论文标题
磁缺陷的作用和磁性拓扑绝缘子的缺陷工程
Role of Magnetic Defects and Defect-engineering of Magnetic Topological Insulators
论文作者
论文摘要
磁缺陷在磁性拓扑绝缘子（TIS）中起着重要但知之甚少的作用。例如，拓扑表面传输和散装磁性特性受BI $ _2 $ SE $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _2 $ _2 $ _2 $ _4 $ _4 $（MBT）基于抗Fiferromagnetic（Afm）TIS的磁性缺陷控制。尽管具有新生的铁磁性，但我们的非弹性中子散射数据表明，SB $ _2 $ _2 $ _3 $中的MN缺陷的一部分形成了五重奏块中强的AFM Dimer Singlets。 AFM superexchange耦合通过MN-TE-MN线性键进行，并且与MBT中的AFM耦合与AFM耦合相同，并在两种材料类中建立了共同的相互作用。我们还发现（SB $ _ {1-X} $ Mn $ _X $）$ _ 2 $ TE $ _3 $中的FM相关性很可能是由跨范德华瓦斯缝隙中相邻的五重奏块中的磁性缺陷驱动的。除了提供有关稀释Ti中FM顺序演变的长期问题的答案外，这些结果还表明，在SB拟合的MBT中，全球磁顺序从AFM到FM的演变受InterableOck和Interblock Interblock耦合的缺陷工程的控制。
Magnetic defects play an important, but poorly understood, role in magnetic topological insulators (TIs). For example, topological surface transport and bulk magnetic properties are controlled by magnetic defects in Bi$_2$Se$_3$-based dilute ferromagnetic (FM) TIs and MnBi$_2$Te$_4$ (MBT)-based antiferromagnetic (AFM) TIs. Despite its nascent ferromagnetism, our inelastic neutron scattering data show that a fraction of the Mn defects in Sb$_2$Te$_3$ form strong AFM dimer singlets within a quintuple block. The AFM superexchange coupling occurs via Mn-Te-Mn linear bonds and is identical to the AFM coupling between antisite defects and the FM Mn layer in MBT, establishing common interactions in the two materials classes. We also find that the FM correlations in (Sb$_{1-x}$Mn$_x$)$_2$Te$_3$ are likely driven by magnetic defects in adjacent quintuple blocks across the van der Waals gap. In addition to providing answers to long-standing questions about the evolution of FM order in dilute TI, these results also show that the evolution of global magnetic order from AFM to FM in Sb-substituted MBT is controlled by defect engineering of the intrablock and interblock coupling.
