【公開日：2023.07.31】【最終更新日：2023.05.25】
課題データ / Project Data
課題番号 / Project Issue Number
22UT1047
利用課題名 / Title
Giant voltage-controllable magnetoresistance switching in Ge short-channel devices with epitaxial ultra-thin Fe electrodes
利用した実施機関 / Support Institute
東京大学 / Tokyo Univ.
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）加工・デバイスプロセス/Nanofabrication（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）量子・電子制御により革新的な機能を発現するマテリアル/Materials using quantum and electronic control to perform innovative functions（副 / Sub）高度なデバイス機能の発現を可能とするマテリアル/Materials allowing high-level device functions to be performed
キーワード / Keywords
Tunneling anisotropic magnetoresistance , TAMR,リソグラフィ/Lithography,高品質プロセス材料/ High quality process materials,スピン制御/ Spin control,量子効果/ Quantum effect
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
田中 雅明
所属名 / Affiliation
東京大学
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
Shun Tsuruoka
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
利用形態 / Support Type
（主 / Main）機器利用/Equipment Utilization（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
Tunneling anisotropic magnetoresistance (TAMR) is an interfacial effect between a ferromagnet and a non-magnetic material where the tunneling resistance depends on the orientation of the magnetization. Since TAMR originates from spin-orbit coupling (SOC), large TAMR is observed in materials with strong SOC such as GaMnAs, while observing large TAMR in weak SOC materials has been difficult. In this study, we fabricated and characterized a Ge-based all-epitaxial single-crystalline lateral device with a short channel.
実験 / Experimental
We have grown Fe/ MgO/ Ge:B/ Ge on a Ge (001) substrate using molecular beam epitaxy (MBE), and then we reduced the Fe layer to less than 1 nm by Ar milling to induce a perpendicular magnetic anisotropy component. We have fabricated a short-channel device with a channel length of a few tens of nm by electron beam lithography and Ar milling.
結果と考察 / Results and Discussion
In the perpendicular magnetic-field dependence of the source-drain resistance at 3 K, we observed switching between the high-resistance state and the low-resistance state at a threshold field, and it increases with the increasing voltage. The magnetoresistance (MR) ratio increases with the increasing voltage, and when it is 9 V, the MR ratio reaches over 10000%. These results suggest that the magnetoresistance switching reflects the modulation of the magnetization direction induced both by electric and magnetic fields.
図・表・数式 / Figures, Tables and Equations
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
This work was supported by Grants-in-Aid Scientific Research (21K18167, 22H04948, 23H03802), JST CREST (JPMJCR1777), JST ERATO (JPMJER2202).
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- Shun Tsuruoka, Yuriko Tadano, Le Duc Anh, Masaaki Tanaka, and Shinobu Ohya , 46 “Giant voltage-controllable magnetoresistance switching in Ge short-channel devices with epitaxial ultra-thin Fe electrodes”, 第 83 回応用物理学会秋季学術講演 会, 23p-B201-4, 東北大学川内北キャンパス, 2022/9/20-23.
- Shun Tsuruoka, Yuriko Tadano, Le Duc Anh, Masaaki Tanaka, and Shinobu Ohya, “Giant voltage-controllable magnetoresistance switching in Ge short-channel devices with epitaxial ultra-thin Fe electrodes”, The 67th Annual Conference on Magnetism and Magnetic Materials, DOA-04, the Hyatt Regency Minneapolis, October 31 - November 4, 2022.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件