Tunneling Barrier Thickness Dependence of Spin Polarization of Ferromagnet in Magnetic Tunnel Junctions  

作　　者：Yu-Qing Zhao Hai-Yan Zuo Shao-Wei Li Ke Xia Ming Wen Jun-Mei Guo Peng Xiong Cong Ren 赵宇清;左海艳;李少薇;夏珂;闻明;郭俊梅;Peng Xiong;任聪(School of Physics and Astronomy,Yunnan University,Kunming 650500,China;Department of Physics,Southeast University,Nanjing 100193,China;Kunming Institute of Precious Metals,Kunming 650019,China;Physics Department,Florida State University,Tallahassee,USA;Yunnan Key Laboratory of Eletromagnetic Materials and Devices,Yunnan University,Kunming 650500,China)

机构地区：[1]School of Physics and Astronomy,Yunnan University,Kunming 650500,China [2]Department of Physics,Southeast University,Nanjing 100193,China [3]Kunming Institute of Precious Metals,Kunming 650019,China [4]Physics Department,Florida State University,Tallahassee,USA [5]Yunnan Key Laboratory of Eletromagnetic Materials and Devices,Yunnan University,Kunming 650500,China

出　　处：《Chinese Physics Letters》2024年第11期93-98,共6页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11774303 and 11574373);the financial support from“15th Graduate Research Innovation Project”from Yunnan University;financial support from the Joint Fund of Yunnan Provincial Science and Technology Department(Grant No.2019FY003008)。

摘　　要：For designing low-impedance magnetic tunnel junctions(MTJs),it has been found that tunneling magnetoresistance strongly correlates with the insulating barrier thickness,imposing a fundamental problem about the relationship between spin polarization of ferromagnet and the insulating barrier thickness in MTJs.Here,we investigate the influence of alumina barrier thickness on tunneling spin polarization(TSP)through a combination of theoretical calculations and experimental verification.Our simulating results reveal a significant impact of barrier thickness on TSP,exhibiting an oscillating decay of TSP with the barrier layer thinning.Experimental verification is realized on FeNi/AlO_(x)/Al superconducting tunnel junctions to directly probe the spin polarization of FeNi ferromagnet using Zeeman-split tunneling spectroscopy technique.These findings provide valuable insights for designs of high-performance spintronic devices,particularly in applications such as magnetic random access memories,where precise control over the insulating barrier layer is crucial.

关 键 词：TECHNIQUE TUNNELING POLARIZATION 

分 类 号：O469[理学—凝聚态物理]