Transverse Spin-Gradient Functional for Noncollinear Spin-Density-Functional Theory
Transverse Spin-Gradient Functional for Noncollinear Spin-Density-Functional Theory
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DOI：
10.1103/physrevlett.111.156401
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发表时间：
2013-10-08
影响因子：
8.6
通讯作者：
Gross, E. K. U.
中科院分区：
文献类型：
--
作者：
Eich, F. G.;Gross, E. K. U.
我们提出了一种新的自旋密度泛函理论，旨在描述非共线磁结构。泛函的构造采用均匀电子气的自旋螺旋波态作为参考系。我们证明该函数取决于自旋磁化强度的横向梯度；即，与广泛使用的局部自旋密度近似相反，泛函对自旋磁化方向的局部变化敏感。因此，交换相关磁场与自旋磁化强度不平行，并且 Kohn-Sham 系统的基态中存在局部自旋扭矩。作为原理证明，我们将泛函应用于非共线 120 度尼尔态的铬单层。
We present a novel functional for spin-density-functional theory aiming at the description of noncollinear magnetic structures. The construction of the functional employs the spin-spiral-wave state of the uniform electron gas as reference system. We show that the functional depends on transverse gradients of the spin magnetization; i.e., in contrast with the widely used local spin density approximation, the functional is sensitive to local changes of the direction of the spin magnetization. As a consequence the exchange-correlation magnetic field is not parallel to the spin magnetization and a local spin torque is present in the ground state of the Kohn-Sham system. As a proof of principle, we apply the functional to a Chromium monolayer in the noncollinear 120 degrees-Neel state.