Uniform magnetic excitation in antiferromagnetic MnN

Antiferromagnets are considered to be promising materials for future spintronic devices; the simulation and theoretical analysis are important to improve our understanding of the dynamics of antiferromagnetic materials, as relevant experiments are less convenient compared with ferromagnets. MnN is a collinear antiferromagnet noted for its large anisotropy, high N\'eel temperature, and potential for electrical switching in antiferromagnetic spintronics. In this work, the antiferromagnetic resonance of collinear MnN has been theoretically calculated using the macrospin model. The obtained results are then compared with our simulation performed at the natural atomic order of antiferromagnets, using parameters taken from reported first-principles calculations and experiments. The frequency-field dependence and chirality characteristics of all modes in antiferromagnetic resonance in the case of different external fields applied parallel or perpendicular to the easy axis are investigated in detail. The analytical results derived from the macrospin model show good agreement with the simulated data. In addition, the static magnetic properties of MnN obtained from atomistic simulation closely match the reported experimental or our analytical results. This work helps to understand the dynamics of collinear antiferromagnetic materials.