المؤلفون: Liu, Jiuming, Liao, Liyang, Rong, Bin, Wu, Yuyang, Zhang, Yu, Ruan, Hanzhi, Zhi, Zhenghang, Huang, Puyang, Yao, Shan, Cai, Xinyu, Tang, Chenjia, Yao, Qi, Sun, Lu, Yang, Yumeng, Yu, Guoqiang, Che, Renchao, Kou, Xufeng

مصطلحات موضوعية: Physics - Applied Physics

الوصف: Magnetoresistance effects are crucial for understanding the charge/spin transport as well as propelling the advancement of spintronic applications. Here we report the coexistence of magnetic moment-dependent (MD) and magnetic field-driven (FD) unidirectional magnetoresistance (UMR) effects in CoFeB/InSb/CdTe heterostructures. The strong spin-orbital coupling of InSb and the matched impedance at the CoFeB/InSb interface warrant a distinct MD-UMR effect at room temperature, while the interaction between the in-plane magnetic field and the Rashba effect at the InSb/CdTe interface induces the marked FD-UMR signal that dominates the high-field region. Moreover, owning to the different spin transport mechanisms, these two types of nonreciprocal charge transport show opposite polarities with respect to the magnetic field direction, which further enable an effective phase modulation of the angular-dependent magnetoresistance. Besides, the demonstrations of both the tunable UMR response and two-terminal spin-orbit torque-driven magnetization switching validate our CoFeB/InSb/CdTe system as a suitable integrated building block for multifunctional spintronic device design.

الوصول الحر: http://arxiv.org/abs/2311.11843Test

المؤلفون: Huang, Lin, Liao, Liyang, Qiu, Hongsong, Chen, Xianzhe, Bai, Hua, Han, Lei, Zhou, Yongjian, Su, Yichen, Zhou, Zhiyuan, Pan, Feng, Jin, Biaobing, Song, Cheng

مصطلحات موضوعية: Condensed Matter - Materials Science

الوصف: N\'eel spin-orbit torque allows a charge current pulse to efficiently manipulate the N\'eel vector in antiferromagnets, which offers a unique opportunity for ultrahigh density information storage with high speed. However, the reciprocal process of N\'eel spin-orbit torque, the generation of ultrafast charge current in antiferromagnets has not been demonstrated. Here, we report the experimental observation of charge current generation in antiferromagnetic metallic Mn2Au thin films using ultrafast optical excitation. The ultrafast laser pulse excites antiferromagnetic magnons, resulting in instantaneous non-equilibrium spin polarization at the antiferromagnetic spin sublattices with broken spatial symmetry. Then the charge current is generated directly via spin-orbit fields at the two sublattices, which is termed as the reciprocal phenomenon of N\'eel spin-orbit torque, and the associated THz emission can be detected at room temperature. Besides the fundamental significance on the Onsager reciprocity, the observed magnonic charge current generation in antiferromagnet would advance the development of antiferromagnetic THz emitter.
Comment: 15 pages, 4 figures, this work was submitted to Nature Communications on Jan. 4th, 2023, now is under the 3rd review process

الوصول الحر: http://arxiv.org/abs/2310.03987Test

المؤلفون: Hwang, Yunyoung, Puebla, Jorge, Kondou, Kouta, Gonzalez-Ballestero, Carlos, Isshiki, Hironari, Muñoz, Carlos Sánchez, Liao, Liyang, Chen, Fa, Luo, Wei, Maekawa, Sadamichi, Otani, Yoshichika

مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics

الوصف: Here, we report the observation of strong coupling between magnons and surface acoustic wave (SAW) phonons in a thin CoFeB film constructed in an on-chip SAW resonator by analyzing SAW phonon dispersion anticrossings. Our device design provides the tunability of the film thickness with a fixed phonon wavelength, which is a departure from the conventional approach in strong magnon--phonon coupling research. We detect a monotonic increase in the coupling strength by expanding the film thickness, which agrees with our theoretical model. Our work offers a significant way to advance fundamental research and the development of devices based on magnon--phonon hybrid quasiparticles.
Comment: Main text 6 pages, 4 figures, plus supplemental materials

الوصول الحر: http://arxiv.org/abs/2309.12690Test

المؤلفون: Liao, Liyang, Puebla, Jorge, Yamamoto, Kei, Kim, Junyeon, Meakawa, Sadamichi, Hwang, Yunyoung, Ba, You, Otani, Yoshichika

مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics

الوصف: Phonons and magnons are engineered by periodic potential landscapes in phononic and magnonic crystals, and their combined studies may enable valley phonon transport tunable by the magnetic field. Through nonreciprocal surface acoustic wave transmission, we demonstrate valley-selective phonon-magnon scattering in magnetoelastic superlattices. The lattice symmetry and the out-of-plane magnetization component control the sign of nonreciprocity. The phonons in the valleys play a crucial role in generating nonreciprocal transmission by inducing circularly polarized strains that couple with the magnons. The transmission spectra show a nonreciprocity peak near a transmission gap, matching the phononic band structure. Our results open the way for manipulating valley phonon transport through periodically varying magnon-phonon coupling.

الوصول الحر: http://arxiv.org/abs/2307.03367Test

المؤلفون: Liu, Xinqi, Xia, Yunyouyou, Gao, Lei, Huang, Puyang, Liao, Liyang, Cui, Baoshan, Backes, Dirk, van der Laan, Gerrit, Hesjedal, Thorsten, Ji, Yuchen, Chen, Peng, Wu, Fan, Wang, Meixiao, Zhang, Junwei, Yu, Guoqiang, Song, Cheng, Chen, Yulin, Liu, Zhongkai, Yang, Yumeng, Peng, Yong, Li, Gang, Yao, Qi, Kou, Xufeng

مصطلحات موضوعية: Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics

الوصف: To harness the intriguing properties of two-dimensional van der Waals (vdW) ferromagnets (FMs) for versatile applications, the key challenge lies in the reliable material synthesis for scalable device production. Here, we demonstrate the epitaxial growth of single-crystalline 1T-CrTe2 thin films on 2-inch sapphire substrates. Benefiting from the uniform surface energy of the dangling bond-free Al2O3(0001) surface, the layer-by-layer vdW growth mode is observed right from the initial growth stage, which warrants precise control of the sample thickness and atomically smooth surface morphology across the entire wafer. Moreover, the presence of the Coulomb interaction at the CrTe2/Al2O3 interface serves as an effective tuning parameter to tailor the anomalous Hall response, and the structural optimization of the CrTe2-based spin-orbit torque device leads to a substantial switching power reduction by 54%. Our results may lay out a general framework for the design of energy-efficient spintronics based on configurable vdW FMs.
Comment: 20 pages, 4 figures

الوصول الحر: http://arxiv.org/abs/2207.05944Test

المؤلفون: Zhou, Yongjian, Liao, Liyang, Zhou, Xiaofeng, Bai, Hua, Zhao, Mingkun, Wan, Caihua, Yin, Siqi, Huang, Lin, Guo, Tingwen, Han, Lei, Chen, Ruyi, Zhou, Zhiyuan, Han, Xiufeng, Pan, Feng, Song, Cheng

مصطلحات موضوعية: Condensed Matter - Materials Science

الوصف: The interlayer coupling mediated by fermions in ferromagnets brings about parallel and anti-parallel magnetization orientations of two magnetic layers, resulting in the giant magnetoresistance, which forms the foundation in spintronics and accelerates the development of information technology. However, the interlayer coupling mediated by another kind of quasi-particle, boson, is still lacking. Here we demonstrate such a static interlayer coupling at room temperature in an antiferromagnetic junction Fe2O3/Cr2O3/Fe2O3, where the two antiferromagnetic Fe2O3 layers are functional materials and the antiferromagnetic Cr2O3 layer serves as a spacer. The N\'eel vectors in the top and bottom Fe2O3 are strongly orthogonally coupled, which is bridged by a typical bosonic excitation (magnon) in the Cr2O3 spacer. Such an orthogonally coupling exceeds the category of traditional collinear interlayer coupling via fermions in ground state, reflecting the fluctuating nature of the magnons, as supported by our magnon quantum well model. Besides the fundamental significance on the quasi-particle-mediated interaction, the strong coupling in an antiferromagnetic magnon junction makes it a realistic candidate for practical antiferromagnetic spintronics and magnonics with ultrahigh-density integration.
Comment: 19 pages, 4 figures

الوصول الحر: http://arxiv.org/abs/2101.08665Test

المؤلفون: Chen, Peng, Zhang, Yong, Yao, Qi, Tian, Fugu, Li, Lun, Qi, Zhengkun, Liu, Xiaoyang, Liao, Liyang, Song, Cheng, Wang, Jingyuan, Xia, Jing, Li, Gang, Burn, David M., van der Laan, Gerrit, Hesjedal, Thorsten, Zhang, Shilei, Kou, Xufeng

مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science

الوصف: Engineering the anomalous Hall effect (AHE) in the emerging magnetic topological insulators (MTIs) has great potentials for quantum information processing and spintronics applications. In this letter, we synthesize the epitaxial Bi2Te3/MnTe magnetic heterostructures and observe pronounced AHE signals from both layers combined together. The evolution of the resulting hybrid AHE intensity with the top Bi2Te3 layer thickness manifests the presence of an intrinsic ferromagnetic phase induced by the topological surface states at the heterolayer-interface. More importantly, by doping the Bi2Te3 layer with Sb, we are able to manipulate the sign of the Berry phase-associated AHE component. Our results demonstrate the un-paralleled advantages of MTI heterostructures over magnetically doped TI counterparts, in which the tunability of the AHE response can be greatly enhanced. This in turn unveils a new avenue for MTI heterostructure-based multifunctional applications.
Comment: 20 pages, 4 figures

الوصول الحر: http://arxiv.org/abs/1912.07157Test

المؤلفون: Hwang, Yunyoung, Puebla, Jorge, Kondou, Kouta, Gonzalez-Ballestero, Carlos, Isshiki, Hironari, Muñoz, Carlos Sánchez, Liao, Liyang, Chen, Fa, Luo, Wei, Maekawa, Sadamichi, Otani, Yoshichika

المساهمون: Japan Society for the Promotion of Science, RIKEN, National Key Research and Development Program of China, Université Grenoble Alpes

المصدر: Physical Review Letters ; volume 132, issue 5 ; ISSN 0031-9007 1079-7114

الإتاحة: https://doi.org/10.1103/physrevlett.132.056704Test

المؤلفون: Zhou, Yongjian, Guo, Tingwen, Han, Lei, Liao, Liyang, He, Wenqing, Wan, Caihua, Chen, Chong, Wang, Qian, Qiao, Leilei, Bai, Hua, Zhu, Wenxuan, Zhang, Yichi, Chen, Ruyi, Han, Xiufeng, Pan, Feng, Song, Cheng

المصدر: Science Advances ; volume 10, issue 2 ; ISSN 2375-2548

الوصف: The intrinsic fast dynamics make antiferromagnetic spintronics a promising avenue for faster data processing. Ultrafast antiferromagnetic resonance–generated spin current provides valuable access to antiferromagnetic spin dynamics. However, the inverse effect, spin-torque–driven antiferromagnetic resonance (ST-AFMR), which is attractive for practical utilization of fast devices but seriously impeded by difficulties in controlling and detecting Néel vectors, remains elusive. We observe ST-AFMR in Y 3 Fe 5 O 12 /α-Fe 2 O 3 /Pt at room temperature. The Néel vector oscillates and contributes to voltage signal owing to antiferromagnetic negative spin Hall magnetoresistance–induced spin rectification effect, which has the opposite sign to ferromagnets. The Néel vector in antiferromagnetic α-Fe 2 O 3 is strongly coupled to the magnetization in Y 3 Fe 5 O 12 buffer, resulting in the convenient control of Néel vectors. ST-AFMR experiment is bolstered by micromagnetic simulations, where both the Néel vector and the canted moment of α-Fe 2 O 3 are in elliptic resonance. These findings shed light on the spin current–induced dynamics in antiferromagnets and represent a step toward electrically controlled antiferromagnetic terahertz emitters.

الإتاحة: https://doi.org/10.1126/sciadv.adk7935Test

المؤلفون: Zhou, Yongjian, Liao, Liyang, Guo, Tingwen, Bai, Hua, Zhao, Mingkun, Wan, Caihua, Huang, Lin, Han, Lei, Qiao, Leilei, You, Yunfeng, Chen, Chong, Chen, Ruyi, Zhou, Zhiyuan, Han, Xiufeng, Pan, Feng, Song, Cheng

المساهمون: National Natural Science Foundation of China

المصدر: Nature Communications ; volume 13, issue 1 ; ISSN 2041-1723

مصطلحات موضوعية: General Physics and Astronomy, General Biochemistry, Genetics and Molecular Biology, General Chemistry, Multidisciplinary

الوصف: In conventional ferromagnet/spacer/ferromagnet sandwiches, noncollinear couplings are commonly absent because of the low coupling energy and strong magnetization. For antiferromagnets (AFM), the small net moment can embody a low coupling energy as a sizable coupling field, however, such AFM sandwich structures have been scarcely explored. Here we demonstrate orthogonal interlayer coupling at room temperature in an all-antiferromagnetic junction Fe 2 O 3 /Cr 2 O 3 /Fe 2 O 3 , where the Néel vectors in the top and bottom Fe 2 O 3 layers are strongly orthogonally coupled and the coupling strength is significantly affected by the thickness of the antiferromagnetic Cr 2 O 3 spacer. From the energy and symmetry analysis, the direct coupling via uniform magnetic ordering in Cr 2 O 3 spacer in our junction is excluded. The coupling is proposed to be mediated by the non-uniform domain wall state in the spacer. The strong long-range coupling in an antiferromagnetic junction provides an unexplored approach for designing antiferromagnetic structures and makes it a promising building block for antiferromagnetic devices.

الإتاحة: https://doi.org/10.1038/s41467-022-31531-wTest
https://www.nature.com/articles/s41467-022-31531-w.pdfTest
https://www.nature.com/articles/s41467-022-31531-wTest