论文标题
对分层磁和极性狄拉克金属的高场研究
High-field Studies on Layered Magnetic and Polar Dirac Metals
论文作者
论文摘要
最近，由于发现了非常规的运输和光学现象，因此Dirac/Weyl fermion和各种体积特性（例如磁性）之间的相互作用引起了极大的关注。但是，此类材料的设计原理尚未确定。在这里，我们提出，分层材料$ a $ a $ x_2 $（$ a $：碱性和稀土离子，$ x $：sb，bi）是一个有前途的平台，用于系统地探索密切相关的迪拉克金属，由$ x^ - $ x^ - $ x-$ x-$ x-$ square net the 2d dirac fermion and the 2d dirac fermion and the 2d dirac fermion和the 2d dirac fermion和$ a^{2+} $ - mn $^{2+} $ - $ x^{3 - } $磁性块层。在本文中，我们将回顾有关此系列材料的最新高场研究，以证明通过设计块层实现了各种类型的Dirac费米子。首先，我们概述了Dirac Fermion，并在Eumnbi $ _2 $（$ a $ = eu）中的磁性顺序。该材料通过田间诱导的欧盟层磁性变化表现出很大的磁化，这与Dirac Fermion和本地欧盟时刻之间的强交换相互作用有关。其次，我们审查了Dirac Fermion，以及BAMN $ x_2 $（$ a $ = ba）的晶格极化。在那里，自旋谷耦合由于Zeeman型自旋轨道相互作用而表现出来，这在实验中通过在高场上观察到的散装量子霍尔效应在实验上证明了这一点。
Recently, the interplay between the Dirac/Weyl fermion and various bulk properties, such as magnetism, has attracted considerable attention, since unconventional transport and optical phenomena were discovered. However, the design principles for such materials have not been established well. Here, we propose that the layered material $A$Mn$X_2$ ($A$: alkaline and rare-earth ions, $X$: Sb, Bi) is a promising platform for systematically exploring strongly correlated Dirac metals, which consists of the alternative stack of the $X^-$ square net layer hosting a 2D Dirac fermion and the $A^{2+}$-Mn$^{2+}$-$X^{3-}$ magnetic block layer. In this article, we shall review recent high-field studies on this series of materials to demonstrate that various types of Dirac fermions are realized by designing the block layer. First, we give an overview of the Dirac fermion coupled with the magnetic order in EuMnBi$_2$ ($A$=Eu). This material exhibits large magnetoresistance by the field-induced change in the magnetic order of Eu layers, which is associated with the strong exchange interaction between the Dirac fermion and the local Eu moment. Second, we review the Dirac fermion coupled with the lattice polarization in BaMn$X_2$ ($A$=Ba). There, spin-valley coupling manifests itself owing to the Zeeman-type spin-orbit interaction, which is experimentally evidenced by the bulk quantum Hall effect observed at high fields.
