Effects of magnetic anisotropy on spin and thermal transport in classical antiferromagnets on the square lattice

Transport properties of the classical antiferromagnetic XXZ model on the square lattice have been theoretically investigated, putting emphasis on how the occurrence of a phase transition is reflected in spin and thermal transports. As is well known, the anisotropy of the exchange interaction Δ≡Jz/Jx plays a role to control the universality class of the transition of the model, i.e., either a second-order transition at TN into a magnetically ordered state or the Kosterlitz-Thouless (KT) transition at TKT, which respectively occur for the Ising-type (Δ>1) and XY-type (Δ