Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interface

Spin–orbit torque (SOT) is a fundamental phenomenon in spintronics, facilitating efficient control of magnetic states in advanced device architectures. The discovery of a large spin Hall angle in metastable heavy metals has significantly enhanced the potential of SOT-based devices. However, the inhe...

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Main Authors: Taishiro Yamazaki, Sora Obinata, Riku Iimori, Kazumasa Yamada, Takashi Kimura
Format: Article
Language:English
Published: AIP Publishing LLC 2025-06-01
Series:APL Materials
Online Access:http://dx.doi.org/10.1063/5.0258083
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author Taishiro Yamazaki
Sora Obinata
Riku Iimori
Kazumasa Yamada
Takashi Kimura
author_facet Taishiro Yamazaki
Sora Obinata
Riku Iimori
Kazumasa Yamada
Takashi Kimura
author_sort Taishiro Yamazaki
collection DOAJ
description Spin–orbit torque (SOT) is a fundamental phenomenon in spintronics, facilitating efficient control of magnetic states in advanced device architectures. The discovery of a large spin Hall angle in metastable heavy metals has significantly enhanced the potential of SOT-based devices. However, the inherently low electrical conductivity of these materials poses a critical obstacle to achieving efficient device performance. To overcome this limitation, we systematically investigate interfacial Rashba spin–orbit interactions at the interfaces between metastable heavy metals and highly conductive normal metals through a combination of theoretical and experimental approaches. First-principles calculations demonstrate that interfaces involving β-phase tungsten (β-W) and tantalum (β-Ta) exhibit substantially enhanced Rashba interactions compared to their α-phase counterparts. This enhancement is attributed to modifications in the interfacial electric field. Furthermore, we provide the first clear evidence of a positive correlation between the Rashba parameter and the interfacial work-function. These findings highlight the potential of engineering metastable interfacial structures to optimize spin–orbit coupling, enabling precise spin current control. This advancement offers a promising pathway for the development of high-performance spintronic devices and the realization of next-generation spin-based electronics.
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id doaj-art-3fad67631f3c40d3877c6a9bf55a3155
institution OA Journals
issn 2166-532X
language English
publishDate 2025-06-01
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series APL Materials
spelling doaj-art-3fad67631f3c40d3877c6a9bf55a31552025-08-20T02:37:33ZengAIP Publishing LLCAPL Materials2166-532X2025-06-01136061123061123-510.1063/5.0258083Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interfaceTaishiro Yamazaki0Sora Obinata1Riku Iimori2Kazumasa Yamada3Takashi Kimura4Department of Physics, Kyushu University, 744 Motooka, Fukuoka 819-0395, JapanDepartment of Physics, Kyushu University, 744 Motooka, Fukuoka 819-0395, JapanDepartment of Physics, Kyushu University, 744 Motooka, Fukuoka 819-0395, JapanDepartment of Physics, Kyushu University, 744 Motooka, Fukuoka 819-0395, JapanDepartment of Physics, Kyushu University, 744 Motooka, Fukuoka 819-0395, JapanSpin–orbit torque (SOT) is a fundamental phenomenon in spintronics, facilitating efficient control of magnetic states in advanced device architectures. The discovery of a large spin Hall angle in metastable heavy metals has significantly enhanced the potential of SOT-based devices. However, the inherently low electrical conductivity of these materials poses a critical obstacle to achieving efficient device performance. To overcome this limitation, we systematically investigate interfacial Rashba spin–orbit interactions at the interfaces between metastable heavy metals and highly conductive normal metals through a combination of theoretical and experimental approaches. First-principles calculations demonstrate that interfaces involving β-phase tungsten (β-W) and tantalum (β-Ta) exhibit substantially enhanced Rashba interactions compared to their α-phase counterparts. This enhancement is attributed to modifications in the interfacial electric field. Furthermore, we provide the first clear evidence of a positive correlation between the Rashba parameter and the interfacial work-function. These findings highlight the potential of engineering metastable interfacial structures to optimize spin–orbit coupling, enabling precise spin current control. This advancement offers a promising pathway for the development of high-performance spintronic devices and the realization of next-generation spin-based electronics.http://dx.doi.org/10.1063/5.0258083
spellingShingle Taishiro Yamazaki
Sora Obinata
Riku Iimori
Kazumasa Yamada
Takashi Kimura
Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interface
APL Materials
title Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interface
title_full Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interface
title_fullStr Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interface
title_full_unstemmed Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interface
title_short Significant enhancement of Rashba spin–orbit interaction using metastable heavy metal interface
title_sort significant enhancement of rashba spin orbit interaction using metastable heavy metal interface
url http://dx.doi.org/10.1063/5.0258083
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AT kazumasayamada significantenhancementofrashbaspinorbitinteractionusingmetastableheavymetalinterface
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