论文标题
压力诱导的理想WEYL半准状态在分层的抗fiferromagnet EUCD2AS2中
Pressure-induced ideal Weyl semimetal state in the layered antiferromagnet EuCd2As2
论文作者
论文摘要
在分层的抗铁磁铁EUCD2AS2中植根于磁性与拓扑之间的相互作用的丰富的非平凡拓扑阶段已引起了广泛的关注,尤其是在自旋极偏置的铁磁(FM)结构中实现的理想的Weyl Semimetal状态,由中等外部磁场驱动。在这项工作中,结合高压磁铁运动测量,结构性化合物和第一原理计算,我们发现压力的应用还可以通过驱动平面内抗磁性状态的eucd2as2中理想的WEYL状态,然后跨越平面内FM状态,然后进入室外fm范围内。我们的高压角度色散X射线衍射和X射线吸收近边光谱测量结果排除了EU2+价状态的结构转变和/或变化,作为磁相跃迁的来源。或者,明显降低的轴向比(C/A)和压缩的欧盟层空间距离应扮演重要角色。我们的结果提供了一种替代方法来实现EUCD2AS2中理想的Weyl半学状态,并且将在这种分层的磁性拓扑阶段探索外来拓扑特性,并使用高压通过高压进行了强烈竞争的磁性交换。
The rich nontrivial topological phases rooted in the interplay between magnetism and topology in the layered antiferromagnet EuCd2As2 have captured vast attention, especially the ideal Weyl semimetal state realized in the spin-polarized ferromagnetic (FM) structure driven by a moderate external magnetic field. In this work, combining high-pressure magnetotransport measurements, structure chracterizations and first principles calculations, we find that application of pressure can also realize the ideal Weyl state in EuCd2As2 through driving the in-plane antiferromagnetic state across an intermediate in-plane FM state then into the out-of-plane FM state. Our high-pressure angle dispersive X-ray diffraction and X-ray absorption near-edge spectroscopy measurements excluded structure transition and/or change of Eu2+ valence state as the sources for the magnetic phase transitions. Alternatively, the apparently reduced axial ratio (c/a) and compressed Eu-layer space distance should play important roles. Our result provides an alternative way to realize the ideal Weyl semimetal state in EuCd2As2 and would be instructive for the exploration of exotic topological properties in such layered magnetic topological phase with strongly competing magnetic exchanges by using high pressure.