Enhanced Spin-Orbit Torque and Multilevel Current-Induced Switching in 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mrow><mml:mrow><mml:mi mathvariant="normal">W</mml:mi></mml:mrow></mml:mrow><mml:mo>/</mml:mo><mml:mi>Co</mml:mi><mml:mtext>−</mml:mtext><mml:mi>Tb</mml:mi><mml:mo>/</mml:mo><mml:mi>Pt</mml:mi></mml:math>
 Heterostructure

Interfacially asymmetric magnetic multilayers made of heavy metal/ferromagnet have attracted considerable attention in the spintronics community for accommodating spin-orbit torques and meanwhile for hosting chiral spin textures. In these multilayers, 1 the accompanied interfacial Dzyaloshinskii-Moriya interaction (iDMI) permits the formation of Néel-type spin textures. While significant progresses have been made in Co, CoFeB, Co 2 FeAl, CoFeGd based multilayers, it would be intriguing to identify new magnetic multilayers which could enable spin-torque controllability and meanwhile host nanoscale skyrmions. In this report, we first synthesize thin films made of permanent magnet SmCo 5 with perpendicular magnetic anisotropy, in which the deterministic spin-orbit torque (SOT) switching, enabled by the spin Hall effect, in Pt/SmCo 5 /Ta trilayer is demonstrated. Further, we show the stabilization of roomtemperature skyrmions with diameters approximately 100 nm in [Pt/SmCo 5 /Ta] 15 , together with a skyrmionium-like spin texture in [Pt/SmCo 5 /Ir] 15 multilayers. Based on the material specific parameters, micromagnetic simulations are also carried out.Results of which confirm the presence of chiral spin textures in this new material family. Through interfacial engineering, our results thus demonstrate that rare earth permanent magnet could be a new platform for studying the interfacial chiral spintronics.

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“…and Ir (0.01~0.02) [50,51] films, and are similar with the results from the Pt/Co/Ta [44] and W/CoTb/Pt [45] trilayers.…”

Section: Resultssupporting

confidence: 86%

“…Hall effect in Ir and the additive SOTs arising from the opposite spin Hall angles between Pt and Ta (or W) [44,45] . Based on θ SH = 2 e ℏ M s t F χ , the effective spin Hall angles of Pt/SmCo 5 /Ta, Pt/SmCo 5 /W and Pt/SmCo 5 /Ir can be obtained as 0.68, 0.53 and 0.29, respectively.…”

Section: Resultsmentioning

confidence: 99%

Rare‐Earth Permanent Magnet SmCo₅ for Chiral Interfacial Spin‐Orbitronics

Zhou

Wang

Zhang

et al. 2021

Adv Funct Materials

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“…Figure 1d shows that increasing the composition gradient leads to a decrease of the overall M s of the sample, which corresponds to the Co-rich part tendency in Fig. 1b , i.e., increasing the average Tb composition makes the sample approach the magnetic compensation point 8 , 9 . When δ arrives at 0.07, the sample is nearly compensated ( M s < 50 emu/cc), while the sample starts to show an in-plane magnetization component when exceeding δ = 0.07.…”

Section: Resultsmentioning

confidence: 79%

“…As a ferrimagnetic alloy, in which RE elements and TM elements are coupled anti-ferromagnetically, CoTb can exhibit robust PMA in a wide composition range 8 , 9 . To investigate the exact composition range of PMA, a series of Al (2 nm)/Co 1- a Tb a (6 nm)/Al (3 nm) films (see Fig.…”

Section: Resultsmentioning

confidence: 99%

Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with a vertical composition gradient

et al. 2021

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Current-induced spin-orbit torques (SOTs) are of interest for fast and energy-efficient manipulation of magnetic order in spintronic devices. To be deterministic, however, switching of perpendicularly magnetized materials by SOT requires a mechanism for in-plane symmetry breaking. Existing methods to do so involve the application of an in-plane bias magnetic field, or incorporation of in-plane structural asymmetry in the device, both of which can be difficult to implement in practical applications. Here, we report bias-field-free SOT switching in a single perpendicular CoTb layer with an engineered vertical composition gradient. The vertical structural inversion asymmetry induces strong intrinsic SOTs and a gradient-driven Dzyaloshinskii–Moriya interaction (g-DMI), which breaks the in-plane symmetry during the switching process. Micromagnetic simulations are in agreement with experimental results, and elucidate the role of g-DMI in the deterministic switching processes. This bias-field-free switching scheme for perpendicular ferrimagnets with g-DMI provides a strategy for efficient and compact SOT device design.

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“…The detailed configurations are summarized in Table 1. The logic output can be amplified by complementary metal oxide semiconductor (CMOS) and be written into the target memory unit by fast and energy efficient magnetic writing process, such as spin transfer torque (STT) [36], [37] or spin orbit torque (SOT) [38]- [40]. In these mechanisms, the change of current direction can work as logic function NOT.…”

Section: Implementation Of Reconfigurable Logic Operationmentioning

confidence: 99%

A Diode-Enhanced Scheme for Giant Magnetoresistance Amplification and Reconfigurable Logic

Jiang

Zhang

et al. 2020

IEEE Access

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Magnetoresistance (MR) effects have been intensively investigated and widely recognized as an effective path for realizing information sensing, storage, and processing. In particular, giant MR (GMR) effect discovered in ferromagnetic/nonmagnetic multilayers or junctions exhibits high magnetic-field sensitivity and has been successfully applied in magnetic sensors and hard disk drive (HDD) read heads. However, the relatively small MR ratio becomes the Achilles' Heel for its further application in high-reliability electronic systems. In this paper, we propose a scheme to amplify the GMR effect of a multilayer strip by utilizing the nonlinear transport property of a diode. MR ratio up to 6947% is obtained with a magnetic field as small as 50 Oe. A theoretical model is established to describe the amplification behavior and various factors influencing MR ratio are experimentally analyzed. Based on this scheme, reliable logic functions have been carried out, which can be reconfigured by changing the working current. Our work can be extended to enhance the MR effect of any two-terminal MR device and has the potential to build emerging highperformance computing systems.

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Enhanced Spin-Orbit Torque and Multilevel Current-Induced Switching in W/Co−Tb/Pt Heterostructure

Cited by 46 publications

References 42 publications

Rare‐Earth Permanent Magnet SmCo₅ for Chiral Interfacial Spin‐Orbitronics

Rare‐Earth Permanent Magnet SmCo₅ for Chiral Interfacial Spin‐Orbitronics

Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with a vertical composition gradient

A Diode-Enhanced Scheme for Giant Magnetoresistance Amplification and Reconfigurable Logic

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Enhanced Spin-Orbit Torque and Multilevel Current-Induced Switching in W/Co−Tb/Pt Heterostructure

Cited by 46 publications

References 42 publications

Rare‐Earth Permanent Magnet SmCo5 for Chiral Interfacial Spin‐Orbitronics

Rare‐Earth Permanent Magnet SmCo5 for Chiral Interfacial Spin‐Orbitronics

Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with a vertical composition gradient

A Diode-Enhanced Scheme for Giant Magnetoresistance Amplification and Reconfigurable Logic

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Product

Resources

About

Rare‐Earth Permanent Magnet SmCo₅ for Chiral Interfacial Spin‐Orbitronics

Rare‐Earth Permanent Magnet SmCo₅ for Chiral Interfacial Spin‐Orbitronics