{"title":"Quantum-well resonances caused by partial confinement in MgO-based magnetic tunnel junctions","authors":"L. N. Jiang, B. Y. Chi, W. Z. Chen, X. F. Han","doi":"10.1103/physrevb.110.094428","DOIUrl":null,"url":null,"abstract":"Quantum-well resonance is achieved through partial confinement in magnetic tunnel junctions (MTJs), which provides an additional operable degree of freedom to regulate quantum-well levels. Using Al/Fe/MgO/Fe/Al and Ag/Al/Fe/MgO/Fe/Al/Ag MTJs as examples, via first-principles calculations, we demonstrate that the partial confinement of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi mathvariant=\"normal\">Δ</mi><mn>1</mn></msub></math> electrons at the Al/Fe interface, and the full confinement at the Fe/MgO interface combine to produce quantum-well resonances in Fe. The quantum-well levels of Fe can be periodically adjusted by two degrees of freedom: Fe and Al thickness. The oscillation period obtained from conductance <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>G</mi><mrow><mo>↑</mo><mo>↑</mo></mrow></msub></math> of MTJs is 2.13 ML Fe (9 ML Al), close to 2.25 ML Fe (8.33 ML Al) calculated by Fermi wave vector in the bcc-Fe (fcc-Al) band. The combination of long and short periods enables quantum-well levels to be finely adjusted. An ultrahigh optimistic TMR effect of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mn>3.05</mn><mo>×</mo><msup><mn>10</mn><mn>5</mn></msup></mrow></math>% is achieved. Our results provide a way for designing high-performance spintronics devices.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review B","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physrevb.110.094428","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
Abstract
Quantum-well resonance is achieved through partial confinement in magnetic tunnel junctions (MTJs), which provides an additional operable degree of freedom to regulate quantum-well levels. Using Al/Fe/MgO/Fe/Al and Ag/Al/Fe/MgO/Fe/Al/Ag MTJs as examples, via first-principles calculations, we demonstrate that the partial confinement of electrons at the Al/Fe interface, and the full confinement at the Fe/MgO interface combine to produce quantum-well resonances in Fe. The quantum-well levels of Fe can be periodically adjusted by two degrees of freedom: Fe and Al thickness. The oscillation period obtained from conductance of MTJs is 2.13 ML Fe (9 ML Al), close to 2.25 ML Fe (8.33 ML Al) calculated by Fermi wave vector in the bcc-Fe (fcc-Al) band. The combination of long and short periods enables quantum-well levels to be finely adjusted. An ultrahigh optimistic TMR effect of % is achieved. Our results provide a way for designing high-performance spintronics devices.
期刊介绍:
Physical Review B (PRB) is the world’s largest dedicated physics journal, publishing approximately 100 new, high-quality papers each week. The most highly cited journal in condensed matter physics, PRB provides outstanding depth and breadth of coverage, combined with unrivaled context and background for ongoing research by scientists worldwide.
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