论文标题
$ j = 3/2 $ quasiparticles介导的各向异性rkky互动中的半身拓扑半学
Anisotropic RKKY interactions mediated by $j=3/2$ quasiparticles in half-Heusler topological semimetal
论文作者
论文摘要
从理论上讲，我们探讨了由旋转3/2准粒子在准二维几何形状中的半螺旋拓扑半学中介导的rkky相互作用。我们发现，虽然Kohn-Luttinger术语引起了$ {\ cal H} _ {\ rm rkky} \ proptσ_{1，i} {\ cal i} _ {ij} _ {ij}σ_{2，j {2，j {2，j} $ cal cal cat i} _ {ij} $，添加小的反对称线性旋转式轨耦合术语导致dzyaloshinskii-moriya（dm）与反对称矩阵$ {\ cal i}'_ _ _ {ij} $。我们证明，除了对距离的振荡依赖性外，所有耦合强度都在很大程度上取决于两个杂质相对于晶格的相对取向。对于$ {\ cal i} _ {ij} $，这产生了强烈的各向异性行为，这样只要在恒定距离绕另一个杂质旋转另一个杂质，我们就可以看到Rkky耦合的进一步振荡。这种前所未有的效果是我们系统独有的，它将旋转轨道耦合与强烈各向异性的费米表面相结合。我们进一步发现，所有rkky术语都有两个共同的特征：空间变化图中的四方翘曲以及复杂的跳动模式。有趣的是，所有这些特征都可以在所有兴奋剂中存活，并且我们在电子和孔掺杂的情况下都能看到它们。此外，由于尺寸较低以及不同的自旋轨耦合的效果，我们看到，只有一个对称的偏置术语，$ {\ cal i} _ {xy} $和两个dm零件$ {\ cal i}非对角线组件相同。与具有SPIN-1/2有效描述的电子系统相比，这表明了Half-Heusler拓扑半学的Rkky相互作用的另一个急剧差异。
We theoretically explore the RKKY interaction mediated by spin-3/2 quasiparticles in half-Heusler topological semimetals in quasi-two-dimensional geometries. We find that while the Kohn-Luttinger terms gives rise to generalized Heisenberg coupling of the form ${\cal H}_{\rm RKKY} \propto σ_{1,i} {\cal I}_{ij} σ_{2,j}$ with a symmetric matrix ${\cal I}_{ij}$, addition of small antisymmetric linear spin-orbit coupling term leads to Dzyaloshinskii-Moriya (DM) coupling with an antisymmetric matrix ${\cal I}'_{ij}$. We demonstrate that besides the oscillatory dependence on the distance, all coupling strengths strongly depend on the relative orientation of the two impurities with respect to the lattice. This yields a strongly anisotropic behavior for ${\cal I}_{ij}$ such that by only rotating one impurity around another at a constant distance, we can see further oscillations of the RKKY couplings. This unprecedented effect is unique to our system which combines spin-orbit coupling with strongly anisotropic Fermi surfaces. We further find that all of the RKKY terms have two common features: a tetragonal warping in their map of spatial variations, and a complex beating pattern. Intriguingly, all these features survive in all dopings and we see them in both electron- and hole-doped cases. In addition, due to the lower dimensionality combined with the effects of different spin-orbit couplings, we see that only one symmetric off-diagonal term, ${\cal I}_{xy}$ and two DM components ${\cal I}'_{xz}$ and ${\cal I}'_{yz}$ are nonvanishing, while the remaining three off-diagonal components are identically zero. This manifests another drastic difference of RKKY interaction in half-Heusler topological semimetals compared to the electronic systems with spin-1/2 effective description.
