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Liang Y, Yi D, Nan T, Liu S, Zhao L, Zhang Y, Chen H, Xu T, Dai M, Hu JM, Xu B, Shi J, Jiang W, Yu R, Lin YH. Field-free spin-orbit switching of perpendicular magnetization enabled by dislocation-induced in-plane symmetry breaking. Nat Commun 2023; 14:5458. [PMID: 37673896 PMCID: PMC10482861 DOI: 10.1038/s41467-023-41163-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 08/25/2023] [Indexed: 09/08/2023] Open
Abstract
Current induced spin-orbit torque (SOT) holds great promise for next generation magnetic-memory technology. Field-free SOT switching of perpendicular magnetization requires the breaking of in-plane symmetry, which can be artificially introduced by external magnetic field, exchange coupling or device asymmetry. Recently it has been shown that the exploitation of inherent crystal symmetry offers a simple and potentially efficient route towards field-free switching. However, applying this approach to the benchmark SOT materials such as ferromagnets and heavy metals is challenging. Here, we present a strategy to break the in-plane symmetry of Pt/Co heterostructures by designing the orientation of Burgers vectors of dislocations. We show that the lattice of Pt/Co is tilted by about 1.2° when the Burgers vector has an out-of-plane component. Consequently, a tilted magnetic easy axis is induced and can be tuned from nearly in-plane to out-of-plane, enabling the field-free SOT switching of perpendicular magnetization components at room temperature with a relatively low current density (~1011 A/m2) and excellent stability (> 104 cycles). This strategy is expected to be applicable to engineer a wide range of symmetry-related functionalities for future electronic and magnetic devices.
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Affiliation(s)
- Yuhan Liang
- School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Di Yi
- School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Tianxiang Nan
- School of Integrated Circuits and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing, China
| | - Shengsheng Liu
- School of Materials Science and Engineering, Tsinghua University, Beijing, China
- National Center for Electron Microscopy in Beijing, Tsinghua University, Beijing, China
| | - Le Zhao
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing, China
| | - Yujun Zhang
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Hetian Chen
- School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Teng Xu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing, China
| | - Minyi Dai
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Jia-Mian Hu
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Ben Xu
- Graduate School, China Academy of Engineering Physics, Beijing, China
| | - Ji Shi
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Wanjun Jiang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China.
- Frontier Science Center for Quantum Information, Tsinghua University, Beijing, China.
| | - Rong Yu
- School of Materials Science and Engineering, Tsinghua University, Beijing, China.
- National Center for Electron Microscopy in Beijing, Tsinghua University, Beijing, China.
| | - Yuan-Hua Lin
- School of Materials Science and Engineering, Tsinghua University, Beijing, China.
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Kateel V, Krizakova V, Rao S, Cai K, Gupta M, Monteiro MG, Yasin F, Sorée B, De Boeck J, Couet S, Gambardella P, Kar GS, Garello K. Field-Free Spin-Orbit Torque Driven Switching of Perpendicular Magnetic Tunnel Junction through Bending Current. NANO LETTERS 2023. [PMID: 37295781 DOI: 10.1021/acs.nanolett.3c00639] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Current-induced spin-orbit torques (SOTs) enable fast and efficient manipulation of the magnetic state of magnetic tunnel junctions (MTJs), making them attractive for memory, in-memory computing, and logic applications. However, the requirement of the external magnetic field to achieve deterministic switching in perpendicularly magnetized SOT-MTJs limits its implementation for practical applications. Here, we introduce a field-free switching (FFS) solution for the SOT-MTJ device by shaping the SOT channel to create a "bend" in the SOT current. The resulting bend in the charge current creates a spatially nonuniform spin current, which translates into inhomogeneous SOT on an adjacent magnetic free layer enabling deterministic switching. We demonstrate FFS experimentally on scaled SOT-MTJs at nanosecond time scales. This proposed scheme is scalable, material-agnostic, and readily compatible with wafer-scale manufacturing, thus creating a pathway for developing purely current-driven SOT systems.
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Affiliation(s)
- Vaishnavi Kateel
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | - Viola Krizakova
- Department of Materials, ETH Zurich, 8093 Zürich, Switzerland
| | | | | | | | - Maxwel Gama Monteiro
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | | | - Bart Sorée
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | - Johan De Boeck
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Department of Electrical Engineering ESAT, KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | | | | | | | - Kevin Garello
- IMEC Kapeldreef 75, B-3001 Leuven, Belgium
- Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, SPINTEC, 38000 Grenoble, France
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