Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 234

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Single-layer spin-orbit-torque magnetization switching due to spin berry curvature generated by minute spontaneous atomic displacement in a Weyl oxide

Horiuchi, Hiroto*; Araki, Yasufumi; Wakabayashi, Yuki*; Ieda, Junichi; Yamanouchi, Michihiko*; 7 of others*

Advanced Materials, 2025, p.2416091_1 - 2416091_9, 2025/04

 Times Cited Count:0

Journal Articles

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

 Times Cited Count:0 Percentile:0.00(Physics, Multidisciplinary)

Journal Articles

Spin manipulation utilizing Weyl electrons in ferromagnetic SrRuO$$_{3}$$

Araki, Yasufumi; Ieda, Junichi

Magune, 20(1), p.12 - 17, 2025/02

Spintronics has been hindered by substantial power losses associated with the electric manipulation of spins. To mitigate Joule heating, we have developed a theory of electrically induced spin torques incorporating the topological structure of electron states. This topological contribution is free from dissipation and significantly enhances the torque efficiency per unit current compared with the conventional spin transfer torque. Our theory is supported by a magnetization switching experiment on ferromagnetic oxide SrRuO$$_{3}$$, where the observed torque is attributed to a type of topological electrons known as Weyl electrons.

Journal Articles

Electrical mutual switching in a noncollinear-antiferromagnetic-ferromagnetic heterostructure

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

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

 Times Cited Count:0 Percentile:0.00(Multidisciplinary Sciences)

Journal Articles

Towards innovation to transform radioactive waste into resources; A Way of converting heat and radiation into electricity

Ieda, Junichi; Fukada, Yukimasa; Fukuda, Tatsuo

Nihon Genshiryoku Gakkai-Shi ATOMO$$Sigma$$, 66(10), p.521 - 524, 2024/10

no abstracts in English

Journal Articles

Emergent inductance in magnetic nanostructures

Ieda, Junichi

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

no abstracts in English

Journal Articles

Emergent inductance due to spin-orbit interactions

Ieda, Junichi; Araki, Yasufumi; Yamane, Yuta*

Kotai Butsuri, 59(8), p.403 - 410, 2024/08

Journal Articles

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

 Times Cited Count:15 Percentile:96.56(Physics, Multidisciplinary)

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 Mn$$_{3}$$Sn 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 Mn$$_{3}$$Sn/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.

Journal Articles

Inelastic neutron scattering study of magnon excitation by ultrasound injection in yttrium iron garnet

Shamoto, Shinichi; Akatsu, Mitsuhiro*; Chang, L.-J.*; Nemoto, Yuichi*; Ieda, Junichi

Applied Physics Letters, 124(11), p.112402_1 - 112402_5, 2024/03

 Times Cited Count:1 Percentile:40.97(Physics, Applied)

The magnon excitation by ultrasound injection in Y$$_3$$Fe$$_5$$O$$_{12}$$ is studied by inelastic neutron scattering. Both longitudinal and transverse ultrasound injections enhanced the inelastic neutron scattering intensity.

Journal Articles

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

Journal Articles

Magnetic hysteresis induction with nanocolumnar defects in magnetic insulators

Harii, Kazuya*; Umeda, Maki; Arisawa, Hiroki*; Hioki, Tomosato*; Sato, Nana; Okayasu, Satoru; Ieda, Junichi

Journal of the Physical Society of Japan, 92(7), p.073701_1 - 073701_4, 2023/07

 Times Cited Count:1 Percentile:23.32(Physics, Multidisciplinary)

Journal Articles

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

 Times Cited Count:0 Percentile:0.00(Physics, Multidisciplinary)

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).

Journal Articles

Magnetization switching process by dual spin-orbit torque in interlayer exchange-coupled systems

Masuda, Hiroto*; Yamane, Yuta*; Seki, Takeshi*; Raab, K.*; Dohi, Takaaki*; Modak, R.*; Uchida, Kenichi*; Ieda, Junichi; Kl$"a$ui, M.*; Takanashi, Koki

Applied Physics Letters, 122(16), p.162402_1 - 162402_7, 2023/04

 Times Cited Count:3 Percentile:39.87(Physics, Applied)

Journal Articles

Thermal stability of non-collinear antiferromagnetic Mn$$_3$$Sn 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

 Times Cited Count:5 Percentile:58.52(Physics, Applied)

Journal Articles

Spin and spin current; From fundamentals to recent progress

Maekawa, Sadamichi; Kikkawa, Takashi*; Chudo, Hiroyuki; Ieda, Junichi; Saito, Eiji

Journal of Applied Physics, 133(2), p.020902_1 - 020902_24, 2023/01

 Times Cited Count:24 Percentile:93.17(Physics, Applied)

Journal Articles

The Damage analysis for irradiation tolerant spin-driven thermoelectric device based on single-crystalline Y$$_3$$Fe$$_5$$O$$_{12}$$/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

 Times Cited Count:1 Percentile:9.88(Engineering, Electrical & Electronic)

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 Y$$_3$$Fe$$_5$$O$$_{12}$$/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 $$10^{10}$$ ions/cm$$^2$$ fluence and that the SSE signal is extinguished around $$10^{12}$$ ions/cm$$^2$$, 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 Y$$_3$$Fe$$_5$$O$$_{12}$$/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 Y$$_3$$Fe$$_5$$O$$_{12}$$/Pt for developing better STE devices applicable to harsh environmental usages.

Journal Articles

Local bifurcation with spin-transfer torque in superparamagnetic tunnel junctions

Funatsu, Takuya*; Kanai, Shun*; Ieda, Junichi; Fukami, Shunsuke*; Ohno, Hideo*

Nature Communications (Internet), 13, p.4079_1 - 4079_8, 2022/07

AA2021-0782.pdf:1.86MB

 Times Cited Count:9 Percentile:59.76(Multidisciplinary Sciences)

Modulation of the energy landscape by external perturbations governs various thermally-activated phenomena, described by the Arrhenius law. Thermal fluctuation of nanoscale magnetic tunnel junctions with spin-transfer torque (STT) shows promise for unconventional computing, whereas its rigorous representation, based on the Neel-Arrhenius law, has been controversial. In particular, the exponents for thermally-activated switching rate therein, have been inaccessible with conventional thermally-stable nanomagnets with decade-long retention time. Here we approach the Neel-Arrhenius law with STT utilising superparamagnetic tunnel junctions that have high sensitivity to external perturbations and determine the exponents through several independent measurements including homodyne-detected ferromagnetic resonance, nanosecond STT switching, and random telegraph noise. Furthermore, we show that the results are comprehensively described by a concept of local bifurcation observed in various physical systems. The findings demonstrate the capability of superparamagnetic tunnel junction as a useful tester for statistical physics as well as sophisticated engineering of probabilistic computing hardware with a rigorous mathematical foundation.

Journal Articles

Large antisymmetric interlayer exchange coupling enabling perpendicular magnetization switching by an in-plane magnetic field

Masuda, Hiroto*; Seki, Takeshi*; Yamane, Yuta*; Modak, R.*; Uchida, Kenichi*; Ieda, Junichi; Lau, Y.-C.*; Fukami, Shunsuke*; Takanashi, Koki

Physical Review Applied (Internet), 17(5), p.054036_1 - 054036_9, 2022/05

 Times Cited Count:9 Percentile:59.76(Physics, Applied)

The antisymmetric interlayer exchange coupling (AIEC) was recently discovered, playing pivotal roles in magnetization switching of a synthetic antiferromagnet (SAF) through inducing magnetization canting. Large AIEC is reported for perpendicularly magnetized Pt/Co/Ir/Co/Pt with wedge-shaped layers. The effective field of the AIEC is related with symmetric interlayer exchange coupling, providing guides to enhance the AIEC. We develop an extended Stoner-Wohlfarth model for a SAF, revealing key factors in its magnetization switching. Combining the theoretical knowledge and the experimental results, perpendicular magnetization switching is achieved solely by an in-plane magnetic field.

Journal Articles

Observation of domain structure in non-collinear antiferromagnetic Mn$$_3$$Sn thin films by magneto-optical Kerr effect

Uchimura, Tomohiro*; Yoon, J.-Y.*; Sato, Yuma*; Takeuchi, Yutaro*; Kanai, Shun*; Takechi, Ryota*; Kishi, Keisuke*; Yamane, Yuta*; DuttaGupta, S.*; Ieda, Junichi; et al.

Applied Physics Letters, 120(17), p.172405_1 - 172405_5, 2022/04

 Times Cited Count:24 Percentile:88.93(Physics, Applied)

Journal Articles

Theory of Emergent Inductance with Spin-Orbit Coupling Effects

Yamane, Yuta*; Fukami, Shunsuke*; Ieda, Junichi

Physical Review Letters, 128(14), p.147201_1 - 147201_6, 2022/04

 Times Cited Count:9 Percentile:71.27(Physics, Multidisciplinary)

We extend the theory of emergent inductance, which has recently been discovered in spiral magnets, to arbitrary magnetic textures by taking into account spin-orbit couplings arising in the absence of spatial inversion symmetry. We propose a new concept of spin-orbit emergent inductance, which can be formulated as originating from a dynamical Aharonov-Casher phase of an electron in ferromagnets. The spin-orbit emergent inductance universally arises in the coexistence of magnetism and the spin-orbit couplings, even with spatially uniform magnetization, allowing its stable operation in wide ranges of temperature and frequency. Revisiting the widely studied systems involving ferromagnets with spatial inversion asymmetry, with the new perspective offered by our work, will lead to opening a new paradigm in the study of spin-orbit physics and the spintronics-based power management in ultrawideband frequency range.

234 (Records 1-20 displayed on this page)