Mankovsky Sergiy, Polesya Svitlana, Lange Hannah, Weißenhofer Markus, Nowak Ulrich, Ebert Hubert
Department of Chemistry/Physical Chemistry, LMU Munich, Butenandtstrasse 11, D-81377 Munich, Germany.
Department of Physics, University of Konstanz, DE-78457 Konstanz, Germany.
Phys Rev Lett. 2022 Aug 5;129(6):067202. doi: 10.1103/PhysRevLett.129.067202.
The transfer and control of angular momentum is a key aspect for spintronic applications. Only recently, it was shown that it is possible to transfer angular momentum from the spin system to the lattice on ultrashort timescales. To contribute to the understanding of angular momentum transfer between spin and lattice degrees of freedom we present a scheme to calculate fully relativistic spin-lattice coupling parameters from first principles. In addition to the dipole-dipole interactions often discussed in the literature, these parameters give, in particular, access to the spin-lattice effects controlled by spin-orbit coupling. By treating changes in the spin configuration and atomic positions at the same level, closed expressions for the atomic spin-lattice coupling parameters can be derived in a coherent manner up to any order. Analyzing the properties of these parameters, in particular their dependence on spin-orbit coupling, we find that even in bcc Fe the leading term for the angular momentum exchange between the spin system and the lattice is a Dzyaloshiskii-Moriya-type interaction, which is due to the symmetry breaking distortion of the lattice.
角动量的转移与控制是自旋电子学应用的一个关键方面。直到最近，才有人表明在超短时间尺度上可以将角动量从自旋系统转移到晶格。为了有助于理解自旋与晶格自由度之间的角动量转移，我们提出了一种从第一性原理计算完全相对论性自旋 - 晶格耦合参数的方案。除了文献中经常讨论的偶极 - 偶极相互作用外，这些参数尤其能够获取由自旋 - 轨道耦合控制的自旋 - 晶格效应。通过在同一层面处理自旋构型和原子位置的变化，可以连贯地推导出直至任意阶的原子自旋 - 晶格耦合参数的封闭表达式。分析这些参数的性质，特别是它们对自旋 - 轨道耦合的依赖性，我们发现即使在体心立方铁中，自旋系统与晶格之间角动量交换的主导项也是一种Dzyaloshiskii - Moriya型相互作用，这是由于晶格的对称性破缺畸变所致。
