Spin dynamics simulations on the Surface of a nanoscale Heisenberg antiferromagnet*

Monte Carlo and spin dynamics techniques with fourth-order Suzuki-Trotter decompositions of the exponential operator have been used to perform large-scale simulations of the dynamic behavior of a nanoscale, classical, Heisenberg antiferromagnet on a simple cubic lattice at a temperature below the Nèel temperature 1 . A classical isotropic Heisenberg model with an antiferromagnetic nearest-neighbor exchange interaction was studied. A simple cubic lattice with free boundary conditions was used. The assumption of q-space spin-wave reflections with broken momentum conservation due to free-surface confinements was developed and used to explain multiple excitation peaks for wave vectors within the first Brillouin zone that appear in the spin-wave spectra of the transverse component of dynamic structure factor S^T(q, ω) in the nanoscale classical Heisenberg antiferromagnet. In this study, we applied the same simulation techniques to the nanoscale classical Heisenberg antiferromagnet we studied before for studying spin dynamic behavior on the surfaces of a nanoscale antiferromagnet.

1 Z.Hou, D. P. Landau, G. M. Stocks, and G. Brown, Phys.Rev.B 91, 064417(2015)