finite S = Sc ≈ 3 in the nearest-neighbour Ising antiferromagnet on...