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Ishito K, Mao H, Kobayashi K, Kousaka Y, Togawa Y, Kusunose H, Kishine JI, Satoh T. Chiral phonons: circularly polarized Raman spectroscopy and ab initio calculations in a chiral crystal tellurium. Chirality 2023; 35:338-345. [PMID: 36891931 DOI: 10.1002/chir.23544] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/22/2023] [Accepted: 01/26/2023] [Indexed: 03/10/2023]
Abstract
Recently, phonons with chirality (chiral phonons) have attracted significant attention. Chiral phonons exhibit angular and pseudoangular momenta. In circularly polarized Raman spectroscopy, the peak split of the Γ 3 $$ {\Gamma}_3 $$ mode is detectable along the principal axis of the chiral crystal in the backscattering configuration. In addition, peak splitting occurs when the pseudoangular momenta of the incident and scattered circularly polarized light are reversed. Until now, chiral phonons in binary crystals have been observed, whereas those in unary crystals have not been observed. Here, we observe chiral phonons in a chiral unary crystal Te. The pseudoangular momentum of the phonon is obtained in Te by an ab initio calculation. From this calculation, we verified the conservation law of pseudoangular momentum in Raman scattering. From this conservation law, we determined the handedness of the chiral crystals. We also evaluated the true chirality of the phonons using a measure with symmetry similar to that of an electric toroidal monopole.
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Affiliation(s)
- Kyosuke Ishito
- Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
| | - Huiling Mao
- Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
| | - Kaya Kobayashi
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, Japan
| | - Yusuke Kousaka
- Department of Physics and Electronics, Osaka Metropolitan University, Osaka, Japan
| | - Yoshihiko Togawa
- Department of Physics and Electronics, Osaka Metropolitan University, Osaka, Japan
| | | | - Jun-Ichiro Kishine
- Division of Natural and Environmental Sciences, The Open University of Japan, Chiba, Japan
| | - Takuya Satoh
- Department of Physics, Tokyo Institute of Technology, Tokyo, 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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Proskurin I, Stamps RL, Ovchinnikov AS, Kishine JI. Spin-Wave Chirality and Its Manifestations in Antiferromagnets. Phys Rev Lett 2017; 119:177202. [PMID: 29219475 DOI: 10.1103/physrevlett.119.177202] [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: 05/31/2017] [Indexed: 06/07/2023]
Abstract
As first demonstrated by Tang and Cohen in chiral optics, the asymmetry in the rate of electromagnetic energy absorption between left and right enantiomers is determined by an optical chirality density. Here, we demonstrate that this effect can exist in magnetic spin systems. By constructing a formal analogy with electrodynamics, we show that in antiferromagnets with broken chiral symmetry, the asymmetry in local spin-wave energy absorption is proportional to a spin-wave chirality density, which is a direct counterpart of optical zilch. We propose that injection of a pure spin current into an antiferromagnet may serve as a chiral symmetry breaking mechanism, since its effect in the spin-wave approximation can be expressed in terms of additional Lifshitz invariants. We use linear response theory to show that the spin current induces a nonequilibrium spin-wave chirality density.
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Affiliation(s)
- Igor Proskurin
- Division of Natural and Environmental Sciences, The Open University of Japan, Chiba 261-8586, Japan
- Institute of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg 620002, Russia
| | - Robert L Stamps
- Department of Physics and Astronomy, University of Manitoba, Winnipeg MB R3T 2N2, Canada
| | - Alexander S Ovchinnikov
- Institute of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg 620002, Russia
- Institute for Metal Physics, RAS, Ekaterinburg 620137, Russia
| | - Jun-Ichiro Kishine
- Division of Natural and Environmental Sciences, The Open University of Japan, Chiba 261-8586, Japan
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