论文标题
铁和镍中的交换相互作用：DFT+DMFT研究
Exchange interactions in iron and nickel: DFT+DMFT study in paramagnetic phase
论文作者
论文摘要
我们分析了在磁磁相中的密度功能理论以及动态平均场理论（DFT+DMFT）方法中计算磁交换相互作用的可能方法。使用在梯形DMFT方法中获得的敏感性以及海森堡模型的随机相位近似结果，我们获得了双线交换相互作用。我们表明，Stepanov等人较早获得的结果。 [物理。莱特牧师。 121，037204（2018）;物理。 Rev. B 105，155151（2022）]对应于在非本地相关性中考虑每个轨道中每个轨道中的单个磁矩。我们考虑一种更通用的方法，并将其应用于评估铁和镍的有效磁参数。我们表明，基于轨道染色的反向敏感性，该分析为弱磁体和强磁体带来了合理的结果。对于铁，我们发现，在低温限制中，交换交互$ j_0 \ simeq 0.20 $ eV，而对于镍，我们获得了$ j_0 \ simeq 1.2 $ ev。考虑的方法还允许人们在温度下描述自旋波散$ t \ sim t_c $，这与实验数据一致。
We analyze possible ways to calculate magnetic exchange interactions within the density functional theory plus dynamical mean-field theory (DFT+DMFT) approach in the paramagnetic phase. Using the susceptibilities obtained within the ladder DMFT approach together with the random phase approximation result for the Heisenberg model, we obtain bilinear exchange interactions. We show that the earlier obtained result of Stepanov et al. [Phys. Rev. Lett. 121, 037204 (2018); Phys. Rev. B 105, 155151 (2022)] corresponds to considering individual magnetic moments in each orbital in the leading-order approximation in the non-local correlations. We consider a more general approach and apply it to evaluate the effective magnetic parameters of iron and nickel. We show that the analysis, based on the inverse orbital-summed susceptibilities, yields reasonable results for both, weak and strong magnets. For iron we find, in the low-temperature limit, the exchange interaction $J_0\simeq 0.20$ eV, while for nickel we obtain $J_0\simeq 1.2$ eV. The considered method also allows one to describe the spin-wave dispersion at temperatures $T\sim T_C$, which is in agreement with the experimental data.
