Antiferromagnetic Ising model
= Antiferromagnetic Ising model
{title2=$J>0$}
With the convention $H=J\sum_{\langle ij\rangle}\sigma_i\sigma_j-h\sum_i\sigma_i$, positive $J$ favors opposite neighboring <Ising spins>. On a <bipartite graph>, the <Néel order parameter> measures opposite sublattice <magnetizations>; it is distinct from the uniform <magnetization>. Changing the signs of spins on one sublattice maps the zero-field model to the ferromagnetic <Ising model>.