A New Magnetic Topological Quantum Material Candidate by Design
A New Magnetic Topological Quantum Material Candidate by Design
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DOI：
10.1021/acscentsci.9b00202
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发表时间：
2019-05-22
影响因子：
18.2
通讯作者：
Cava, Robert J.
中科院分区：
文献类型：
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作者：
Gui, Xin;Pletikosic, Ivo;Cava, Robert J.
当磁性与非常规的电子能带结构结合时，可以产生前沿的电子性质，例如量子反常霍尔效应，轴子电动力学和马约拉纳费米子。在这里，我们报告了EuSn 2 P2的高质量晶体的表征，EuSn 2 P2是一种专门设计用于产生非常规电子态和磁性的新量子材料。EuSn 2 P2具有层状Bi 2 Te 3型结构。铁磁相互作用主导Curie-Weiss磁化率，但在30 K附近发生向反铁磁有序的转变。中子衍射表明，这是由于二维铁磁自旋排列在个别Eu层和层之间的反铁磁排列-这种磁性状态包围在低温下的Sn-P层。体电阻率对磁性很敏感。电子结构计算表明，EuSn 2 P2是一种强拓扑绝缘体，有望成为一种新型的磁性拓扑量子材料。计算表明，表面状态应该存在，他们确实观察到的角度分辨光电子能谱（ARPES）测量。
Magnetism, when combined with an unconventional electronic band structure, can give rise to forefront electronic properties such as the quantum anomalous Hall effect, axion electrodynamics, and Majorana fermions. Here we report the characterization of high-quality crystals of EuSn2P2, a new quantum material specifically designed to engender unconventional electronic states plus magnetism. EuSn2P2 has a layered, Bi2Te3-type structure. Ferromagnetic interactions dominate the Curie-Weiss susceptibility, but a transition to antiferromagnetic ordering occurs near 30 K. Neutron diffraction reveals that this is due to two-dimensional ferromagnetic spin alignment within individual Eu layers and antiferromagnetic alignment between layers-this magnetic state surrounds the Sn-P layers at low temperatures. The bulk electrical resistivity is sensitive to the magnetism. Electronic structure calculations reveal that EuSn2P2 might be a strong topological insulator, which can be a new magnetic topological quantum material (MTQM) candidate. The calculations show that surface states should be present, and they are indeed observed by angle-resolved photoelectron spectroscopy (ARPES) measurements.