Inter-magnet pumping counters dissipation in artificial ferrimagnets

Nature Physics (2026)Cite this article Generating a spin current naturally increases the magnetic dissipation of its source, and this unavoidable rise in dissipation presents a substantial obstacle to achieving high-efficiency and low-loss spintronics applications. Despite substantial efforts to reduce dissipation, its positive correlation with spin current output remains an insurmountable barrier. Here we demonstrate a counterintuitive phenomenon: the effective damping of an artificial ferrimagnet, which quantifies the dissipation in its dynamics, is negatively correlated with the spin current output. In other words, higher output equals lower dissipation. To explain this unexpected result, we propose a complex mechanism in which inter-magnet pumping can counter dissipation in the presence of spin current output, transforming the usual increase in dissipation into a decrease. Along with this, we observe an improvement in spin current output efficiency, quantified through the effective spin-mixing conductance. These findings revise the current understanding of spin dynamics and could provide insights useful for developing high-efficiency, low-loss spintronic devices.This is a preview of subscription content, access via your institution Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription $32.99 / 30 days cancel any timeSubscribe to this journal Receive 12 print issues and online access $259.00 per yearonly $21.58 per issueBuy this articleUSD 39.95Prices may be subject to local taxes which are calculated during checkoutThe data used in this paper are available via figshare at https://doi.org/10.6084/m9.figshare.31769101.v1 (ref. 44). Source data are provided with this paper. Additional data are available from the corresponding authors on request.Tafoya, S., Large, S. 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This work is supported by the National Key Research and Development Program of China (number 2022YFA1405100, to J.L.), the National Natural Science Foundation of China (numbers 11874072 (to J.L.), 12374130 (to Y.M.) and 11974408 (to H.-W.Z.)) the Research Council of Norway through its Centres of Excellence funding scheme (No. 262633, “QuSpin”, to A.B.) and the Strategic Priority Research Program of the Chinese Academy of Sciences (number XDB33020300, to H.-W.Z.).These authors contributed equally: Kai Zhang, Y. X. Niu.International Center for Quantum Materials, School of Physics, Peking University, Beijing, ChinaKai Zhang, Y. X. Niu, Tianxu Zhang & J. LiBeijing Key Laboratory of Quantum Devices, Peking University, Beijing, ChinaY. X. Niu, Tianxu Zhang & J. LiDepartment of Physics, University of Science and Technology of China, Hefei, ChinaPeng-Lu Zhao & Qian NiuBeijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, ChinaYang Meng & Hong-Wu ZhaoSchool of Physical Sciences, University of Chinese Academy of Sciences, Beijing, ChinaYang Meng & Hong-Wu ZhaoDepartment of Physics, Technical University of Munich, Munich, GermanyL. Chen & C. H. BackSongshan Lake Materials Laboratory, Dongguan, ChinaHong-Wu ZhaoMunich Center for Quantum Science and Technology, Munich, GermanyC. H. BackCenter for Quantum Engineering, Technical University of Munich, Munich, GermanyC. H. BackCenter for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, Trondheim, NorwayArne BrataasSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarK.Z. and Y.X.N. conducted the static and dynamic measurements. P.-L.Z. helped with the theoretical analysis. T.Z. helped with the dynamic measurements. Y.M. grew the samples and contributed to the writing of the manuscript. H.-W.Z. helped with the sample growth and participated in the discussion. C.H.B. and L.C. participated in the discussion and contributed to the revision of the manuscript. A.B. contributed to the modification of the theoretical analysis and the writing. Q.N. contributed to the theoretical analysis and the writing. J.L. designed the experiments, analysed the data, contributed to the theoretical analysis and wrote the paper.Correspondence to Yang Meng, Arne Brataas, Qian Niu or J. Li.The authors declare no competing interests.Nature Physics thanks Andrew Kent and Prasanta Muduli for their contribution to the peer review of this work.Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.a,b, The FMR spectra of FiM/Cu/Pt and FiM/Cu samples at T = 20 K (a) and T = 150 K (b). c,d, The FMR-induced voltage (V) is measured in the FiM/Cu/Pt at T = 20 K (c) and T = 150 K (d).Source dataa,b, Illustration of spin pumping measurements. The azimuthal directions of H (θH) and M equilibrium (θM) define the experimental geometry. c, Angular dependence of \({V}_{{\rm{sym}}}\) and \({V}_{{\rm{asym}}}\) at T = 10 K (f = 11 GHz). d, The normalized \({V}_{{\rm{sym}}}\) signal \({\widetilde{V}}_{{\rm{sym}}}\) at T = 10 K with f = 9 GHz, f = 10 GHz and f = 11 GHz.Source dataa to c plot the full \(V\left(H\right)\) spectrum as a function of f at T = 10 K, T = 30 K, and T = 50 K. As the twisted mode (LH) approaches the FMR mode (RH), the hybridization of two chiral modes transforms the FMR mode to a linearly polarized precession mode at T = 50 K. The linearly polarized mode carries no angular momentum, leading to the absence of a spin-pumping effect.Supplementary Figs. 1–9 and Sections 1–9.Source data for the determination of the damping parameter.Source data for the damping parameter and normalized spin-pumping voltage.Source data for the damping parameters determined in the calculations compared with the experimental values.Source data for the FMR spectra and FMR-induced voltage.Source data for the field-angle-dependent spin-pumping measurements.Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.Reprints and permissionsZhang, K., Niu, Y.X., Zhao, PL. et al. Inter-magnet pumping counters dissipation in artificial ferrimagnets. Nat. Phys. (2026). https://doi.org/10.1038/s41567-026-03261-zDownload citationReceived: 28 August 2025Accepted: 23 March 2026Published: 17 April 2026Version of record: 17 April 2026DOI: https://doi.org/10.1038/s41567-026-03261-zAnyone you share the following link with will be able to read this content:Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative