Significant reduction of coercivity without reduction of tunneling magnetoresistance ratio of CoFeB∕MgO∕CoFeB-based magnetic tunnel junction using sandwich-structured free layer

2007 ◽  
Vol 91 (17) ◽  
pp. 172507 ◽  
Author(s):  
Young-suk Choi ◽  
Koji Tsunekawa
Author(s):  
Nafeesa Rahman ◽  
Rachid Sbiaa

The transfer of spin angular momentum from a spin polarized current provides an efficient way of reversing the magnetization direction of the free layer of the magnetic tunnel junction (MTJ), and while faster reversal will reduce the switching energy, this in turn will lead to low power consumption. In this work, we propose a design where a spin torque oscillator (STO) is integrated with a conventional magnetic tunnel junction (MTJ) which will assist in the ultrafast reversal of the magnetization of the free layer of the MTJ. The structure formed (MTJ stacked with STO), will have the free layer of the MTJ sandwiched between two spin polarizer layers, one with a fixed magnetization direction perpendicular to film plane (main static polarizer) and the other with an oscillatory magnetization (dynamic polarizer). The static polarizer is the fixed layer of the MTJ itself and the dynamic polarizer is the free layer of the STO.


2021 ◽  
Author(s):  
Aijaz Lone ◽  
Selma Amara ◽  
Hossein Fariborzi

The present work discusses the proposal of a spintronic neuromorphic system with spin orbit torque driven domain wall motion-based neuron and synapse. We propose a voltage-controlled magnetic anisotropy domain wall motion based magnetic tunnel junction neuron. We investigate how the electric field at the gate (pinning site), generated by the voltage signals from pre-neurons, modulates the domain wall motion, which reflects in the non-linear switching behaviour of neuron magnetization. For the implementation of synaptic weights, we propose 3-terminal MTJ with stochastic domain wall motion in the free layer. We incorporate intrinsic pinning effects by creating triangular notches on the sides of the free layer. The pinning of domain wall and intrinsic thermal noise of device lead to the stochastic behaviour of domain wall motion. The control of this stochasticity by the spin orbit torque is shown to realize the potentiation and depression of the synaptic weight. The micromagnetics and spin transport studies in synapse and neuron are carried out by developing a coupled micromagnetic Non-Equilibrium Green’s Function (<i>MuMag-NEGF</i>) model. The minimization of the writing current pulse width by leveraging the thermal noise and demagnetization energy is also presented. Finally, we discuss the implementation of digit recognition by the proposed system using a spike time dependent algorithm.


Author(s):  
Marco Mansueto ◽  
Antoine Chavent ◽  
Ricardo Sousa ◽  
Liliana D. Buda-Prejbeanu ◽  
Ioan L. Prejbeanu ◽  
...  

2019 ◽  
Vol 11 (19) ◽  
pp. 17647-17653 ◽  
Author(s):  
Jiaqi Zhou ◽  
Junfeng Qiao ◽  
Chun-Gang Duan ◽  
Arnaud Bournel ◽  
Kang L. Wang ◽  
...  

2014 ◽  
Vol 115 (17) ◽  
pp. 17B902 ◽  
Author(s):  
Faisal A. Shah ◽  
Vijay K. Sankar ◽  
Peng Li ◽  
Gyorgy Csaba ◽  
Eugene Chen ◽  
...  

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