Physical review. B, Condensed matter
Phase diagram of the Ising model on the square lattice with crossed diagonal bonds
A. Nihat Berker, Kenneth Hui
Abstract
The global phase diagram of the spin-1/2 Ising model with nearest- and next-nearest-neighbor interactions on the square lattice is considered, including the fully anisotropic cases. A closed-form expression is given that accurately represents the phase boundaries when the crossed next-nearest-neighbor interactions are not of opposite signs. The phase diagram includes disordered, ferromagnetic, antiferromagnetic, axially single-striped, and diagonally double-striped phases.