Giant Spin‐Orbit Torque in Sputter‐Deposited Bi Films
Abstract Bismuth (Bi) has the strongest spin‐orbit coupling among non‐radioactive elements and is thus a promising material for efficient charge‐to‐spin conversion. However, previous electrical detections have reported controversial results for the conversion efficiency. In this study, an optical de...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-11-01
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| Series: | Advanced Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/advs.202303831 |
| _version_ | 1827771032701763584 |
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| author | Sumin Kim Hyun‐Woo Lee Gyung‐Min Choi |
| author_facet | Sumin Kim Hyun‐Woo Lee Gyung‐Min Choi |
| author_sort | Sumin Kim |
| collection | DOAJ |
| description | Abstract Bismuth (Bi) has the strongest spin‐orbit coupling among non‐radioactive elements and is thus a promising material for efficient charge‐to‐spin conversion. However, previous electrical detections have reported controversial results for the conversion efficiency. In this study, an optical detection of a spin‐orbit torque is reported in a Bi/CoFeB bilayer with a polycrystalline texture of (012) and (003). Taking advantage of the optical detection, spin‐orbit torque is accurately separated from the Oersted field and achieves a giant damping‐like torque efficiency of +0.5, verifying efficient charge‐to‐spin conversion. This study also demonstrates a field‐like torque efficiency of −0.1. For the mechanism of the charge‐to‐spin conversion, the bulk spin Hall effect and the interface Rashba‐Edelstein effect are considered. |
| first_indexed | 2024-03-11T12:47:57Z |
| format | Article |
| id | doaj.art-a70547ffbb994bbe9d4db6a4bc1d2c44 |
| institution | Directory Open Access Journal |
| issn | 2198-3844 |
| language | English |
| last_indexed | 2024-03-11T12:47:57Z |
| publishDate | 2023-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advanced Science |
| spelling | doaj.art-a70547ffbb994bbe9d4db6a4bc1d2c442023-11-04T08:56:52ZengWileyAdvanced Science2198-38442023-11-011031n/an/a10.1002/advs.202303831Giant Spin‐Orbit Torque in Sputter‐Deposited Bi FilmsSumin Kim0Hyun‐Woo Lee1Gyung‐Min Choi2Department of Energy Science Sungkyunkwan University Suwon 16419 South KoreaDepartment of Physics Pohang University of Science and Technology Pohang 37673 South KoreaDepartment of Energy Science Sungkyunkwan University Suwon 16419 South KoreaAbstract Bismuth (Bi) has the strongest spin‐orbit coupling among non‐radioactive elements and is thus a promising material for efficient charge‐to‐spin conversion. However, previous electrical detections have reported controversial results for the conversion efficiency. In this study, an optical detection of a spin‐orbit torque is reported in a Bi/CoFeB bilayer with a polycrystalline texture of (012) and (003). Taking advantage of the optical detection, spin‐orbit torque is accurately separated from the Oersted field and achieves a giant damping‐like torque efficiency of +0.5, verifying efficient charge‐to‐spin conversion. This study also demonstrates a field‐like torque efficiency of −0.1. For the mechanism of the charge‐to‐spin conversion, the bulk spin Hall effect and the interface Rashba‐Edelstein effect are considered.https://doi.org/10.1002/advs.202303831bismuthRashba‐Edelstein effectspin Hall effectspin‐orbit torque |
| spellingShingle | Sumin Kim Hyun‐Woo Lee Gyung‐Min Choi Giant Spin‐Orbit Torque in Sputter‐Deposited Bi Films Advanced Science bismuth Rashba‐Edelstein effect spin Hall effect spin‐orbit torque |
| title | Giant Spin‐Orbit Torque in Sputter‐Deposited Bi Films |
| title_full | Giant Spin‐Orbit Torque in Sputter‐Deposited Bi Films |
| title_fullStr | Giant Spin‐Orbit Torque in Sputter‐Deposited Bi Films |
| title_full_unstemmed | Giant Spin‐Orbit Torque in Sputter‐Deposited Bi Films |
| title_short | Giant Spin‐Orbit Torque in Sputter‐Deposited Bi Films |
| title_sort | giant spin orbit torque in sputter deposited bi films |
| topic | bismuth Rashba‐Edelstein effect spin Hall effect spin‐orbit torque |
| url | https://doi.org/10.1002/advs.202303831 |
| work_keys_str_mv | AT suminkim giantspinorbittorqueinsputterdepositedbifilms AT hyunwoolee giantspinorbittorqueinsputterdepositedbifilms AT gyungminchoi giantspinorbittorqueinsputterdepositedbifilms |