Evolution of possible Weyl semimetal states across the Mott transition in pyrochlore iridates induced by hole doping
Evolution of possible Weyl semimetal states across the Mott transition in pyrochlore iridates induced by hole doping
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空穴掺杂引起的烧绿石铱酸盐中莫特转变过程中可能的韦尔半金属态的演化
DOI：
10.1103/physrevb.102.245131
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发表时间：
2020
影响因子：
3.7
通讯作者：
and Y. Tokura
中科院分区：
文献类型：
--
作者：
K. Ueda;H. Fukuda;R. Kaneko;J. Fujioka;and Y. Tokura
我们通过研究烧绿石（表示稀土离子）的磁输运特性，选择三种类型的离子来设计Irmoments之间的交换耦合方案：非磁性Eu、各向同性Gd和各向异性Tb，研究强相关电子的可能的Weyl半金属。在掺杂诱导的半金属态下，由于交换增强各向同性和各向异性塞曼场的影响，在Tb化合物和Tb化合物中分别观察到了磁阻和霍尔效应的独特特征，这体现了理论预测的双Weyl半金属和二进二出线节点半金属。特别是，化合物的霍尔角大幅增强至 1.5%，略高于莫特跃迁的临界掺杂。此外，对于化合物的较低掺杂制度，可以看出非常规霍尔贡献，这可以归因于具有场扭曲全进全出有序态的韦尔点的出现。这些发现表明，空穴掺杂引起的莫特转变以及特征交换相互作用可以在广泛的材料参数空间中稳定多种拓扑半金属态。
We study possible Weyl semimetals of strongly correlated electrons by investigating magnetotransport properties in pyrochlore(denotes rare-earth ions), choosing three types ofions to design the exchange coupling scheme betweenand Irmoments: nonmagnetic Eu, isotropic Gd, and anisotropic Tb. In the doping-induced semimetallic state, distinctive features of magnetoresistance and the Hall effect are observed inand Tb compounds due to the effects of the exchange-enhanced isotropic and anisotropic Zeeman fields, respectively, exemplifying the double-Weyl semimetal and the two-in two-out line-node semimetal as predicted by theories. In particular, the Hall angle of ancompound is strongly enhanced to 1.5% just above the critical doping for the Mott transition. Furthermore, an unconventional Hall contribution is discerned for a lower doping regime of thecompound, which can be ascribed to the emergence of Weyl points with the field-distorted all-in all-out order state. These findings indicate that the hole-doping-induced Mott transition as well as the characteristicexchange interaction stabilizes versatile topological semimetal states in a wide range of material parameter space.