论文标题
用于磁交换常数的磁力定理的平面波实施：应用于大量Fe，Co和Ni
Plane wave implementation of the magnetic force theorem for magnetic exchange constants: Application to bulk Fe, Co and Ni
论文作者
论文摘要
我们提出了磁力定理的平面波实施，该实现提供了一个第一原理框架，用于提取交换常数参数化磁性材料的经典Heisenberg模型描述。结果表明，全显微镜交换张量可以用静态的kohn-sham敏感性张量和交换相关磁场表示。该公式允许人们定义局部定义为预定义空间区域的任意磁位点，从而使发现Heisenberg参数的问题与问题的任何轨道分解无关。易感性是在平面波基础上计算的，这允许相对于无占用带和空间表示的系统收敛。然后，我们将该方法应用于研究批量FE，CO和NI的绝热旋转波谱的充分研究的问题，与先前的计算找到了良好的一致性。特别是，我们利用定义磁位点的自由来表明，计算出的海森堡参数对磁性位点的定义变化具有鲁棒性。这表明磁位点可以被视为明确的定义，因此尽管磁性的静态性质，但仍断言了海森堡模型描述的相关性。
We present a plane wave implementation of the magnetic force theorem, which provides a first principles framework for extracting exchange constants parameterizing a classical Heisenberg model description of magnetic materials. It is shown that the full microscopic exchange tensor may be expressed in terms of the static Kohn-Sham susceptibility tensor and the exchange-correlation magnetic field. This formulation allows one to define arbitrary magnetic sites localized to predefined spatial regions, hence rendering the problem of finding Heisenberg parameters independent of any orbital decomposition of the problem. The susceptibility is calculated in a plane wave basis, which allows for systematic convergence with respect to unoccupied bands and spatial representation. We then apply the method to the well-studied problem of calculating adiabatic spin wave spectra for bulk Fe, Co and Ni, finding good agreement with previous calculations. In particular, we utilize the freedom of defining magnetic sites to show that the calculated Heisenberg parameters are robust towards changes in the definition of magnetic sites. This demonstrates that the magnetic sites can be regarded as well-defined and thus asserts the relevance of the Heisenberg model description despite the itinerant nature of the magnetic state.
