Lattice-compliant simulations of antiferromagnetic textures and their response to spin-orbit torques

Spin textures in perfectly ordered antiferromagnetic ultrathin films are evaluated on the basis of atomistic simulations and compared to the results of recent extensions of the (l, m) decomposition model. A comparison between similar textures supported by either a bcc or a fcc lattice shows that the sole inclusion of symmetric Heisenberg exchange interactions suffices to provide, when geometry commands, a natural canting between neighboring s up arrow and s down arrow spins within a texture. Moreover, a pure "at lattice points" dipole model leads to natural symmetries, in clear disagreement with expectations from the (l, m) model. Inversely, properties such as wall mobility under spin-orbit torques depending mostly on wall geometrical characteristics such as chirality and chirality axis orientation prove, as anticipated, primarily lattice immune.