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Masuda H, Seki T, Ohe JI, Nii Y, Masuda H, Takanashi K, Onose Y. Room temperature chirality switching and detection in a helimagnetic MnAu 2 thin film. Nat Commun 2024; 15:1999. [PMID: 38453940 PMCID: PMC10920692 DOI: 10.1038/s41467-024-46326-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/22/2024] [Indexed: 03/09/2024] Open
Abstract
Helimagnetic structures, in which the magnetic moments are spirally ordered, host an internal degree of freedom called chirality corresponding to the handedness of the helix. The chirality seems quite robust against disturbances and is therefore promising for next-generation magnetic memory. While the chirality control was recently achieved by the magnetic field sweep with the application of an electric current at low temperature in a conducting helimagnet, problems such as low working temperature and cumbersome control and detection methods have to be solved in practical applications. Here we show chirality switching by electric current pulses at room temperature in a thin-film MnAu2 helimagnetic conductor. Moreover, we have succeeded in detecting the chirality at zero magnetic fields by means of simple transverse resistance measurement utilizing the spin Berry phase in a bilayer device composed of MnAu2 and a spin Hall material Pt. These results may pave the way to helimagnet-based spintronics.
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Affiliation(s)
- Hidetoshi Masuda
- Institute for Materials Research, Tohoku University, Sendai, Japan.
| | - Takeshi Seki
- Institute for Materials Research, Tohoku University, Sendai, Japan.
| | - Jun-Ichiro Ohe
- Department of Physics, Toho University, Funabashi, Japan
| | - Yoichi Nii
- Institute for Materials Research, Tohoku University, Sendai, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Hiroto Masuda
- Institute for Materials Research, Tohoku University, Sendai, Japan
| | - Koki Takanashi
- Institute for Materials Research, Tohoku University, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Sendai, Japan
- Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Yoshinori Onose
- Institute for Materials Research, Tohoku University, Sendai, Japan.
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Shiota K, Inui A, Hosaka Y, Amano R, Ōnuki Y, Hedo M, Nakama T, Hirobe D, Ohe JI, Kishine JI, Yamamoto HM, Shishido H, Togawa Y. Chirality-Induced Spin Polarization over Macroscopic Distances in Chiral Disilicide Crystals. Phys Rev Lett 2021; 127:126602. [PMID: 34597079 DOI: 10.1103/physrevlett.127.126602] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 07/22/2021] [Indexed: 05/20/2023]
Abstract
A spin-polarized state is examined under charge current at room temperature without magnetic fields in chiral disilicide crystals NbSi_{2} and TaSi_{2}. We found that a long-range spin transport occurs over ten micrometers in these inorganic crystals. A distribution of crystalline grains of different handedness is obtained via location-sensitive electrical transport measurements. The sum rule holds in the conversion coefficient in the current-voltage characteristics. A diamagnetic nature of the crystals supports that the spin polarization is not due to localized electron spins but due to itinerant electron spins. A large difference in the strength of antisymmetric spin-orbit interaction associated with 4d electrons in Nb and 5d ones in Ta is oppositely correlated with that of the spin polarization. A robust protection of the spin polarization occurs over long distances in chiral crystals.
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Affiliation(s)
- Kohei Shiota
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Akito Inui
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Yuta Hosaka
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Ryoga Amano
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Yoshichika Ōnuki
- Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
- RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
| | - Masato Hedo
- Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Takao Nakama
- Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Daichi Hirobe
- Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
| | - Jun-Ichiro Ohe
- Department of Physics, Toho University, Chiba 274-8510, Japan
| | - Jun-Ichiro Kishine
- Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
- Division of Natural and Environmental Sciences, The Open University of Japan, Chiba 261-8586, Japan
| | - Hiroshi M Yamamoto
- Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
| | - Hiroaki Shishido
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Yoshihiko Togawa
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
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Inui A, Aoki R, Nishiue Y, Shiota K, Kousaka Y, Shishido H, Hirobe D, Suda M, Ohe JI, Kishine JI, Yamamoto HM, Togawa Y. Chirality-Induced Spin-Polarized State of a Chiral Crystal CrNb_{3}S_{6}. Phys Rev Lett 2020; 124:166602. [PMID: 32383920 DOI: 10.1103/physrevlett.124.166602] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 03/31/2020] [Indexed: 05/20/2023]
Abstract
Chirality-induced spin transport phenomena are investigated at room temperature without magnetic fields in a monoaxial chiral dichalcogenide CrNb_{3}S_{6}. We found that spin polarization occurs in these chiral bulk crystals under a charge current flowing along the principal c axis. Such phenomena are detected as an inverse spin Hall signal which is induced on the detection electrode that absorbs polarized spin from the chiral crystal. The inverse response is observed when applying the charge current into the detection electrode. The signal sign reverses in the device with the opposite chirality. Furthermore, the spin signals are found over micrometer length scales in a nonlocal configuration. Such a robust generation and protection of the spin-polarized state is discussed based on a one-dimensional model with an antisymmetric spin-orbit coupling.
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Affiliation(s)
- Akito Inui
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Ryuya Aoki
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Yuki Nishiue
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Kohei Shiota
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Yusuke Kousaka
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Hiroaki Shishido
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
| | - Daichi Hirobe
- Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
| | - Masayuki Suda
- Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
| | - Jun-Ichiro Ohe
- Department of Physics, Toho University, Chiba 274-8510, Japan
| | - Jun-Ichiro Kishine
- Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
- Division of Natural and Environmental Sciences, The Open University of Japan, Chiba, 261-8586, Japan
| | - Hiroshi M Yamamoto
- Research Center of Integrative Molecular Systems, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
| | - Yoshihiko Togawa
- Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuencho, Sakai, Osaka 599-8531, Japan
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Murooka R, Leonov AO, Inoue K, Ohe JI. Current-induced shuttlecock-like movement of non-axisymmetric chiral skyrmions. Sci Rep 2020; 10:396. [PMID: 31941954 PMCID: PMC6962387 DOI: 10.1038/s41598-019-56791-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 10/17/2019] [Indexed: 11/09/2022] Open
Abstract
Current-induced motion of non-axisymmetric skyrmions within tilted ferromagnetic phases of polar helimagnets with the easy plane anisotropy is studied by micromagnetic simulations. Such non-axisymmetric skyrmions consist of a circular core and a crescent-shaped domain-wall region formed with respect to the tilted surrounding state. Current-driven motion of non-axisymmetric skyrmions exhibits two distinct time regimes: initially the skyrmions rotate towards the current flow direction and subsequently move along the current with the skyrmionic crescent first. According to the Thiele equation, the asymmetric distribution of the topological charge and the dissipative force tensor play an important role for giving the different velocities for the circular and the crescent-shaped constituent parts of the skyrmion what underlies such a shuttlecock-like movement. Moreover, the current-velocity relation depends on the angle of the tilted ferromagnetic phase what makes in particular the transverse velocity of skyrmions sensitive to their field-driven configurational transformation. We also argue the possibility of magnetic racetrack waveguides based on complex interplay of robust asymmetric skyrmions with multiple twisted edge states.
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Affiliation(s)
- Remi Murooka
- Department of Physics, Toho University, 2-2-1 Miyama, Funabashi, Chiba, Japan
| | - Andrey O Leonov
- Chirality Research Center, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8526, Japan. .,Department of Chemistry, Faculty of Science, Hiroshima University Kagamiyama, Higashi Hiroshima, Hiroshima, 739-8526, Japan. .,IFW Dresden, Postfach 270016, D-01171, Dresden, Germany.
| | - Katsuya Inoue
- Chirality Research Center, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8526, Japan. .,Department of Chemistry, Faculty of Science, Hiroshima University Kagamiyama, Higashi Hiroshima, Hiroshima, 739-8526, Japan.
| | - Jun-Ichiro Ohe
- Department of Physics, Toho University, 2-2-1 Miyama, Funabashi, Chiba, Japan.
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Ohe JI, Takeuchi A, Tatara G. Charge current driven by spin dynamics in disordered Rashba spin-orbit system. Phys Rev Lett 2007; 99:266603. [PMID: 18233596 DOI: 10.1103/physrevlett.99.266603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Indexed: 05/25/2023]
Abstract
Pumping of charge current by spin dynamics in the presence of the Rashba spin-orbit interaction is theoretically studied. Considering a disordered electron, the exchange coupling and spin-orbit interactions are treated perturbatively. It is found that the dominant current induced by spin dynamics is interpreted as a consequence of the conversion from spin current via the inverse spin Hall effect. We also find that the current has an additional component from a fictitious conservative field. The results are applied to the case of a moving domain wall.
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Affiliation(s)
- Jun-Ichiro Ohe
- I. Institut für Theoretische Physik, Universtität Hamburg, Jungiusstrasse 9, 20355 Hamburg, Germany
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