Spin-filter induced large magnetoresistance in 2D van der Waals magnetic tunnel junctions
Spin-filter induced large magnetoresistance in 2D van der Waals magnetic tunnel junctions
复制标题
二维范德华磁隧道结中旋转滤波器引起的大磁阻
DOI：
10.1039/d0nr07290g
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发表时间：
2021
期刊：
影响因子：
6.7
通讯作者：
Zhao Weisheng
中科院分区：
文献类型：
--
作者：
Yang Wei;Cao Yuan;Han Jiangchao;Lin Xiaoyang;Wang Xinhe;Wei Guodong;Lv Chen;Bournel Arnaud;Zhao Weisheng
二维货车德瓦耳斯（vdW）异质结构是一种以精确选择的顺序逐层堆叠的二维材料，由于其超洁净的界面、独特的电子性质和二维铁磁性，在自旋电子学领域受到越来越多的关注。基于最近合成的具有铁磁有序性和高于室温的高居里温度的单层1 T-VSe 2，我们利用密度泛函理论结合非平衡绿色函数方法研究了偏压驱动下基于VSe 2的二维磁性隧道结（MTJ）的自旋输运性质.在1 T-MoSe_2/1 T-VSe_2/2 H-WSe_2/1 T-VSe_2/1 T-MoSe_2器件中，隧道磁阻（TMR）高达5600%。基于对倏逝态的分析，这种大的TMR归因于1 T-VSe 2和2 H-WSe 2之间界面处的自旋过滤效应，该效应克服了1 T-VSe 2的低自旋极化。此外，通过插入2 H-MoSe 2，自旋过滤器效应随着电流的减小而增强，并且TMR急剧提高到1.7 × 105%。这项工作突出了2D vdW异质结的超低功耗自旋电子应用的电子结构工程的可行性。
Two-dimensional (2D) van der Waals (vdW) heterostructures, known as layer-by-layer stacked 2D materials in a precisely chosen sequence, have received more and more attention in spintronics for their ultra-clean interface, unique electronic properties and 2D ferromagnetism. Motivated by the recent synthesis of monolayer 1T-VSe2 with ferromagnetic ordering and a high Curie temperature above room temperature, we investigate the bias-voltage driven spin transport properties of 2D magnetic tunnel junctions (MTJs) based on VSe2 utilizing density functional theory combined with the nonequilibrium Green's function method. In the device 1T-MoSe2/1T-VSe2/2H-WSe2/1T-VSe2/1T-MoSe2, the tunneling magneto-resistance (TMR) is incredibly satisfactory up to 5600%. Based on the analysis of evanescent states, this large TMR is attributed to the spin filter effect at the interface between 1T-VSe2 and 2H-WSe2, which overcomes the low spin polarization of 1T-VSe2. Furthermore, by inserting 2H-MoSe2, the spin filter effect is enhanced with decreasing current and the TMR is drastically improved to 1.7 × 105%. This work highlights the feasibility of 2D vdW heterostructures for ultra-low power spintronic applications by electronic structural engineering.