Fermi-Level-Dependent Charge-to-Spin Conversion of the Two-Dimensional Electron Gas at the γ - Al2 O3/KTaO3 Interface

Zhang，Hui1; Zhu，Zengtai2; Zhu，Yungu1; Chen，Xiaobing3,4,5; Jiang，Qisheng2; Wei，Jinwu6; Zhao，Chenbo7,8; Zhang，Jine1; Han，Furong1; Yang，Huaiwen1; Zhu，Dapeng1; Wu，Hao2; Chen，Yuansha3,4; Hu，Fengxia2,3,4; Shen，Baogen2,3,4; Zhao，Weisheng1; Zhang，Jing2; Yu，Guoqiang2,3,9; Sun，Jirong2,3,4,10

2023-03-01

10.1103/PhysRevApplied.19.034045

Physical Review Applied   Impact Factor & Quartile

2331-7019

2331-7019

Charge-to-spin conversion is crucial for the application of emerging spintronic devices. A two-dimensional electron gas (2DEG) at a complex oxide interface usually possesses strong Rashba spin-orbit coupling, and spin-momentum locking offers a great possibility for efficient charge-to-spin conversion through the Rashba-Edelstein effect. Here, we report the fabrication of metallic 2DEGs in γ-Al2O3/KTaO3 spinel/perovskite heterostructures and investigate the charge-to-spin conversion for Py/γ-Al2O3/KTaO3 devices using the technique of spin-torque ferromagnetic resonance. The sizable spin splitting of the band structure results in a large current-induced spin-orbit torque efficiency with values up to around 3.6 at 5 K and about 1.1 at 300 K, which are more than an order of magnitude higher than those of heavy metals (0.07 for Pt at 300 K). Moreover, both theoretical and experimental results show that the charge-to-spin conversion is strongly dependent on the position of the Fermi level. These results demonstrate that optimizing the band filling of a KTaO3-based 2DEG is crucial for maximizing the conversion efficiency.

SCI

English

Others

open research fund of Songshan Lake Materials Laboratory[2022SLABFN23] ; Science Center of the National Science Foundation of China[52088101] ; National Key Research and Development Program of China["2018YFA0305704","2019YFA0308401","2019YFA0704904","2022YFA1403302","2021YFA1400300","2021YFB 3501202","2020YFA0711502"] ; National Natural Science Foundation of China["12004022","11934016","51972335","12104027","12104029","XDB33030200"] ; Chinese Academy of Sciences["ZDRW-CN-2021-3","2022A1515110648"] ; Guangdong Basic and Applied Basic Research Foundation["2023A1515010953","2022B1515120058","11921004"] ; null[12274443]

Physics

Physics, Applied

WOS:000960874400005

AMER PHYSICAL SOC

2-s2.0-85151404061

Scopus

1.School of Integrated Circuit Science and Engineering,Beihang University,Beijing,100191,China
2.Songshan Lake Materials Laboratory,Dongguan,Guangdong,523808,China
3.Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing,100190,China
4.School of Physical Sciences,University of Chinese Academy of Sciences,Beijing,100049,China
5.Shenzhen Institute for Quantum Science and Engineering (SIQSE),Department of Physics,Southern University of Science and Technology,Shenzhen,518055,China
6.Key Laboratory for Magnetism and Magnetic Materials,The Ministry of Education,Lanzhou University,Lanzhou,730000,China
7.School of Science and Engineering,The Chinese University of HongKong,Shenzhen,Guangdong,518172,China
8.Department of Chemical Physics,University of Science and Technology of China,Hefei,Anhui,230026,China
9.Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing,100049,China
10.Spintronics Institute,Jinan University,Jinan,Shandong Provence,250022,China

Zhang，Hui,Zhu，Zengtai,Zhu，Yungu,et al. Fermi-Level-Dependent Charge-to-Spin Conversion of the Two-Dimensional Electron Gas at the γ - Al2 O3/KTaO3 Interface[J]. Physical Review Applied,2023,19(3).

Zhang，Hui.,Zhu，Zengtai.,Zhu，Yungu.,Chen，Xiaobing.,Jiang，Qisheng.,...&Sun，Jirong.(2023).Fermi-Level-Dependent Charge-to-Spin Conversion of the Two-Dimensional Electron Gas at the γ - Al2 O3/KTaO3 Interface.Physical Review Applied,19(3).

Zhang，Hui,et al."Fermi-Level-Dependent Charge-to-Spin Conversion of the Two-Dimensional Electron Gas at the γ - Al2 O3/KTaO3 Interface".Physical Review Applied 19.3(2023).