Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions
With the growing demand for high‐speed electronic devices with low energy consumption, spin–orbit torque (SOT) has become a significant focus. SOT can switch the magnetization direction in a material system with broken inversion symmetry, such as a normal metal (NM)/ferromagnet (FM) heterojunction....
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| Format: | Article |
| Language: | English |
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Wiley-VCH
2024-02-01
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| Series: | Small Science |
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| Online Access: | https://doi.org/10.1002/smsc.202300224 |
| _version_ | 1797306834519851008 |
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| author | Min Hyeok Lee Seok-Jong Kim Seok In Yoon Jeong Kyu Lee Han Seok Ko Gyusang Kim Seokhie Hong Kyung-Jin Lee Young Keun Kim |
| author_facet | Min Hyeok Lee Seok-Jong Kim Seok In Yoon Jeong Kyu Lee Han Seok Ko Gyusang Kim Seokhie Hong Kyung-Jin Lee Young Keun Kim |
| author_sort | Min Hyeok Lee |
| collection | DOAJ |
| description | With the growing demand for high‐speed electronic devices with low energy consumption, spin–orbit torque (SOT) has become a significant focus. SOT can switch the magnetization direction in a material system with broken inversion symmetry, such as a normal metal (NM)/ferromagnet (FM) heterojunction. The SOT consists of two mutually orthogonal vector components along with the injected current direction: the transverse damping‐like torque (DLT) and the longitudinal field‐like torque (FLT). Numerous studies have mainly centered on the DLT for the SOT switching mechanism. However, DLT and FLT are essential to enhance SOT efficiency because FLT boosts the magnetization precession motion. Herein, heterojunctions consisting of NM 1 (Ta, W, or Pt)/NM 2 (Nb)/FM (CoFeB) are devised to manipulate the FLT‐to‐DLT ratio (η) through the change in Nb thickness. Furthermore, experimental confirmation exists for reducing threshold current as η increases. The SOT devices with substantial η generate random numbers. The National Institute of Standards and Technology Special Publication 800‐90B test verifies randomness and confirms that the SOT devices are beneficial sources for true random number generators (TRNGs). These findings indicate the crucial role of FLT in the SOT switching process and underscore its significance in developing SOT‐based TRNG devices. |
| first_indexed | 2024-03-08T00:47:33Z |
| format | Article |
| id | doaj.art-eb3bce498219426cb9308bdeb86dd77d |
| institution | Directory Open Access Journal |
| issn | 2688-4046 |
| language | English |
| last_indexed | 2024-03-08T00:47:33Z |
| publishDate | 2024-02-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | Small Science |
| spelling | doaj.art-eb3bce498219426cb9308bdeb86dd77d2024-02-15T05:52:51ZengWiley-VCHSmall Science2688-40462024-02-0142n/an/a10.1002/smsc.202300224Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet HeterojunctionsMin Hyeok Lee0Seok-Jong Kim1Seok In Yoon2Jeong Kyu Lee3Han Seok Ko4Gyusang Kim5Seokhie Hong6Kyung-Jin Lee7Young Keun Kim8Department of Materials Science and Engineering Korea University Seoul 02841 Republic of KoreaDepartment of Physics Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of KoreaDepartment of Materials Science and Engineering Korea University Seoul 02841 Republic of KoreaDepartment of Materials Science and Engineering Korea University Seoul 02841 Republic of KoreaDepartment of Materials Science and Engineering Korea University Seoul 02841 Republic of KoreaInstitute of Cyber Security & Privacy (ICSP) School of Cybersecurity Korea University Seoul 02841 Republic of KoreaInstitute of Cyber Security & Privacy (ICSP) School of Cybersecurity Korea University Seoul 02841 Republic of KoreaDepartment of Physics Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of KoreaDepartment of Materials Science and Engineering Korea University Seoul 02841 Republic of KoreaWith the growing demand for high‐speed electronic devices with low energy consumption, spin–orbit torque (SOT) has become a significant focus. SOT can switch the magnetization direction in a material system with broken inversion symmetry, such as a normal metal (NM)/ferromagnet (FM) heterojunction. The SOT consists of two mutually orthogonal vector components along with the injected current direction: the transverse damping‐like torque (DLT) and the longitudinal field‐like torque (FLT). Numerous studies have mainly centered on the DLT for the SOT switching mechanism. However, DLT and FLT are essential to enhance SOT efficiency because FLT boosts the magnetization precession motion. Herein, heterojunctions consisting of NM 1 (Ta, W, or Pt)/NM 2 (Nb)/FM (CoFeB) are devised to manipulate the FLT‐to‐DLT ratio (η) through the change in Nb thickness. Furthermore, experimental confirmation exists for reducing threshold current as η increases. The SOT devices with substantial η generate random numbers. The National Institute of Standards and Technology Special Publication 800‐90B test verifies randomness and confirms that the SOT devices are beneficial sources for true random number generators (TRNGs). These findings indicate the crucial role of FLT in the SOT switching process and underscore its significance in developing SOT‐based TRNG devices.https://doi.org/10.1002/smsc.202300224damping-like torquefield-like torqueheterojunctionsspin–orbit torquetrue random number generators |
| spellingShingle | Min Hyeok Lee Seok-Jong Kim Seok In Yoon Jeong Kyu Lee Han Seok Ko Gyusang Kim Seokhie Hong Kyung-Jin Lee Young Keun Kim Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions Small Science damping-like torque field-like torque heterojunctions spin–orbit torque true random number generators |
| title | Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions |
| title_full | Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions |
| title_fullStr | Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions |
| title_full_unstemmed | Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions |
| title_short | Reduction of Operating Current by Harnessing the Field‐ and Damping‐Like Torque Ratios in Nonmagnet–Ferromagnet Heterojunctions |
| title_sort | reduction of operating current by harnessing the field and damping like torque ratios in nonmagnet ferromagnet heterojunctions |
| topic | damping-like torque field-like torque heterojunctions spin–orbit torque true random number generators |
| url | https://doi.org/10.1002/smsc.202300224 |
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