Efficient manipulation of magnetic domain wall by dual spin-orbit torque in synthetic antiferromagnets

Masuda, Hiroto*; Yamane, Yuta*; Dohi, Takaaki*; Yamazaki, Takumi*; Modak, R.*; Uchida, Kenichi*; Ieda, Junichi; Klui, M.*; Takanashi, Koki; Seki, Takeshi*

Advanced Science (Internet), p.e14598_1 - e14598_9, 2025/10

https://doi.org/10.1002/advs.202514598

Electrical coherent driving of chiral antiferromagnet

Takeuchi, Yutaro*; Sato, Yuma*; Yamane, Yuta*; Yoon, J.-Y.*; Kanno, Yukinori*; Uchimura, Tomohiro*; De Zoysa, K. V.*; Han, J.*; Kanai, Shun*; Ieda, Junichi; et al.

Science, 389(6762), p.830 - 834, 2025/08

https://doi.org/10.1126/science.ado1611

Symmetry-reduced topological interface for unleashing a multidirectional spin-orbit torque

Sugimoto, Satoshi*; Araki, Yasufumi; Takahashi, Yukiko*; Ieda, Junichi; Kasai, Shinya*

Communications Physics (Internet), 8, p.100_1 - 100_9, 2025/03

https://doi.org/10.1038/s42005-025-02024-1

Electrical mutual switching in a noncollinear-antiferromagnetic-ferromagnetic heterostructure

Yoon, J.-Y.*; Takeuchi, Yutaro*; Takechi, Ryota*; Han, J.*; Uchimura, Tomohiro*; Yamane, Yuta*; Kanai, Shun*; Ieda, Junichi; Ohno, Hideo*; Fukami, Shunsuke*

Nature Communications (Internet), 16, p.1171_1 - 1171_8, 2025/02

https://doi.org/10.1038/s41467-025-56157-6

Emergent inductance in magnetic nanostructures

Ieda, Junichi

Nihon Juki Gakkai Kenkyukai Shiryo, 250, p.1 - 5, 2024/10

no abstracts in English

Room-temperature flexible manipulation of the quantum-metric structure in a topological chiral antiferromagnet

Han, J.*; Uchimura, Tomohiro*; Araki, Yasufumi; Yoon, J.-Y.*; Takeuchi, Yutaro*; Yamane, Yuta*; Kanai, Shun*; Ieda, Junichi; Ohno, Hideo*; Fukami, Shunsuke*

Nature Physics, 20(7), p.1110 - 1117, 2024/07

https://doi.org/10.1038/s41567-024-02476-2

Quantum metric and Berry curvature are two fundamental and distinct factors to describe the geometry of quantum eigenstates. While Berry curvature is known for playing crucial roles in several condensed-matter states, quantum metric, which was predicted to induce new classes of topological phenomena, has rarely been touched, particularly in an ambient circumstance. Using a topological chiral antiferromagnet MnSn adjacent to Pt, at room temperature, we successfully manipulate the quantum-metric structure of electronic states through its interplay with the nanoscale spin texture at the MnSn/Pt interface. This is manifested by a time-reversal-odd second-order Hall effect that is robust against extrinsic electron scattering, in contrast to any transport effects from the Berry curvature. We also verify the flexibility of controlling the quantum-metric structure, as the interacting spin texture can be tuned by moderate magnetic fields or by interface engineering via spin-orbit interactions. Our work paves a way for harnessing the quantum-metric structure to unveil emerging topological physics in practical environments and to build applicable nonlinear devices.

Spinning off common sense; From coil-free inductors to semi-permanent power supplies

Ieda, Junichi

Kozan, 77(1), p.15 - 23, 2024/01

no abstracts in English

Emergence of inductance and capacitance from topological electromagnetism

Araki, Yasufumi; Ieda, Junichi

Journal of the Physical Society of Japan, 92(7), p.074705_1 - 074705_9, 2023/06

https://doi.org/10.7566/JPSJ.92.074705

Topological electromagnetism owing to nontrivial momentum-space topology of electrons in insulators gives rise to diverse anomalous magnetoelectric responses. While conventional inductors and capacitors are based on classical electromagnetism described by Maxwell's equations, here we show that topological electromagnetism in combination with spin dynamics in magnets also generates an inductance or a capacitance. We build a generic framework to extract the complex impedance on the basis of topological field theory, and demonstrate the emergence of an inductance or a capacitance in several heterostructure setups. In comparison with the previously-studied emergent inductances in metallic magnets, insulators highly suppress the power loss, because of the absence of Joule heating. We show that the inductance from topological electromagnetism is achieved at low current and high frequency, and is also advantageous in its power efficiency, as characterized by the high quality factor (Q-factor).

Thermal stability of non-collinear antiferromagnetic MnSn nanodot

Sato, Yuma*; Takeuchi, Yutaro*; Yamane, Yuta*; Yoon, J.-Y.*; Kanai, Shun*; Ieda, Junichi; Ohno, Hideo*; Fukami, Shunsuke*

Applied Physics Letters, 122(12), p.122404_1 - 122404_5, 2023/03

https://doi.org/10.1063/5.0135709

The Damage analysis for irradiation tolerant spin-driven thermoelectric device based on single-crystalline YFeO/Pt heterostructures

Ieda, Junichi; Okayasu, Satoru; Harii, Kazuya*; Kobata, Masaaki; Yoshii, Kenji; Fukuda, Tatsuo; Ishida, Masahiko*; Saito, Eiji

IEEE Transactions on Magnetics, 58(8), p.1301106_1 - 1301106_6, 2022/08

BB2021-0945.pdf:1.19MB

https://doi.org/10.1109/TMAG.2022.3145888

The combination of spin-driven thermoelectric (STE) devices based on spin Seebeck effect (SSE), and radioactive isotopes as heat sources, has potential as a next-generation method of power generation in applications such as power supplies for space probes. However, there has been very limited knowledge available indicating the irradiation tolerance of spin thermoelectric devices. Through analysis using a heavy ion-beam accelerator and the hard X-ray photoemission spectroscopy (HAXPES) measurements, we show that a prototypical STE device based on YFeO/Pt heterostructures has tolerance to irradiation of high-energy heavy-ion beams. We used 320 MeV gold ion beams modeling cumulative damages due to fission products emitted from the surface of spent nuclear fuels. By varying the dose level, we confirmed that the thermoelectric and magnetic properties of the SSE elements are not affected by the ion-irradiation dose up to ions/cm fluence and that the SSE signal is extinguished around ions/cm, in which the ion tracks almost fully cover the sample surface. In addition, the HAXPES measurements were performed to understand the effects at the interface of YFeO/Pt. The HAXPES measurements suggest that the chemical reaction that diminishes the SSE signals is enhanced with the increase of the irradiation dose. We share the current understandings of the damage analysis in YFeO/Pt for developing better STE devices applicable to harsh environmental usages.