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Do Bang - One of the best experts on this subject based on the ideXlab platform.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
Nature Materials, 2019Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Spintronics relies on magnetization switching through current-induced spin torques. However, because spin transfer torque for ferromagnets is a surface torque, a large switching current is required for a thick, thermally stable ferromagnetic cell, and this remains a fundamental obstacle for high-density non-volatile applications with ferromagnets. Here, we report a long spin coherence length and associated bulk-like torque characteristics in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through >10-nm-thick Ferrimagnetic Co/Tb multilayers, whereas it is entirely absorbed by a 1-nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like torque characteristic, as it increases with ferrimagnet thickness up to 8 nm and then decreases, in clear contrast to the 1/thickness dependence of ferromagnetic Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate research towards the development of energy-efficient spintronics.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
arXiv: Materials Science, 2018Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Ferromagnetic spintronics has been a main focus as it offers non-volatile memory and logic applications through current-induced spin-transfer torques. Enabling wider applications of such magnetic devices requires a lower switching current for a smaller cell while keeping the thermal stability of magnetic cells for non-volatility. As the cell size reduces, however, it becomes extremely difficult to meet this requirement with ferromagnets because spin-transfer torque for ferromagnets is a surface torque due to rapid spin dephasing, leading to the 1/ferromagnet-thickness dependence of the spin-torque efficiency. Requirement of a larger switching current for a thicker and thus more thermally stable ferromagnetic cell is the fundamental obstacle for high-density non-volatile applications with ferromagnets. Theories predicted that antiferromagnets have a long spin coherence length due to the staggered spin order on an atomic scale, thereby resolving the above fundamental limitation. Despite several spin-torque experiments on antiferromagnets and Ferrimagnetic alloys, this prediction has remained unexplored. Here we report a long spin coherence length and associated bulk-like-torque characteristic in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through > 10 nm-thick Ferrimagnetic Co/Tb multilayers whereas it is entirely absorbed by 1 nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like-torque characteristic as it increases with the ferrimagnet-thickness up to 8 nm and then decreases, in clear contrast to 1/thickness-dependence of Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate researches towards energy-efficient spintronic technologies.
Seo Won Lee - One of the best experts on this subject based on the ideXlab platform.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
Nature Materials, 2019Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Spintronics relies on magnetization switching through current-induced spin torques. However, because spin transfer torque for ferromagnets is a surface torque, a large switching current is required for a thick, thermally stable ferromagnetic cell, and this remains a fundamental obstacle for high-density non-volatile applications with ferromagnets. Here, we report a long spin coherence length and associated bulk-like torque characteristics in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through >10-nm-thick Ferrimagnetic Co/Tb multilayers, whereas it is entirely absorbed by a 1-nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like torque characteristic, as it increases with ferrimagnet thickness up to 8 nm and then decreases, in clear contrast to the 1/thickness dependence of ferromagnetic Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate research towards the development of energy-efficient spintronics.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
arXiv: Materials Science, 2018Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Ferromagnetic spintronics has been a main focus as it offers non-volatile memory and logic applications through current-induced spin-transfer torques. Enabling wider applications of such magnetic devices requires a lower switching current for a smaller cell while keeping the thermal stability of magnetic cells for non-volatility. As the cell size reduces, however, it becomes extremely difficult to meet this requirement with ferromagnets because spin-transfer torque for ferromagnets is a surface torque due to rapid spin dephasing, leading to the 1/ferromagnet-thickness dependence of the spin-torque efficiency. Requirement of a larger switching current for a thicker and thus more thermally stable ferromagnetic cell is the fundamental obstacle for high-density non-volatile applications with ferromagnets. Theories predicted that antiferromagnets have a long spin coherence length due to the staggered spin order on an atomic scale, thereby resolving the above fundamental limitation. Despite several spin-torque experiments on antiferromagnets and Ferrimagnetic alloys, this prediction has remained unexplored. Here we report a long spin coherence length and associated bulk-like-torque characteristic in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through > 10 nm-thick Ferrimagnetic Co/Tb multilayers whereas it is entirely absorbed by 1 nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like-torque characteristic as it increases with the ferrimagnet-thickness up to 8 nm and then decreases, in clear contrast to 1/thickness-dependence of Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate researches towards energy-efficient spintronic technologies.
Pham Van Thach - One of the best experts on this subject based on the ideXlab platform.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
Nature Materials, 2019Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Spintronics relies on magnetization switching through current-induced spin torques. However, because spin transfer torque for ferromagnets is a surface torque, a large switching current is required for a thick, thermally stable ferromagnetic cell, and this remains a fundamental obstacle for high-density non-volatile applications with ferromagnets. Here, we report a long spin coherence length and associated bulk-like torque characteristics in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through >10-nm-thick Ferrimagnetic Co/Tb multilayers, whereas it is entirely absorbed by a 1-nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like torque characteristic, as it increases with ferrimagnet thickness up to 8 nm and then decreases, in clear contrast to the 1/thickness dependence of ferromagnetic Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate research towards the development of energy-efficient spintronics.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
arXiv: Materials Science, 2018Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Ferromagnetic spintronics has been a main focus as it offers non-volatile memory and logic applications through current-induced spin-transfer torques. Enabling wider applications of such magnetic devices requires a lower switching current for a smaller cell while keeping the thermal stability of magnetic cells for non-volatility. As the cell size reduces, however, it becomes extremely difficult to meet this requirement with ferromagnets because spin-transfer torque for ferromagnets is a surface torque due to rapid spin dephasing, leading to the 1/ferromagnet-thickness dependence of the spin-torque efficiency. Requirement of a larger switching current for a thicker and thus more thermally stable ferromagnetic cell is the fundamental obstacle for high-density non-volatile applications with ferromagnets. Theories predicted that antiferromagnets have a long spin coherence length due to the staggered spin order on an atomic scale, thereby resolving the above fundamental limitation. Despite several spin-torque experiments on antiferromagnets and Ferrimagnetic alloys, this prediction has remained unexplored. Here we report a long spin coherence length and associated bulk-like-torque characteristic in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through > 10 nm-thick Ferrimagnetic Co/Tb multilayers whereas it is entirely absorbed by 1 nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like-torque characteristic as it increases with the ferrimagnet-thickness up to 8 nm and then decreases, in clear contrast to 1/thickness-dependence of Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate researches towards energy-efficient spintronic technologies.
Gerrit E W Bauer - One of the best experts on this subject based on the ideXlab platform.
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thermal control of the magnon photon coupling in a notch filter coupled to a yttrium iron garnet platinum system
Physical Review B, 2017Co-Authors: Vincent Castel, Rodolphe Jeunehomme, Jamal Ben Youssef, N Vukadinovic, Alexandre Manchec, Fasil Kidane Dejene, Gerrit E W BauerAbstract:We report thermal control of mode hybridization between the ferromagnetic resonance and a planar resonator (notch filter) working at 4.74 GHz. The chosen magnetic material is a Ferrimagnetic insulator (yttrium iron garnet: YIG) covered by 6 nm of platinum (Pt). A current-induced heating method has been used in order to enhance the temperature of the YIG/Pt system. The device permits us to control the transmission spectra and the magnon-photon coupling strength at room temperature. These experimental findings reveal a potentially applicable tunable microwave filtering function.
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Thermal control of the magnon-photon coupling in a notch filter coupled to a yttrium iron garnet/platinum system
Physical Review B: Condensed Matter and Materials Physics, 2017Co-Authors: Vincent Castel, Rodolphe Jeunehomme, N Vukadinovic, Alexandre Manchec, Jamal Ben Youssef, Fasil Kidane Dejene, Gerrit E W BauerAbstract:We report thermal control of mode hybridization between the ferromagnetic resonance and a planar resonator (notch filter) working at 4.74 GHz. The chosen magnetic material is a Ferrimagnetic insulator (yttrium iron garnet: YIG) covered by 6 nm of platinum (Pt). A current-induced heating method has been used in order to enhance the temperature of the YIG/Pt system. The device permits us to control the transmission spectra and the magnon-photon coupling strength at room temperature. These experimental findings reveal a potentially applicable tunable microwave filtering function.
Dong Kyu Lee - One of the best experts on this subject based on the ideXlab platform.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
Nature Materials, 2019Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Spintronics relies on magnetization switching through current-induced spin torques. However, because spin transfer torque for ferromagnets is a surface torque, a large switching current is required for a thick, thermally stable ferromagnetic cell, and this remains a fundamental obstacle for high-density non-volatile applications with ferromagnets. Here, we report a long spin coherence length and associated bulk-like torque characteristics in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through >10-nm-thick Ferrimagnetic Co/Tb multilayers, whereas it is entirely absorbed by a 1-nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like torque characteristic, as it increases with ferrimagnet thickness up to 8 nm and then decreases, in clear contrast to the 1/thickness dependence of ferromagnetic Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate research towards the development of energy-efficient spintronics.
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long spin coherence length and bulk like spin orbit torque in Ferrimagnetic multilayers
arXiv: Materials Science, 2018Co-Authors: Do Bang, Rahul Mishra, Rajagopalan Ramaswamy, Hyeon Jong Park, Yunboo Jeong, Pham Van Thach, Dong Kyu Lee, Seo Won LeeAbstract:Ferromagnetic spintronics has been a main focus as it offers non-volatile memory and logic applications through current-induced spin-transfer torques. Enabling wider applications of such magnetic devices requires a lower switching current for a smaller cell while keeping the thermal stability of magnetic cells for non-volatility. As the cell size reduces, however, it becomes extremely difficult to meet this requirement with ferromagnets because spin-transfer torque for ferromagnets is a surface torque due to rapid spin dephasing, leading to the 1/ferromagnet-thickness dependence of the spin-torque efficiency. Requirement of a larger switching current for a thicker and thus more thermally stable ferromagnetic cell is the fundamental obstacle for high-density non-volatile applications with ferromagnets. Theories predicted that antiferromagnets have a long spin coherence length due to the staggered spin order on an atomic scale, thereby resolving the above fundamental limitation. Despite several spin-torque experiments on antiferromagnets and Ferrimagnetic alloys, this prediction has remained unexplored. Here we report a long spin coherence length and associated bulk-like-torque characteristic in an antiferromagnetically coupled Ferrimagnetic multilayer. We find that a transverse spin current can pass through > 10 nm-thick Ferrimagnetic Co/Tb multilayers whereas it is entirely absorbed by 1 nm-thick ferromagnetic Co/Ni multilayer. We also find that the switching efficiency of Co/Tb multilayers partially reflects a bulk-like-torque characteristic as it increases with the ferrimagnet-thickness up to 8 nm and then decreases, in clear contrast to 1/thickness-dependence of Co/Ni multilayers. Our results on antiferromagnetically coupled systems will invigorate researches towards energy-efficient spintronic technologies.
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coherent terahertz spin wave emission associated with Ferrimagnetic domain wall dynamics
Physical Review B, 2017Co-Authors: Se Kwon Kim, Dong Kyu Lee, Kabjin Kim, Teruo Ono, Yaroslav Tserkovnyak, Kyungjin LeeAbstract:We theoretically study the dynamics of Ferrimagnetic domain walls in the presence of Dzyaloshinskii-Moriya interaction. We find that an application of a DC magnetic field can induce terahertz spin-wave emission by driving Ferrimagnetic domain walls, which is not possible for ferromagnetic or antiferromagnetic domain walls. Dzyaloshinskii-Moriya interaction is shown to facilitate the teraherz spin-wave emission in wide ranges of net angular momentum by increasing the Walkerbreakdown field. Moreover, we show that spin-orbit torque combined with Dzyaloshinskii-Moriya interaction also drives a fast Ferrimagnetic domain wall motion with emitting terahertz spin-waves in wide ranges of net angular momentum.