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Sharma R, Mishra R, Ngo T, Guo YX, Fukami S, Sato H, Ohno H, Yang H. Electrically connected spin-torque oscillators array for 2.4 GHz WiFi band transmission and energy harvesting. Nat Commun 2021; 12:2924. [PMID: 34006830 PMCID: PMC8131736 DOI: 10.1038/s41467-021-23181-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 04/20/2021] [Indexed: 12/28/2022] Open
Abstract
The mutual synchronization of spin-torque oscillators (STOs) is critical for communication, energy harvesting and neuromorphic applications. Short range magnetic coupling-based synchronization has spatial restrictions (few µm), whereas the long-range electrical synchronization using vortex STOs has limited frequency responses in hundreds MHz (<500 MHz), restricting them for on-chip GHz-range applications. Here, we demonstrate electrical synchronization of four non-vortex uniformly-magnetized STOs using a single common current source in both parallel and series configurations at 2.4 GHz band, resolving the frequency-area quandary for designing STO based on-chip communication systems. Under injection locking, synchronized STOs demonstrate an excellent time-domain stability and substantially improved phase noise performance. By integrating the electrically connected eight STOs, we demonstrate the battery-free energy-harvesting system by utilizing the wireless radio-frequency energy to power electronic devices such as LEDs. Our results highlight the significance of electrical topology (series vs. parallel) while designing an on-chip STOs system.
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Affiliation(s)
- Raghav Sharma
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Rahul Mishra
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
- Centre for Applied Research in Electronics, Indian Institute of Technology Delhi, New Delhi, India
| | - Tung Ngo
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Yong-Xin Guo
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Shunsuke Fukami
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Aoba, Sendai, Japan
- Center for Spintronics Research Network, Tohoku University, Aoba, Sendai, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai, Japan
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba, Sendai, Japan
| | - Hideo Sato
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Aoba, Sendai, Japan
- Center for Spintronics Research Network, Tohoku University, Aoba, Sendai, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai, Japan
| | - Hideo Ohno
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Aoba, Sendai, Japan
- Center for Science and Innovation in Spintronics, Tohoku University, Aoba, Sendai, Japan
- Center for Spintronics Research Network, Tohoku University, Aoba, Sendai, Japan
- Center for Innovative Integrated Electronic Systems, Tohoku University, Sendai, Japan
- WPI Advanced Institute for Materials Research, Tohoku University, Aoba, Sendai, Japan
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
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Skowroński W, Chęciński J, Ziętek S, Yakushiji K, Yuasa S. Microwave magnetic field modulation of spin torque oscillator based on perpendicular magnetic tunnel junctions. Sci Rep 2019; 9:19091. [PMID: 31836753 PMCID: PMC6910944 DOI: 10.1038/s41598-019-55220-9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/14/2019] [Indexed: 11/30/2022] Open
Abstract
Modulation of a microwave signal generated by the spin-torque oscillator (STO) based on a magnetic tunnel junction (MTJ) with perpendicularly magnetized free layer is investigated. Magnetic field inductive loop was created during MTJ fabrication process, which enables microwave field application during STO operation. The frequency modulation by the microwave magnetic field of up to 3 GHz is explored, showing a potential for application in high-data-rate communication technologies. Moreover, an inductive loop is used for self-synchronization of the STO signal, which after field-locking, exhibits significant improvement of the linewidth and oscillation power.
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Affiliation(s)
- Witold Skowroński
- AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059, Kraków, Poland.
| | - Jakub Chęciński
- AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059, Kraków, Poland
| | - Sławomir Ziętek
- AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059, Kraków, Poland
| | - Kay Yakushiji
- National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba, Ibaraki, 305-8568, Japan
| | - Shinji Yuasa
- National Institute of Advanced Industrial Science and Technology (AIST), Spintronics Research Center, Tsukuba, Ibaraki, 305-8568, Japan
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Houshang A, Khymyn R, Fulara H, Gangwar A, Haidar M, Etesami SR, Ferreira R, Freitas PP, Dvornik M, Dumas RK, Åkerman J. Spin transfer torque driven higher-order propagating spin waves in nano-contact magnetic tunnel junctions. Nat Commun 2018; 9:4374. [PMID: 30348986 PMCID: PMC6197248 DOI: 10.1038/s41467-018-06589-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [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: 12/06/2017] [Accepted: 09/12/2018] [Indexed: 11/08/2022] Open
Abstract
Short wavelength exchange-dominated propagating spin waves will enable magnonic devices to operate at higher frequencies and higher data transmission rates. While giant magnetoresistance (GMR)-based magnetic nanocontacts are efficient injectors of propagating spin waves, the generated wavelengths are 2.6 times the nano-contact diameter, and the electrical signal strength remains too weak for applications. Here we demonstrate nano-contact-based spin wave generation in magnetic tunnel junctions and observe large-frequency steps consistent with the hitherto ignored possibility of second- and third-order propagating spin waves with wavelengths of 120 and 74 nm, i.e., much smaller than the 150-nm nanocontact. Mutual synchronization is also observed on all three propagating modes. These higher-order propagating spin waves will enable magnonic devices to operate at much higher frequencies and greatly increase their transmission rates and spin wave propagating lengths, both proportional to the much higher group velocity.
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Affiliation(s)
- A Houshang
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
- NanOsc AB, 164 40, Kista, Sweden
| | - R Khymyn
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
| | - H Fulara
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
| | - A Gangwar
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
| | - M Haidar
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
| | - S R Etesami
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
| | - R Ferreira
- International Iberian Nanotechnology Laboratory, Braga, 4715-330, Portugal
| | - P P Freitas
- International Iberian Nanotechnology Laboratory, Braga, 4715-330, Portugal
| | - M Dvornik
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
| | - R K Dumas
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden
| | - J Åkerman
- Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden.
- NanOsc AB, 164 40, Kista, Sweden.
- Material Physics, School of Engineering Sciences, Royal Institute of Technology, Electrum 229, 164 40, Kista, Sweden.
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