Volume 1 Issue 2
June  2022
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Hao Wu, Jing Zhang, Baoshan Cui, Seyed Armin Razavi, Xiaoyu Che, Quanjun Pan, Di Wu, Guoqiang Yu, Xiufeng Han, Kang L Wang. Field-free approaches for deterministic spin–orbit torque switching of the perpendicular magnet[J]. Materials Futures, 2022, 1(2): 022201. doi: 10.1088/2752-5724/ac6577
Citation: Hao Wu, Jing Zhang, Baoshan Cui, Seyed Armin Razavi, Xiaoyu Che, Quanjun Pan, Di Wu, Guoqiang Yu, Xiufeng Han, Kang L Wang. Field-free approaches for deterministic spin–orbit torque switching of the perpendicular magnet[J]. Materials Futures, 2022, 1(2): 022201. doi: 10.1088/2752-5724/ac6577
Topical Review •

Field-free approaches for deterministic spin–orbit torque switching of the perpendicular magnet

© 2022 The Author(s). Published by IOP Publishing Ltd on behalf of the Songshan Lake Materials Laboratory
Materials Futures, Volume 1, Number 2
  • Received Date: 2022-02-02
  • Accepted Date: 2022-04-06
  • Publish Date: 2022-04-22
  • All-electrical driven magnetization switching attracts much attention in next-generation spintronic memory and logic devices, particularly in magnetic random-access memory (MRAM) based on the spin–orbit torque (SOT), i.e. SOT-MRAM, due to its advantages of low power consumption, fast write/read speed, and improved endurance, etc. For conventional SOT-driven switching of the magnet with perpendicular magnetic anisotropy, an external assisted magnetic field is necessary to break the inversion symmetry of the magnet, which not only induces the additional power consumption but also makes the circuit more complicated. Over the last decade, significant effort has been devoted to field-free magnetization manipulation by using SOT. In this review, we introduce the basic concepts of SOT. After that, we mainly focus on several approaches to realize the field-free deterministic SOT switching of the perpendicular magnet. The mechanisms mainly include mirror symmetry breaking, chiral symmetry breaking, exchange bias, and interlayer exchange coupling. Furthermore, we show the recent progress in the study of SOT with unconventional origin and symmetry. The final section is devoted to the industrial-level approach for potential applications of field-free SOT switching in SOT-MRAM technology.

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  • [1]
    Wolf S A, Awschalom D D, Buhrman R A, Daughton J M, von Molnar S, Roukes M L, Chtchelkanova A Y and Treger D M 2001 Spintronics: a spin-based electronics vision for the future Science 294 1488–95
    Baibich M N, Broto J M, Fert A, Van Dau F N, Petroff F, Etienne P, Creuzet G, Friederich A and Chazelas J 1988 Giant magnetoresistance of (001)Fe/(001)Cr magnetic superlattices Phys. Rev. Lett. 61 2472–5
    Binasch G, Grunberg P, Saurenbach F and Zinn W 1989 Enhanced magnetoresistance in layered magnetic structures with antiferromagnetic interlayer exchange Phys. Rev. B 39 4828–30
    Parkin S, Xin J, Kaiser C, Panchula A, Roche K and Samant M 2003 Magnetically engineered spintronic sensors and memory Proc. IEEE 91 661–80
    Julliere M 1975 Tunneling between ferromagnetic films Phys. Lett. A 54 225–6
    Miyazaki T and Tezuka N 1995 Giant magnetic tunneling effect in Fe/Al2O3/Fe junction J. Magn. Magn. Mater. 139 L231–4
    Moodera J S, Kinder L R, Wong T M and Meservey R 1995 Large magnetoresistance at room temperature in ferromagnetic thin film tunnel junctions Phys. Rev. Lett. 74 3273–6
    Parkin S S P, Kaiser C, Panchula A, Rice P M, Hughes B, Samant M and Yang S-H 2004 Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriers Nat. Mater. 3 862
    Yuasa S, Nagahama T, Fukushima A, Suzuki Y and Ando K 2004 Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctions Nat. Mater. 3 868
    Butler W H, Zhang X G, Schulthess T C and MacLaren J M 2001 Spin-dependent tunneling conductance of Fe|MgO|Fe sandwiches Phys. Rev. B 63 054416
    Berger L 1996 Emission of spin waves by a magnetic multilayer traversed by a current Phys. Rev. B 54 9353–8
    Slonczewski J C 1996 Current-driven excitation of magnetic multilayers J. Magn. Magn. Mater. 159 L1–L7
    Martinez E, Emori S, Perez N, Torres L and Beach G S D 2014 Current-driven dynamics of Dzyaloshinskii domain walls in the presence of in-plane fields: full micromagnetic and one-dimensional analysis J. Appl. Phys. 115 213909
    Zeinali B, Madsen J K, Raghavan P and Moradi F 2017 Ultra-fast SOT-MRAM cell with STT current for deterministic switching 2017 IEEE Int. Conf. on Computer Design (ICCD) pp 463–8
    Perel M I D V I 1971 Possibility of orienting electron spins with current JETP Lett. 13 467–9 (www.jetpletters.ru/ps/1587/article_24366.shtml)
    Dyakonov V I P M I 1971 Current-induced spin orientation of electrons in semiconductors Phys. Lett. A 35 459
    Hirsch J E 1999 Spin Hall effect Phys. Rev. Lett. 83 1834–7
    Zhang S F 2000 Spin Hall effect in the presence of spin diffusion Phys. Rev. Lett. 85 393–6
    Edelstein V M 1990 Spin polarization of conduction electrons induced by electric current in two-dimensional asymmetric electron systems Solid State Commun. 73 233–5
    Dresselhaus G 1955 Spin-orbit coupling effects in zinc blende structures Phys. Rev. 100 580–6
    Rashba R E and Bychkov Y A 1984 Properties of a 2D electron-gas with lifted spectral degeneracy JETP Lett. 39 78–81
    Kim K-W, Seo S-M, Ryu J, Lee K-J and Lee H-W 2012 Magnetization dynamics induced by in-plane currents in ultrathin magnetic nanostructures with Rashba spin-orbit coupling Phys. Rev. B 85 180404
    Wang X and Manchon A 2012 Diffusive spin dynamics in ferromagnetic thin films with a Rashba interaction Phys. Rev. Lett. 108 117201
    Haney P M, Lee H-W, Lee K-J, Manchon A and Stiles M D 2013 Current induced torques and interfacial spin-orbit coupling: semiclassical modeling Phys. Rev. B 87 174411
    Miron I M, Garello K, Gaudin G, Zermatten P J, Costache M V, Auffret S, Bandiera S, Rodmacq B, Schuhl A and Gambardella P 2011 Perpendicular switching of a single ferromagnetic layer induced by in-plane current injection Nature 476 189
    Liu L, Pai C F, Li Y, Tseng H W, Ralph D C and Buhrman R A 2012 Spin-torque switching with the giant spin Hall effect of tantalum Science 336 555–8
    Liu L, Pai C F, Ralph D C and Buhrman R A 2012 Magnetic oscillations driven by the spin Hall effect in 3-terminal magnetic tunnel junction devices Phys. Rev. Lett. 109 186602
    Lee K-S, Lee S-W, Min B-C and Lee K-J 2013 Threshold current for switching of a perpendicular magnetic layer induced by spin Hall effect Appl. Phys. Lett. 102 112410
    Yan S and Bazaliy Y B 2015 Phase diagram and optimal switching induced by spin Hall effect in a perpendicular magnetic layer Phys. Rev. B 91 214424
    Peng S, Zhu D, Zhou J, Zhang B, Cao A, Wang M, Cai W, Cao K and Zhao W 2019 Modulation of heavy metal/ferromagnetic metal interface for high-performance spintronic devices Adv. Electron. Mater. 5 1900134
    Yu G et al 2014 Switching of perpendicular magnetization by spin–orbit torques in the absence of external magnetic fields Nat. Nanotechnol. 9 548–54
    Yu G, Chang L-T, Akyol M, Upadhyaya P, He C, Li X, Wong K L, Amiri P K and Wang K L 2014 Current-driven perpendicular magnetization switching in Ta/CoFeB/[TaOx or MgO/TaOx] films with lateral structural asymmetry Appl. Phys. Lett. 105 102411
    Chen T-Y, Chan H-I, Liao W-B and Pai C-F 2018 Current-induced spin-orbit torque and field-free switching in Mo-based magnetic heterostructures Phys. Rev. Appl. 10 044038
    Razavi A, Wu H, Shao Q, Fang C, Dai B, Wong K, Han X, Yu G and Wang K L 2020 Deterministic spin–orbit torque switching by a light-metal insertion Nano Lett. 20 3703–9
    Akyol M, Yu G, Alzate J G, Upadhyaya P, Li X, Wong K L, Ekicibil A, Amiri P K and Wang K L 2015 Current-induced spin-orbit torque switching of perpendicularly magnetized Hf|CoFeB|MgO and Hf|CoFeB|TaOx structures Appl. Phys. Lett. 106 162409
    Pai C-F, Mann M, Tan A J and Beach G S D 2016 Determination of spin torque efficiencies in heterostructures with perpendicular magnetic anisotropy Phys. Rev. B 93 144409
    Razavi A, Wu H, Dai B, He H, Wu D, Wong K, Yu G and Wang K 2020 Spin–orbit torques in structures with asymmetric dusting layers Appl. Phys. Lett. 117 182403
    Cui B et al 2019 Field-free spin–orbit torque switching of perpendicular magnetization by the Rashba interface ACS Appl. Mater. Interfaces 11 39369–75
    Yu G et al 2016 Competing effect of spin-orbit torque terms on perpendicular magnetization switching in structures with multiple inversion asymmetries Sci. Rep. 6 23956
    Torrejon J, Garcia-Sanchez F, Taniguchi T, Sinha J, Mitani S, Kim J-V and Hayashi M 2015 Current-driven asymmetric magnetization switching in perpendicularly magnetized CoFeB/MgO heterostructures Phys. Rev. B 91 214434
    Chuang T C, Pai C F and Huang S Y 2019 Cr-induced perpendicular magnetic anisotropy and field-free spin-orbit-torque switching Phys. Rev. Appl. 11 061005
    You L, Lee O, Bhowmik D, Labanowski D, Hong J, Bokor J and Salahuddin S 2015 Switching of perpendicularly polarized nanomagnets with spin orbit torque without an external magnetic field by engineering a tilted anisotropy Proc. Natl Acad. Sci. 112 10310
    Dzyaloshinsky I 1958 A thermodynamic theory of ‘weak’ ferromagnetism of antiferromagnetics J. Phys. Chem. Solids 4 241–55
    Moriya T 1960 Anisotropic superexchange interaction and weak ferromagnetism Phys. Rev. 120 91–98
    Je S-G, Kim D-H, Yoo S-C, Min B-C, Lee K-J and Choe S-B 2013 Asymmetric magnetic domain-wall motion by the Dzyaloshinskii-Moriya interaction Phys. Rev. B 88 214401
    Chen B, Lourembam J, Goolaup S and Lim S T 2019 Field-free spin-orbit torque switching of a perpendicular ferromagnet with Dzyaloshinskii-Moriya interaction Appl. Phys. Lett. 114 022401
    Fert A, Reyren N and Cros V 2017 Magnetic skyrmions: advances in physics and potential applications Nat. Rev. Mater. 2 17031
    Chen G et al 2013 Novel chiral magnetic domain wall structure in Fe/Ni/Cu(001) films Phys. Rev. Lett. 110 177204
    Wu H et al 2021 Chiral symmetry breaking for deterministic switching of perpendicular magnetization by spin–orbit torque Nano Lett. 21 515–21
    MacNeill D, Stiehl G M, Guimaraes M H D, Buhrman R A, Park J and Ralph D C 2016 Control of spin–orbit torques through crystal symmetry in WTe2/ferromagnet bilayers Nat. Phys. 13 300–5
    Han D-S et al 2019 Long-range chiral exchange interaction in synthetic antiferromagnets Nat. Mater. 18 703–8
    Fern´andez-Pacheco A, Vedmedenko E, Ummelen F, Mansell R, Petit D and Cowburn R P 2019 Symmetry-breaking interlayer Dzyaloshinskii–Moriya interactions in synthetic antiferromagnets Nat. Mater. 18 679–84
    Legrand W, Chauleau J-Y, Maccariello D, Reyren N, Collin S, Bouzehouane K, Jaouen N, Cros V and Fert A 2018 Hybrid chiral domain walls and skyrmions in magnetic multilayers Sci. Adv. 4 eaat0415
    Li W et al 2019 Anatomy of Skyrmionic textures in magnetic multilayers Adv. Mater. 31 1807683
    Zheng Z et al 2021 Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with a vertical composition gradient Nat. Commun. 12 4555
    Zhang K et al 2022 Efficient and controllable magnetization switching induced by intermixing-enhanced bulk spin–orbit torque in ferromagnetic multilayers Appl. Phys. Rev. 9 011407
    Fukami S, Zhang C, DuttaGupta S, Kurenkov A and Ohno H 2016 Magnetization switching by spin-orbit torque in an antiferromagnet-ferromagnet bilayer system Nat. Mater. 15 535–41
    Oh Y W et al 2016 Field-free switching of perpendicular magnetization through spin-orbit torque in antiferromagnet/ferromagnet/oxide structures Nat. Nanotechnol. 11 878–84
    Li W, Peng S, Lu J, Wu H, Li X, Xiong D, Zhang Y, Zhang Y, Wang K L and Zhao W 2021 Experimental demonstration of voltage-gated spin-orbit torque switching in an antiferromagnet/ferromagnet structure Phys. Rev. B 103 094436
    Peng S et al 2020 Exchange bias switching in an antiferromagnet/ferromagnet bilayer driven by spin–orbit torque Nat. Electron. 3 757–64
    Peng S Z, Lu J Q, Li W X, Wang L Z, Zhang H, Li X, Wang K L and Zhao W S 2019 Field-free switching of perpendicular magnetization through voltage-gated spin-orbit torque IEEE Int. Electron Devices Meeting pp 28.26.21–24
    van den Brink A, Vermijs G, Solignac A, Koo J, Kohlhepp J T, Swagten H J M and Koopmans B 2016 Field-free magnetization reversal by spin-Hall effect and exchange bias Nat. Commun. 7 10854
    Razavi S A et al 2017 Joule heating effect on field-free magnetization switching by spin-orbit torque in exchange-biased systems Phys. Rev. Appl. 7 024023
    Lau Y C, Betto D, Rode K, Coey J M and Stamenov P 2016 Spin-orbit torque switching without an external field using interlayer exchange coupling Nat. Nanotechnol. 11 758–62
    Murray N, Liao W-B, Wang T-C, Chang L-J, Tsai L-Z, Tsai T-Y, Lee S-F and Pai C-F 2019 Field-free spin-orbit torque switching through domain wall motion Phys. Rev. B 100 104441
    Garello K, Miron I M, Avci C O, Freimuth F, Mokrousov Y, Blügel S, Auffret S, Boulle O, Gaudin G and Gambardella P 2013 Symmetry and magnitude of spin–orbit torques in ferromagnetic heterostructures Nat. Nanotechnol. 8 587–93
    Wang Z, Zhang L, Wang M, Wang Z, Zhu D, Zhang Y and Zhao W 2018 High-density NAND-like spin transfer torque memory with spin orbit torque erase operation IEEE Electron Device Lett. 39 343–6
    Cai W et al 2021 Sub-ns field-free switching in perpendicular magnetic tunnel junctions by the interplay of spin transfer and orbit torques IEEE Electron Device Lett. 42 704–7
    Kimata M et al 2019 Magnetic and magnetic inverse spin Hall effects in a non-collinear antiferromagnet Nature 565 627–30
    Wang W et al 2019 Anomalous spin–orbit torques in magnetic single-layer films Nat. Nanotechnol. 14 819–24
    Bose A, Lam D D, Bhuktare S, Dutta S, Singh H, Jibiki Y, Goto M, Miwa S and Tulapurkar A A 2018 Observation of anomalous spin torque generated by a ferromagnet Phys. Rev. Appl. 9 064026
    Gibbons J D, MacNeill D, Buhrman R A and Ralph D C 2018 Reorientable spin direction for spin current produced by the anomalous Hall effect Phys. Rev. Appl. 9 064033
    Hönemann A, Herschbach C, Fedorov D V, Gradhand M and Mertig I 2019 Spin and charge currents induced by the spin Hall and anomalous Hall effects upon crossing ferromagnetic/nonmagnetic interfaces Phys. Rev. B 99 024420
    Luo Z, Zhang Q, Xu Y, Yang Y, Zhang X and Wu Y 2019 Spin-orbit torque in a single ferromagnetic layer induced by surface spin rotation Phys. Rev. Appl. 11 064021
    Yu J et al 2019 Long spin coherence length and bulk-like spin–orbit torque in ferrimagnetic multilayers Nat. Mater. 18 29–34
    Zhou J et al 2019 Large spin-orbit torque efficiency enhanced by magnetic structure of collinear antiferromagnet IrMn Sci. Adv. 5 eaau6696
    Okuno T et al 2019 Spin-transfer torques for domain wall motion in antiferromagnetically coupled ferrimagnets Nat. Electron. 2 389–93
    You Y et al 2021 Cluster magnetic octupole induced out-of-plane spin polarization in antiperovskite antiferromagnet Nat. Commun. 12 6524
    Kondou K, Chen H, Tomita T, Ikhlas M, Higo T, MacDonald A H, Nakatsuji S and Otani Y 2021 Giant field-like torque by the out-of-plane magnetic spin Hall effect in a topological antiferromagnet Nat. Commun. 12 6491
    Amin V P, Li J, Stiles M D and Haney P M 2019 Intrinsic spin currents in ferromagnets Phys. Rev. B 99 220405
    Sun C, Deng J, Rafi-Ul-Islam S M, Liang G, Yang H and Jalil M B A 2019 Field-free switching of perpendicular magnetization through spin hall and anomalous hall effects in ferromagnet–heavy-metal–ferromagnet structures Phys. Rev. Appl. 12 034022
    Seki T, Iihama S, Taniguchi T and Takanashi K 2019 Large spin anomalous Hall effect in L10–FePt: symmetry and magnetization switching Phys. Rev. B 100 144427
    Li J-Y, Wang R-Q, Deng M-X and Yang M 2019 In-plane magnetization effect on current-induced spin-orbit torque in a ferromagnet/topological insulator bilayer with hexagonal warping Phys. Rev. B 99 155139
    Sokolewicz R J, Ado I A, Katsnelson M I, Ostrovsky P M and Titov M 2019 Spin-torque resonance due to diffusive dynamics at the surface of a topological insulator Phys. Rev. B 99 214444
    Ghosh S and Manchon A 2019 Nonequilibrium spin density and spin-orbit torque in a three-dimensional topological insulator/antiferromagnet heterostructure Phys. Rev. B 100 014412
    Gweon H K, Lee K-J and Lim S H 2019 Influence of MgO sputtering power and post annealing on strength and angular dependence of spin-orbit torques in Pt/Co/MgO trilayers Phys. Rev. Appl. 11 014034
    Baek S H C, Amin V P, Oh Y W, Go G, Lee S J, Lee G H, Kim K-J, Stiles M D, Park B-G and Lee K-J 2018 Spin currents and spin–orbit torques in ferromagnetic trilayers Nat. Mater. 17 509–13
    Kurebayashi D and Nagaosa N 2019 Theory of current-driven dynamics of spin textures on the surface of a topological insulator Phys. Rev. B 100 134407
    Safranski C, Montoya E A and Krivorotov I N 2019 Spin–orbit torque driven by a planar Hall current Nat. Nanotechnol. 14 27–30
    Humphries A M, Wang T, Edwards E R J, Allen S R, Shaw J M, Nembach H T, Xiao J Q, Silva T J and Fan X 2017 Observation of spin-orbit effects with spin rotation symmetry Nat. Commun. 8 911
    Liu L et al 2021 Symmetry-dependent field-free switching of perpendicular magnetization Nat. Nanotechnol. 16 277–82
    Liu L et al 2019 Current-induced magnetization switching in all-oxide heterostructures Nat. Nanotechnol. 14 939–44
    Kong W J, Wan C H, Wang X, Tao B S, Huang L, Fang C, Guo C Y, Guang Y, Irfan M and Han X F 2019 Spin–orbit torque switching in a T-type magnetic configuration with current orthogonal to easy axes Nat. Commun. 10 233
    Mishra R, Mahfouzi F, Kumar D, Cai K, Chen M, Qiu X, Kioussis N and Yang H 2019 Electric-field control of spin accumulation direction for spin-orbit torques Nat. Commun. 10 248
    Wang X K K L, Upadhyaya P, Fan Y, Shao Q, Yu G and Amiri P K 2016 Electric-field control of spin-orbit interaction for low-power spintronics Proc. IEEE 104 1974–2008
    Garello F Y K et al 2019 Manufacturable 300 mm platform solution for field-free switching SOT-MRAM Symp. on VLSI Circuits pp T194–5
    Wu O G H et al 2018 Parasitic resistance reduction strategies for advanced CMOS FinFETs beyond 7 nm IEEE Int. Electron Devices Meeting (IEDM) pp 35.34.31–34
    Wang Z, Li Z, Wang M, Wu B, Zhu D and Zhao W 2019 Field-free spin-orbit-torque switching of perpendicular magnetization aided by uniaxial shape anisotropy Nanotechnology 30 375202
    Wang Z, Wu B, Li Z, Lin X, Yang J, Zhang Y and Zhao W 2018 Evaluation of ultrahigh-speed magnetic memories using field-free spin–orbit torque IEEE Trans. Magn. 54 1–5
    Luo Y T Z, Dong Y, Lu C and Liu C W 2018 Field-free spin-orbit torque switching of perpendicular magnetic tunnel junction utilizing voltage-controlled magnetic anisotropy pulse width optimization Non-Volatile Memory Technology Symp. (NVMTS) pp 1–5
    Honjo H et al 2019 First demonstration of field-free SOT-MRAM with 0.35 ns write speed and 70 thermal stability under 400 ◦C thermal tolerance by canted SOT structure and its advanced patterning/SOT channel technology IEEE Int. Electron Devices Meeting (IEDM) pp 28.25.21–24
    Wang M et al 2018 Field-free switching of a perpendicular magnetic tunnel junction through the interplay of spin–orbit and spin-transfer torques Nat. Electron. 1 582–8
    Fukami S, Anekawa T, Zhang C and Ohno H 2016 A spin-orbit torque switching scheme with collinear magnetic easy axis and current configuration Nat. Nanotechnol. 11 621–5
    Alexander Makaro V S and Selberherr S 2018 Field-free fast reliable deterministic switching in perpendicular spin-orbit torque MRAM cells Int. Conf. on Simulation of Semiconductor Processes and Devices (SISPAD)
    Cai K et al 2017 Electric field control of deterministic current-induced magnetization switching in a hybrid ferromagnetic/ferroelectric structure Nat. Mater. 16 712–6
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