Yttrium iron garnet is a complex ferrimagnetic insulator with 20 magnon modes which is used extensively in fundamental experimental studies of magnetisation dynamics. As a transition metal oxide with moderate gap (2.8eV), yttrium iron garnet requires a careful treatment of electronic correlation. We have applied quasiparticle self-consistent GW to provide a fully ab initio description of the electronic structure and resulting magnetic properties, including the parameterisation of a Heisenberg model for magnetic exchange interactions. Subsequent spin dynamical modelling with quantum statistics extends our description to the magnon spectrum and thermodynamic properties such as the Curie temperature, finding favourable agreement with experimental measurements. This work provides a snapshot of the state-of-the art in modelling of complex magnetic insulators.

钇铁石榴石是一种复杂的亚铁磁绝缘体，具有 20 个磁振子模式，广泛用于磁化动力学的基础实验研究。作为具有中等间隙 (2.8eV) 的过渡金属氧化物，钇铁石榴石需要仔细处理电子相关性。我们已经应用准粒子自洽 GW 来提供一个完全从头电子结构和由此产生的磁特性的描述，包括用于磁交换相互作用的海森堡模型的参数化。随后使用量子统计的自旋动力学建模将我们的描述扩展到磁振子光谱和热力学特性，例如居里温度，与实验测量结果一致。这项工作提供了对复杂磁绝缘体建模的最新技术的快照。