用半局域泛函捕获交换关联自旋扭矩效应
Capturing exchange-correlation spin-torque effects with a semilocal functional
AI总结：
通过自旋流密度泛函理论（SCDFT）框架，在半局域泛函中引入交换关联自旋扭矩，实现首个U(1)×SU(2)规范不变的SCDFT泛函，应用于Cr3分子和MnO体相，发现与精确交换方法同量级的自旋扭矩及反直觉能量贡献。
摘要：
我们通过自旋流密度泛函理论（SCDFT）框架处理交换关联（XC）效应，弥补了半局域XC泛函中缺乏XC自旋扭矩的问题，并在维也纳从头算模拟包（VASP）中实现了这类新型XC泛函家族的首个泛函：一个U(1)×SU(2)规范不变的SCDFT泛函，具有$2\ imes 2$ XC势。虽然该框架可应用于其他XC泛函，但本文展示的SCDFT泛函基于Becke-Roussel交换和Colle-Salvetti关联。除了$2\ imes 2$自旋密度和动能密度，该XC泛函还依赖于$2\ imes 2$自旋流密度。实现需要在投影缀加波方法中计算自旋流密度，以及XC能量对其的变分。应用于Cr$_3$分子和体相MnO的结果表明：（i）XC自旋扭矩与包含精确交换的方法得到的量级相同；（ii）即使在无自旋轨道耦合的共线铁磁系统中，由于磁化的半局域性，对能量存在反直觉的贡献；（iii）每个电子步的计算成本与依赖于动能密度等的计算相当，但收敛所需的电子步数更少。
英文摘要：
We cure the lack of exchange-correlation (XC) spin torque in semilocal XC functionals by treating XC effects in the framework of spin-current-density-functional theory (SCDFT), and present the implementation of the first kind of this novel family of XC functionals in the Vienna ab-initio simulation package (VASP): An U(1)$\times$SU(2) gauge-invariant SCDFT functional featuring a $2\times 2$ XC potential. While the framework can be applied to other XC functionals, the presented flavor of the SCDFT functional is based on Becke-Roussel exchange and Colle-Salvetti correlation. In addition to the $2\times 2$ spin density and kinetic-energy density, the XC functional depends on the $2\times 2$ spin-current density. The implementation requires the computation of the spin-current density within the projector-augmented-wave method and the variation of the XC energy with respect to it. The application to a Cr$_3$ molecule and bulk MnO reveals (i) XC spin torque of the same order as obtained by methods including exact exchange, (ii) a counterintuitive contribution to the energy even in collinear ferromagnetic systems without spin-orbit coupling due to the semilocality of the magnetization, and (iii) a similar computational cost per electronic step as calculations that depend on, inter alia, the kinetic-energy density, but convergence within fewer electronic steps.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
