scholarly journals Domain wall-magnetic tunnel junction spin–orbit torque devices and circuits for in-memory computing

2021 ◽  
Vol 118 (11) ◽  
pp. 112401
Author(s):  
Mahshid Alamdar ◽  
Thomas Leonard ◽  
Can Cui ◽  
Bishweshwor P. Rimal ◽  
Lin Xue ◽  
...  
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Magnetic Tunnel Junction ◽  
Spin Orbit

scholarly journals Voltage Controlled Domain Wall Motion based Neuron and Stochastic Magnetic Tunnel Junction Synapse for Neuromorphic Computing Applications

2021 ◽  
Author(s):  
Aijaz Lone ◽  
Selma Amara ◽  
Hossein Fariborzi
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Thermal Noise ◽  
Wall Motion ◽  
Magnetic Tunnel Junction ◽  
Domain Wall Motion ◽  
Spin Orbit ◽  
Free Layer ◽  
Digit Recognition ◽  
Transport Studies

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.

scholarly journals Voltage Controlled Domain Wall Motion based Neuron and Stochastic Magnetic Tunnel Junction Synapse for Neuromorphic Computing Applications

2021 ◽  
Author(s):  
Aijaz Lone ◽  
Selma Amara ◽  
Hossein Fariborzi
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Thermal Noise ◽  
Wall Motion ◽  
Magnetic Tunnel Junction ◽  
Domain Wall Motion ◽  
Spin Orbit ◽  
Free Layer ◽  
Digit Recognition ◽  
Transport Studies

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.

scholarly journals Nanoscale domain wall devices with magnetic tunnel junction read and write

2021 ◽  
Vol 4 (6) ◽  
pp. 392-398 ◽  
Author(s):  
E. Raymenants ◽  
O. Bultynck ◽  
D. Wan ◽  
T. Devolder ◽  
K. Garello ◽  
...  
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Magnetic Tunnel Junction ◽  
Domain Wall Devices

A domain wall-magnetic tunnel junction artificial synapse with notched geometry for accurate and efficient training of deep neural networks

2021 ◽  
Vol 118 (20) ◽  
pp. 202405
Author(s):  
Samuel Liu ◽  
T. Patrick Xiao ◽  
Can Cui ◽  
Jean Anne C. Incorvia ◽  
Christopher H. Bennett ◽  
...  
Keyword(s):  
Neural Networks ◽  
Domain Wall ◽  
Tunnel Junction ◽  
Deep Neural Networks ◽  
Magnetic Tunnel Junction ◽  
Artificial Synapse

scholarly journals Concentric 360° domain wall nesting in magnetic tunnel junction films: a Lorentz TEM study

2015 ◽  
Vol 48 (5) ◽  
pp. 055001 ◽  
Author(s):  
K J O’Shea ◽  
K Rode ◽  
H Kurt ◽  
D McGrouther ◽  
D A MacLaren
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Magnetic Tunnel Junction

Non-volatile logic device based on domain-wall motion in a biaxial magnetic tunnel junction

2021 ◽  
Vol 60 (2) ◽  
pp. 020904
Author(s):  
Shuping Li ◽  
Jialin Cai ◽  
Wenxing Lv ◽  
Like Zhang ◽  
Shiheng Liang ◽  
...  
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Wall Motion ◽  
Magnetic Tunnel Junction ◽  
Domain Wall Motion ◽  
Logic Device

scholarly journals Anomalous and spin Hall effects in a magnetic tunnel junction with Rashba spin-orbit coupling

2013 ◽  
Vol 103 (3) ◽  
pp. 032406 ◽  
Author(s):  
A. V. Vedyayev ◽  
M. S. Titova ◽  
N. V. Ryzhanova ◽  
M. Ye. Zhuravlev ◽  
E. Y. Tsymbal
Keyword(s):  
Tunnel Junction ◽  
Magnetic Tunnel Junction ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Rashba Spin ◽  
Hall Effects ◽  
Spin Hall Effects

MAGNETIC RACE-TRACK — A NOVEL STORAGE CLASS SPINTRONIC MEMORY

2008 ◽  
Vol 22 (01n02) ◽  
pp. 117-118 ◽  
Author(s):  
STUART PARKIN
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Domain Walls ◽  
Magnetic Tunnel Junction ◽  
Domain Wall Motion ◽  
Wall Structure ◽  
Micromagnetic Simulations ◽  
Confining Potential ◽  
Current Pulses ◽  
Race Track

A proposal for a novel storage-class memory is described in which magnetic domains are used to store information in a "magnetic race-track".1 The magnetic race-track shift register storage memory promises a solid state memory with storage capacities and cost rivaling that of magnetic disk drives but with much improved performance and reliability. The magnetic race track is comprised of tall columns of magnetic material arranged perpendicularly to the surface of a silicon wafer. The domains are moved up and down the race-track by nanosecond long current pulses using the phenomenon of spin momentum transfer. The domain walls in the magnetic race-track are read using magnetic tunnel junction magnetoresistive sensing devices arranged in the silicon substrate. Recent progress in developing magnetic tunnel junction devices with giant tunneling magnetoresistance exceeding 350% at room temperature will be mentioned.2 Experiments exploring the current induced motion and depinning of domain walls in magnetic nano-wires with artificial pinning sites will be discussed. The domain wall structure, whether vortex or transverse, and the magnitude of the pinning potential is shown to have surprisingly little effect on the current driven dynamics of the domain wall motion.3 By contrast the motion of DWs under nanosecond long current pulses is surprisingly sensitive to their length.4 In particular, we find that the probability of dislodging a DW, confined to a pinning site in a permalloy nanowire, oscillates with the length of the current pulse, with a period of just a few nanoseconds. Using an analytical model and micromagnetic simulations we show that this behaviour is connected to a current induced oscillatory motion of the DW. The period is determined by the DW mass and the curvature of the confining potential. When the current is turned off during phases of the DW motion when the DW has enough momentum, there is a boomerang effect that can drive the DW out of the confining potential in the opposite direction to the flow of spin angular momentum. Note from Publisher: This article contains the abstract only.

Anomalous switching in submicrometer magnetic tunnel junction arrays arising from magnetic vortex and domain wall pinning

2004 ◽  
Vol 96 (3) ◽  
pp. 1748-1750 ◽  
Author(s):  
Wanjun Park ◽  
I. J. Hwang ◽  
Taewan Kim ◽  
K. J. Lee ◽  
Young Keun Kim
Keyword(s):  
Domain Wall ◽  
Tunnel Junction ◽  
Magnetic Tunnel Junction ◽  
Magnetic Vortex ◽  
Domain Wall Pinning ◽  
Junction Arrays
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