论文标题
拓扑Weyl和节点环在铁磁和铁磁性双perovskites中的共存
Coexistence of topological Weyl and nodal-ring states in ferromagnetic and ferrimagnetic double perovskites
论文作者
论文摘要
磁性拓扑量材料由于晶体学，磁性和拓扑之间的相互作用引起的外来拓扑量子物理学引起了极大的关注，这对于基础研究和技术应用至关重要。但是，有限的材料是实验可用的，其中大多数是通过磁杂质掺杂或异质结构构造实现的。在这项工作中，基于第一原理计算，我们预测双钙钛矿BA2CDREO6是一种固有的铁磁拓扑半倾斜度半半米，而铁磁性双perovskite与太空集团对称性fm-3m，例如Ba2femoo6，例如Ba2femoo6，例如Ba2femoo6，属于拓扑半微米。在BA2CDREO6的费米水平附近发现了一对Weyl点和完全自旋的节点环状态。它的二维几乎平坦的鼓头表面状态完全自旋偏振。然而，在BA2FEMOO6中，在费米水平附近存在四对Weyl点和两个完全自旋的节点环。在存在自旋轨道耦合的情况下，这些拓扑特性是稳定的。这使得这些材料成为研究新出现的有趣特性的合适平台，尤其是用于旋转技术，信息技术和拓扑超导性的应用。
Magnetic topological quantum materials have attracted great attention due to their exotic topological quantum physics induced by the interplay among crystalology, magnetism, and topology, which is of profound importance to fundamental research and technology applications. However, limited materials are experimentally available, most of whom are realized by magnetic impurity doping or heterostructural constructions. In this work, based on the first-principles calculations, we predict that double perovskite Ba2CdReO6 is an intrinsic ferromagnetic topological semi-half-metal, while the ferrimagnetic double perovskite with space group symmetry Fm-3m, such as Ba2FeMoO6, belongs to a topological half-metal. One pair of Weyl points and fully spin-polarized nodal-ring states are found in the vicinity of the Fermi level in Ba2CdReO6. Its two-dimensional nearly flat drumhead surface states are fully spin-polarized. In Ba2FeMoO6, however, there exist four pairs of Weyl points and two fully spin-polarized nodal-rings near the Fermi level. These topological properties are stable in the presence of spin-orbit coupling. This makes these materials be an appropriate platform for studying the emerging intriguing properties, especially for the applications in spintronics, information technology, and topological superconductivity.
