ウエスギ リョウタ上杉 良太助教Ryota Uesugi
■研究者基本情報
学歴
経歴
外部リンク
■研究活動情報
受賞
論文
- Observation of Omnidirectional Exchange Bias at All‐Antiferromagnetic Polycrystalline Heterointerface
Mihiro Asakura; Tomoya Higo; Takumi Matsuo; Ryota Uesugi; Daisuke Nishio‐Hamane; Satoru Nakatsuji
Advanced Materials, 2024年07月 - Large spontaneous magneto-thermoelectric effect in epitaxial thin films of the topological kagome ferromagnet Fe3Sn
Shun'ichiro Kurosawa; Tomoya Higo; Shota Saito; Ryota Uesugi; Satoru Nakatsuji
Physical Review Materials, 2024年05月28日 - Observation of Cluster Magnetic Octupole Domains in the Antiferromagnetic Weyl Semimetal Mn3Sn Nanowire
Hironari Isshiki; Nico Budai; Ayuko Kobayashi; Ryota Uesugi; Tomoya Higo; Satoru Nakatsuji; YoshiChika Otani
Physical Review Letters, 2024年05月23日 - Anisotropic anomalous transport in the kagome-based topological antiferromagnetic Mn3Ga epitaxial thin films
M. Raju; Ralph Romero; Daisuke Nishio-Hamane; Ryota Uesugi; Mihiro Asakura; Zhenisbek Tagay; Tomoya Higo; N. P. Armitage; Collin Broholm; Satoru Nakatsuji
Physical Review Materials, 2024年01月26日 - Giant anomalous Nernst effect in polycrystalline thin films of the Weyl ferromagnet Co2MnGa
Ryota Uesugi; Tomoya Higo; Satoru Nakatsuji
Applied Physics Letters, 2023年12月18日 - Roll‐to‐Roll Printing of Anomalous Nernst Thermopile for Direct Sensing of Perpendicular Heat Flux
Hirokazu Tanaka; Tomoya Higo; Ryota Uesugi; Kazuto Yamagata; Yosuke Nakanishi; Hironobu Machinaga; Satoru Nakatsuji, Abstract
The anomalous Nernst effect (ANE) converts heat flux perpendicular to the plane into electricity, in sharp contrast with the Seebeck effect (SE), enabling mass production, large area, and flexibility of their devices through ordinary thin‐film fabrication techniques. Heat flux sensors, one of the most promising applications of ANE, are powerful devices for evaluating heat flow and can lead to energy savings through efficient thermal management. In reality, however, SE caused by the in‐plane heat flux is always superimposed on the measurement signal, making it difficult to evaluate the perpendicular heat flux. Here, ANE‐type heat flux sensors that selectively detect a perpendicular heat flux are fabricated by adjusting the net Seebeck coefficient in their thermopile circuit with mass‐producible roll‐to‐roll sputtering methods. The direct sensing of perpendicular heat flux using ANE‐based flexible thermopiles, as well as their simple fabrication process, paves the way for the practical application of thin‐film thermoelectric devices., Wiley
Advanced Materials, 2023年07月24日 - Magnetic imaging by the anomalous Nernst effect using atomic force microscopy
Nico Budai; Hironari Isshiki; Ryota Uesugi; Zheng Zhu; Tomoya Higo; Satoru Nakatsuji; YoshiChika Otani, IEEE
2023 IEEE International Magnetic Conference - Short Papers (INTERMAG Short Papers), 2023年05月 - High-resolution magnetic imaging by mapping the locally induced anomalous Nernst effect using atomic force microscopy
Nico Budai; Hironari Isshiki; Ryota Uesugi; Zheng Zhu; Tomoya Higo; Satoru Nakatsuji; YoshiChika Otani
Applied Physics Letters, 2023年03月06日 - Determination of spin Hall angle in the Weyl ferromagnet Co2MnGa by taking into account the thermoelectric contributions
Hironari Isshiki; Zheng Zhu; Hayato Mizuno; Ryota Uesugi; Tomoya Higo; Satoru Nakatsuji; YoshiChika Otani, American Physical Society (APS)
Physical Review Materials, 2022年08月29日 - Omnidirectional Control of Large Electrical Output in a Topological Antiferromagnet
Tomoya Higo; Yufan Li; Kouta Kondou; Danru Qu; Muhammad Ikhlas; Ryota Uesugi; Daisuke Nishio‐Hamane; C. L. Chien; YoshiChika Otani; Satoru Nakatsuji, Abstract
Control of magnetization direction is essential for the wide application of ferromagnets; it defines the signal size of memory and sensor. However, the magnetization itself causes a dilemma. While its size matters to obtain strong responses upon its reversal, the large magnetization concomitantly suppresses the range of its directional control because of the demagnetizing field. On the other hand, realization of the desired magnetic anisotropy requires careful engineering of crystalline and interfacial effects to overcome the demagnetization barrier. Thus, it would be ideal if one could find alternative magnets that carry no magnetization but strong responses. The discovery of a topological metallic state in the antiferromagnet Mn3Sn is significant; they host a large Berry curvature in momentum space, enabling the observation of disproportionately large transverse responses such as anomalous Hall and Nernst effects, the key functionalities for replacing ferromagnets in the magnetic devices. Here, the experimental realization of omnidirectional control of the large responses in an antiferromagnet is reported. In particular, it is demonstrated that the absence of shape anisotropy enables the omnidirectional control, and lifts the shape constraint in designing the magnetic devices. This work lays the technological foundation for developing simple‐structured high‐performance devices including multi‐level memory and heat flux sensor., Wiley
Advanced Functional Materials, 2021年02月25日 - Electrical fluctuation spectra due to characteristic thermal diffusion in Ta thin films deposited by RF-magnetron sputtering
Ryota Uesugi; Takashi Komine; Masaomi Mizuno; Ryo Ando; Hideo Akabane, IOP Publishing
Japanese Journal of Applied Physics, 2020年02月01日
講演・口頭発表等
- Observation of the giant anomalous Nernst effect in the Weyl ferromagnet Co2MnGa polycrystalline films
Ryota Uesugi; Tomoya Higo; Satoru Nakatsuji
The 85th JSAP Autumn Meeting, 2024年09月20日
20240916, 20240920 - Large anomalous Nernst effect in polycrystalline thin films of the Weyl ferromagnet Co2MnGa
Ryota Uesugi; Tomoya Higo; Satoru Nakatsuji
APS March Meeting 2024, 2024年03月04日
20240303, 20240308 - Giant anomalous Nernst effect in the epitaxial and polycrystalline films of the Weyl ferromagnet Co2MnGa
Ryota Uesugi; Tomoya Higo; Satoru Nakatsuji
International Symposium on Quantum Electronics 2024, 2024年02月14日
20240213, 20240216 - ワイル強磁性体Co2MnGa 薄膜における トポロジカル電子構造に由来した横熱電応答の規則度依存性
上杉良太; 肥後友也; 見波将; 浜根大輔; 朱政; 朝倉海寛; 酒井明人; 大谷義近; 有田亮太郎; 中辻知
日本物理学会 第78回年次大会, 2023年09月17日
20230916, 20230919 - Logarithmic temperature dependence of transverse thermoelectric transport in the Weyl ferromagnet Co2MnGa thin film
Ryota Uesugi; Tomoya Higo; Susumu Minami; Daisuke Nishio-Hamane; Zheng Zhu; Mihiro Asakura; Akito Sakai; Yoshichika Otani; Ryotaro Arita; Satoru Nakatsuji
11th International Symposium on Metallic Multilayers, 2023年07月25日
20230724, 20230728 - ワイル強磁性体Co2MnGa 薄膜における 巨大異常ネルンスト効果と量子臨界スケーリング
上杉良太; 肥後友也; 見波将; 浜根大輔; 朱 政; 朝倉海寛; 酒井明人; 大谷義近; 有田亮太郎; 中辻知
「スピントロニクス学術研究基盤と連携ネットワーク（Spin-RNJ）」シンポジウム, 2023年03月20日
20230320, 20230321 - 〔主要な業績〕Observation of large anomalous Nernst effect and quantum-critical scaling in the Weyl ferromagnet Co2MnGa thin films
Ryota Uesugi; Tomoya Higo; Susumu Minami; Daisuke Nishio-Hamane; Zheng Zhu; Mihiro Asakura; Akito Sakai; Yoshichika Otani; Ryotaro Arita; Satoru Nakatsuji
The 70th JSAP Spring Meeting, 2023年03月17日
20230315, 20230318 - Atomic ordering dependence of anomalous Nernst effect in thin films ofthe Weyl magnet Co2MnGa
Ryota Uesugi; Tomoya Higo; Satoru Nakatsuji
2nd International Symposium on Trans-Scale Quantum Science (TSQS2022), 2022年11月08日
20221108, 20221111 - Composition dependence of anomalous Nernst effect in the Weyl magnetic material Co2MnGa thin film
Ryota Uesugi; Tomoya Higo; Zheng Zhu; Mihiro Asakura; Akito Sakai; Daisuke Nishio-Hamane; Yoshichika Otani; Satroru Nakatsuji
The 15th Asia Pacific Physics Conference, 2022年08月26日
20220821, 20220826 - ワイル磁性体Co2MnGa 薄膜における横磁気熱電効果
上杉 良太; 肥後友也; 中辻 知
第１３回 低温科学研究センター研究交流会, 2022年03月09日
20220309, 20220309 - ワイル強磁性体Co2MnGa 薄膜の面内/面直熱流下での異常ネルンスト効果
上杉 良太; 肥後 友也; 朱 政; 近藤 浩太; 酒井 明人; 朝倉 海寛; 大谷 義近; 中辻 知
第81回 応用物理学会秋季学術講演会, 2020年09月08日
20200908, 20200911 - フルホイスラー合金Co2MnGa における異常ネルンスト効果の規則度依存性
上杉 良太; 肥後 友也; 朱 政; 近藤 浩太; 大谷 義近; 中辻 知
第67回 応用物理学会春季学術講演会, 2020年03月13日
20200312, 20200315 - スパッタリングで形成したTa薄膜における電気抵抗率の歪み誘起1/f 雑音
上杉 良太; 小峰 啓史; 水野 将臣; 安藤 亮; 赤羽 秀郎
第66回 応用物理学会春季学術講演会, 2019年03月10日
20190309, 20190312
共同研究・競争的資金等の研究課題
