Switching Current Density of Perpendicular Magnetization by Spin-Orbit Torque

Author(s):  
Lijun Zhu ◽  
D. C. Ralph ◽  
R. A. Buhrman
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Doo Hyung Kang ◽  
Mincheol Shin

AbstractRecently, magnetic tunnel junctions (MTJs) with shape perpendicular magnetic anisotropy (S-PMA) have been studied extensively because they ensure high thermal stability at junctions smaller than 20 nm. Furthermore, spin-transfer torque (STT) and spin-orbit torque (SOT) hybrid switching, which guarantees fast magnetization switching and deterministic switching, has recently been achieved in experiments. In this study, the critical switching current density of the MTJ with S-PMA through the interplay of STT and SOT was investigated using theoretical and numerical methods. As the current density inducing SOT ($$J_{\text {SOT}}$$ J SOT ) increases, the critical switching current density inducing STT ($$J_{\text {STT,c}}$$ J STT,c ) decreases. Furthermore, for a given $$J_{\text {SOT}}$$ J SOT , $$J_{\text {STT,c}}$$ J STT,c increases with increasing thickness, whereas $$J_{\text {STT,c}}$$ J STT,c decreases as the diameter increases. Moreover, $$J_{\text {STT,c}}$$ J STT,c in the plane of thickness and spin-orbit field-like torque ($$\beta$$ β ) was investigated for a fixed $$J_{\text {SOT}}$$ J SOT and diameter. Although $$J_{\text {STT,c}}$$ J STT,c decreases with increasing $$\beta$$ β , $$J_{\text {STT,c}}$$ J STT,c slowly increases with increasing thickness and increasing $$\beta$$ β . The power consumption was investigated as a function of thickness and diameter at the critical switching current density. Experimental confirmation of these results using existing experimental techniques is anticipated.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Kangkang Meng ◽  
Jun Miao ◽  
Xiaoguang Xu ◽  
Yong Wu ◽  
Jiaxing Xiao ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuejie Xie ◽  
Xiaonan Zhao ◽  
Yanan Dong ◽  
Xianlin Qu ◽  
Kun Zheng ◽  
...  

AbstractProgrammable magnetic field-free manipulation of perpendicular magnetization switching is essential for the development of ultralow-power spintronic devices. However, the magnetization in a centrosymmetric single-layer ferromagnetic film cannot be switched directly by passing an electrical current in itself. Here, we demonstrate a repeatable bulk spin-orbit torque (SOT) switching of the perpendicularly magnetized CoPt alloy single-layer films by introducing a composition gradient in the thickness direction to break the inversion symmetry. Experimental results reveal that the bulk SOT-induced effective field on the domain walls leads to the domain walls motion and magnetization switching. Moreover, magnetic field-free perpendicular magnetization switching caused by SOT and its switching polarity (clockwise or counterclockwise) can be reversibly controlled in the IrMn/Co/Ru/CoPt heterojunctions based on the exchange bias and interlayer exchange coupling. This unique composition gradient approach accompanied with electrically controllable SOT magnetization switching provides a promising strategy to access energy-efficient control of memory and logic devices.


Nanoscale ◽  
2021 ◽  
Author(s):  
Chao Sun ◽  
Yiyi Jiao ◽  
Chao Zuo ◽  
Xin Hu ◽  
Ying Tao ◽  
...  

In order to maintain thermal stability of SOT devices with nanoscale size, it is desirable to achieve current induced magnetic switching in magnetic materials with high perpendicular anisotropy. In the...


2020 ◽  
Author(s):  
Min-Gu Kang ◽  
Jong-Guk Choi ◽  
Jimin Jeong ◽  
Jae Yeol Park ◽  
Hyeon-Jong Park ◽  
...  

Abstract Spin-orbit coupling effect in structures with broken inversion symmetry, known as the Rashba effect, facilitates spin-orbit torques (SOTs) in heavy metal/ferromagnet/oxide structures, along with the spin Hall effect. Electric-field control of the Rashba effect is established for semiconductor interfaces, but it is challenging in structures involving metals owing to the screening effect. Here, we report that the Rashba effect in Pt/Co/AlOx structures is laterally modulated by electric voltages, generating out-of-plane SOTs. This enables field-free switching of the perpendicular magnetization and electrical control of the switching polarity. Changing the gate oxide reverses the sign of out-of-plane SOT while maintaining the same sign of voltage-controlled magnetic anisotropy, which confirms the Rashba effect at the Co/oxide interface is a key ingredient of the electric-field modulation. The electrical control of SOT switching polarity in a reversible and non-volatile manner can be utilized for programmable logic operations in spintronic logic-in-memory devices.


2019 ◽  
Vol 11 (42) ◽  
pp. 39369-39375 ◽  
Author(s):  
Baoshan Cui ◽  
Hao Wu ◽  
Dong Li ◽  
Seyed Armin Razavi ◽  
Di Wu ◽  
...  

2010 ◽  
Vol 24 (07) ◽  
pp. 649-656
Author(s):  
XI FU ◽  
GUANGHUI ZHOU

We investigate theoretically the spin current and spin current induced electric field in a weak Rashba spin-orbit coupling quantum wire (QW) using a definition for spin current by means of scattering matrix. It is found that there exists two non-zero linear spin current density elements which have oscillation peaks at the center of QW and their strengths can be changed by the number of propagation modes and Rashba constant, respectively. Moreover, the spin current induced electric field has also been calculated and its strength is measurable with present technology with which can be used to detect spin current.


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