From giant magnetoresistance to current-induced switching by spin transfer

2005 ◽  
Vol 72 (2) ◽  
Author(s):  
J. Barnaś ◽  
A. Fert ◽  
M. Gmitra ◽  
I. Weymann ◽  
V. K. Dugaev
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Transfer

Introduction of spin torques

2017 ◽  
Author(s):  
T. Kimura
Keyword(s):  
Angular Momentum ◽  
Giant Magnetoresistance ◽  
Spontaneous Magnetization ◽  
Magnetic Domain ◽  
Magnetic Multilayers ◽  
Transfer Effect ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Angular Momentum ◽  
Spin Torques

This chapter discusses the spin-transfer effect, which is described as the transfer of the spin angular momentum between the conduction electrons and the magnetization of the ferromagnet that occurs due to the conservation of the spin angular momentum. L. Berger, who introduced the concept in 1984, considered the exchange interaction between the conduction electron and the localized magnetic moment, and predicted that a magnetic domain wall can be moved by flowing the spin current. The spin-transfer effect was brought into the limelight by the progress in microfabrication techniques and the discovery of the giant magnetoresistance effect in magnetic multilayers. Berger, at the same time, separately studied the spin-transfer torque in a system similar to Slonczewski’s magnetic multilayered system and predicted spontaneous magnetization precession.

Area dependence of high-frequency spin-transfer resonance in giant magnetoresistance contacts up to 300nm diameter

2006 ◽  
Vol 88 (11) ◽  
pp. 112507 ◽  
Author(s):  
F. B. Mancoff ◽  
N. D. Rizzo ◽  
B. N. Engel ◽  
S. Tehrani
Keyword(s):  
High Frequency ◽  
Giant Magnetoresistance ◽  
Spin Transfer

scholarly journals A New Circuit Model for Spin-Torque Oscillator Including Perpendicular Torque of Magnetic Tunnel Junction

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hyein Lim ◽  
Sora Ahn ◽  
Miryeon Kim ◽  
Seungjun Lee ◽  
Hyungsoon Shin
Keyword(s):  
Tunnel Junction ◽  
Giant Magnetoresistance ◽  
New Technology ◽  
Magnetic Tunnel Junction ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Torque ◽  
Mean Oscillation ◽  
Proposed Model ◽  
Level Model

Spin-torque oscillator (STO) is a promising new technology for the future RF oscillators, which is based on the spin-transfer torque (STT) effect in magnetic multilayered nanostructure. It is expected to provide a larger tunability, smaller size, lower power consumption, and higher level of integration than the semiconductor-based oscillators. In our previous work, a circuit-level model of the giant magnetoresistance (GMR) STO was proposed. In this paper, we present a physics-based circuit-level model of the magnetic tunnel junction (MTJ)-based STO. MTJ-STO model includes the effect of perpendicular torque that has been ignored in the GMR-STO model. The variations of three major characteristics, generation frequency, mean oscillation power, and generation linewidth of an MTJ-STO with respect to the amount of perpendicular torque, are investigated, and the results are applied to our model. The operation of the model was verified by HSPICE simulation, and the results show an excellent agreement with the experimental data. The results also prove that a full circuit-level simulation with MJT-STO devices can be made with our proposed model.

scholarly journals DATA STORAGE: REVIEW OF HEUSLER COMPOUNDS

SPIN ◽  
2012 ◽  
Vol 02 (04) ◽  
pp. 1230006 ◽  
Author(s):  
ZHAOQIANG BAI ◽  
LEI SHEN ◽  
GUCHANG HAN ◽  
YUAN PING FENG
Keyword(s):  
Data Storage ◽  
Giant Magnetoresistance ◽  
Functional Materials ◽  
Recent Decade ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Magnetic Data ◽  
Heusler Compounds ◽  
Storage Devices ◽  
The Family

In the recent decade, the family of Heusler compounds has attracted tremendous scientific and technological interest in the field of spintronics. This is essentially due to their exceptional magnetic properties, which qualify them as promising functional materials in various data-storage devices, such as giant-magnetoresistance spin valves, magnetic tunnel junctions, and spin-transfer torque devices. In this article, we provide a comprehensive review on the applications of the Heusler family in magnetic data storage. In addition to their important roles in the performance improvement of these devices, we also try to point out the challenges as well as possible solutions, of the current Heusler-based devices. We hope that this review would spark further investigation efforts into efficient incorporation of this eminent family of materials into data storage applications by fully arousing their intrinsic potential.

Spin Valves in Microelectronics. Review

2021 ◽  
Vol 26 (1) ◽  
pp. 7-29
Author(s):  
Iu.A. Iusipova ◽  
◽  
A.I. Popov ◽  
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valve ◽  
Random Access ◽  
Cmos Technology ◽  
Work Conditions ◽  
Spin Transfer ◽  
Boolean Logic ◽  
Spin Valves ◽  
Computing Systems ◽  
Technology Scaling

The base element of micromagnetic devices are the layered spin-valve structures. Small sizes, compatibility with the CMOS technology, scaling ability and various work conditions make the spin-valve structures a universal component of modern microelectronics. The purpose of present work is the analysis, systematization and generalization of the data of the work theoretical bases, experimental data and the application of spin valves. In the review, the hard disc drives, random-access magnetoresistive memory, the spin-transfer nano-oscillators, the magnetic biosensors, as well as various computing systems, operating on the principles of stochastic and deterministic logic, have been considered. The key theoretical works devoted to giant magnetoresistance and spin transfer have been used. The data on various types of the hard-disc readheads have been systematized, their architecture and parameters have been compared, and it has been shown how modern scientific research of nanomagnetic phenomena accelerates the growth rate of the recording density. The analysis of modern research devoted to magnetoresistive random access memory has been carried out. The problems of energy efficiency and increasing the degree of the integration for these devices have been discussed. The latest achievements in the field of materials, geometry and the properties of the spin-transfer nano-oscillators, as well as the problems and prospects for the development of this technology have been considered. The analysis of theoretical and experimental works, in which the spin-gate structures have been used to perform the logical operations of Boolean and non-Boolean logic, has been carried out. It has been shown how the probabilistic nature of the unstable switching of spin gates is used in the op-eration of the unconventional computing systems, namely, neuromorphic or Bayesian networks. The principles of operation of the spin valves as magnetic biosensors have been considered and the advantages of their application have been discussed.

scholarly journals Heterostructures for Realizing Magnon-Induced Spin Transfer Torque

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
P. B. Jayathilaka ◽  
M. C. Monti ◽  
J. T. Markert ◽  
Casey W. Miller
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valve ◽  
Building Blocks ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Buffer Layers ◽  
High Quality ◽  
Spacer Layer Thickness ◽  
Spacer Layer ◽  
Structural And Magnetic Properties

This work reports efforts fabricating heterostructures of different materials relevant for the realization of magnon-induced spin transfer torques. We find the growth of high-quality magnetite on MgO substrates to be straightforward, while using transition metal buffer layers of Fe, Cr, Mo, and Nb can alter the structural and magnetic properties of the magnetite. Additionally, we successfully fabricated and characterized Py/Cr/Fe3O4and Fe3O4/Cr/Fe3O4spin valve structures. For both, we observe a relatively small giant magnetoresistance and confirm an inverse dependence on spacer layer thickness. Thus, we have shown certain materials combinations that may form the heterostructures that are the building blocks necessary to achieve magnon-induced spin transfer torque devices.

scholarly journals Spintronics - A Dive Into the Future

2020 ◽  
pp. 433-440
Author(s):  
Shahzeb Hussain ◽  
Shaayan Hussain
Keyword(s):  
Giant Magnetoresistance ◽  
New Technologies ◽  
Random Access ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Effective Control ◽  
Hard Drives ◽  
The Road ◽  
A Charge ◽  
Dependent Transport

We already know that electrons have a charge along with a spin, but until recently, these two have been considered separately. The motion of electric charge is considered as the heart of electronic circuits, and the flow of electron spin plays a crucial role in spintronic circuits. Adding the spin degree of freedom provides new capabilities, new effects, and new functionalities. It all started with the discovery of the Giant Magnetoresistance (GMR) in 1988, which opened the road to an effective control of the motion of the electron charges by focusing on their spin through the orientation of magnetization. Today, spintronics has entered into almost every household as the read sensors for the hard drives present in every desktop and most laptops. Magnetic Random Access Memory (MRAM) and Spin Transfer Torque (STT) RAM are replacing Static RAM where ultra-dense memories are not required. Soon these spintronic memories will penetrate the cell phone market because they offer lower power and are non-volatile. The potential held by Spintronics is very promising for new advancements in science and technology in the 21st century. This paper discusses the evolution of spintronics from the initial research of spin-dependent transport in ferromagnetic materials to the discovery of the giant magnetoresistance and to the most recent advances. Today, this field of research is extending considerably, with very encouraging new technologies like the phenomena of spin transfer, molecular spintronics, nanoscale spintronics, and single-electron spintronics.

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