arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.05840cond-mat.mtrl-sci
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磁性拓扑范德华异质结构的设计

Designing Magnetic Topological van der Waals Heterostructure

Anh Pham, Panchapakesan Ganesh

摘要:

提出了一种利用二维磁体CrI $_3$和二维材料Ge/Sb相结合的vdw异质结构(vdw-HS)设计二维功能磁性拓扑异质结构(HS)的新方法,实现了具有非零Chern数(C=1)和手征边缘态的新的二维拓扑系统。非平凡的拓扑结构主要源自于CrI $_3$层,而非磁性元素诱导电荷转移过程和邻近增强的自旋轨道耦合。由于这些独特的属性,我们的拓扑磁性vdw-HS克服了弱磁化通过邻近效应在以前的设计,因为磁化和拓扑共存于同一个磁性层。具体地说,我们的双层CrI $_3$ /Sb和三层CrI $_3$ /Sb/CrI $_3$系统表现出不同的拓扑基态,从反铁磁拓扑晶体绝缘体(C $_M$ = 2)到QAHE。这些非平凡的拓扑转变被证明是可切换的三层结构中,由于从反铁磁性的铁磁性的存在下,一个外部的垂直电场的值小至0.05 eV/A的磁开关。因此,我们的研究提出了一个现实的系统,设计可切换的磁拓扑器件与电场。

英文摘要:

We demonstrate a new method of designing 2D functional magnetic topological heterostructure (HS) by exploiting the vdw heterostructure (vdw-HS) through combining 2D magnet CrI$_3$ and 2D materials (Ge/Sb) to realize new 2D topological system with nonzero Chern number (C=1) and chiral edge state. The nontrivial topology originates primarily from the CrI$_3$ layer while the non-magnetic element induces the charge transfer process and proximity enhanced spin-orbit coupling. Due to these unique properties, our topological magnetic vdw-HS overcomes the weak magnetization via proximity effect in previous designs since the magnetization and topology coexist in the same magnetic layer. Specifically, our systems of bilayer CrI$_3$/Sb and trilayer CrI$_3$/Sb/CrI$_3$ exhibit different topological ground state ranging from antiferromagnetic topological crystalline insulator (C$_M$= 2) to a QAHE. These nontrivial topological transition is shown to be switchable in a trilayer configuration due to the magnetic switching from antiferromagnetism to ferromangetism in the presence an external perpendicular electric field with value as small as 0.05 eV/A. Thus our study proposes a realistic system to design switchable magnetic topological device with electric field.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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