{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Kurokawa Y"],"funding":["OGAWA Science and Technology Foundation","Hattori Hokokai Foundation","Japan Society for the Promotion of Science"],"pagination":["10849"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC9296563"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["12(1)"],"pubmed_abstract":["Recent increased development interest in millimeter-wave oscillator devices has necessitated realization of small oscillators with high frequency, wide frequency tunability, and room-temperature operation. Spin-torque oscillators (STOs) are fascinating candidates for such applications because of their nanometer size and suitability for room-temperature operation. However, their oscillation frequency and tunable range are limited to the order of 100 MHz-10 GHz. Here, we propose use of bilinear (J<sub>1</sub>) and biquadratic (J<sub>2</sub>) interlayer exchange couplings between ferromagnets in STOs to overcome these problems. The bilinear coupling contributes to oscillation frequency enhancement, whereas the biquadratic coupling facilitates frequency tunability via a current. Using micromagnetic simulation with parameters estimated from a material with small saturation magnetization, for J<sub>1</sub> = 0 and J<sub>2</sub> =  - 1.0 mJ/m<sup>2</sup>, respectively, we find that the STO exhibits high frequency from 23 to 576 GHz and that its tunability reaches 61 GHz/(10<sup>11</sup> A/m<sup>2</sup>) for current densities of - 0.5 to - 9.5 × 10<sup>11</sup> A/m<sup>2</sup>. An analytical theory based on the macrospin model is also developed, which exhibits good quantitative agreement with the micromagnetic simulations. These results introduce new possibilities for spintronics applications in high-frequency devices such as next-generation mobile communications."],"journal":["Scientific reports"],"pubmed_title":["Ultra-wide-band millimeter-wave generator using spin torque oscillator with strong interlayer exchange couplings."],"pmcid":["PMC9296563"],"funding_grant_id":["JP21K14487","JP20K05255"],"pubmed_authors":["Yuasa H","Horiike S","Tanaka T","Kurokawa Y","Taniguchi T","Yamada K"],"additional_accession":[]},"is_claimable":false,"name":"Ultra-wide-band millimeter-wave generator using spin torque oscillator with strong interlayer exchange couplings.","description":"Recent increased development interest in millimeter-wave oscillator devices has necessitated realization of small oscillators with high frequency, wide frequency tunability, and room-temperature operation. Spin-torque oscillators (STOs) are fascinating candidates for such applications because of their nanometer size and suitability for room-temperature operation. However, their oscillation frequency and tunable range are limited to the order of 100 MHz-10 GHz. Here, we propose use of bilinear (J<sub>1</sub>) and biquadratic (J<sub>2</sub>) interlayer exchange couplings between ferromagnets in STOs to overcome these problems. The bilinear coupling contributes to oscillation frequency enhancement, whereas the biquadratic coupling facilitates frequency tunability via a current. Using micromagnetic simulation with parameters estimated from a material with small saturation magnetization, for J<sub>1</sub> = 0 and J<sub>2</sub> =  - 1.0 mJ/m<sup>2</sup>, respectively, we find that the STO exhibits high frequency from 23 to 576 GHz and that its tunability reaches 61 GHz/(10<sup>11</sup> A/m<sup>2</sup>) for current densities of - 0.5 to - 9.5 × 10<sup>11</sup> A/m<sup>2</sup>. An analytical theory based on the macrospin model is also developed, which exhibits good quantitative agreement with the micromagnetic simulations. These results introduce new possibilities for spintronics applications in high-frequency devices such as next-generation mobile communications.","dates":{"release":"2022-01-01T00:00:00Z","publication":"2022 Jul","modification":"2025-04-04T10:47:47.091Z","creation":"2025-04-04T10:47:47.091Z"},"accession":"S-EPMC9296563","cross_references":{"pubmed":["35854024"],"doi":["10.1038/s41598-022-15014-y"]}}