Resonant tunneling via spin-polarized barrier states in a magnetic tunnel junction

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.

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Bolometric Properties of a Spin-Torque Diode Based on a Magnetic Tunnel Junction

Advances in Condensed Matter Physics ◽

10.1155/2019/5109765 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

G. D. Demin ◽

K. A. Zvezdin ◽

A. F. Popkov

Keyword(s):

Tunnel Junction ◽

Magnetic Tunnel Junction ◽

Nonuniform Heating ◽

Spin Torque ◽

Rectification Effect ◽

Wide Range ◽

Spin Polarized ◽

Potential Applications ◽

Dynamic Components ◽

Bolometric Effect

Spin caloritronics opens up a wide range of potential applications, one of which can be the thermoelectric rectification of a microwave signal by spin-diode structures. The bolometric properties of a spin-torque diode based on a magnetic tunnel junction (MTJ) in the presence of a thermal gradient through a tunnel junction are discussed. Theoretical estimates of the static and dynamic components of the microwave sensitivity of the spin-torque diode, related to thermoelectric tunnel magneto-Seebeck effect and the thermal transfer of spin angular momentum in the MTJ under nonuniform heating, are presented. Despite the fact that the thermal contribution to the microwave sensitivity of the spin-torque diode is found to be relatively small in relation to the rectification effect related to the modulation of the MTJ resistance by a microwave spin-polarized current, nevertheless, the considered bolometric effect can be successfully utilized in some real-world microwave applications.

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Picosecond Optospintronic Tunnel Junctions for Non-volatile Photonic Memories

10.21203/rs.3.rs-132635/v1 ◽

2021 ◽

Author(s):

Luding Wang ◽

Houyi Cheng ◽

Pingzhi Li ◽

Yang Liu ◽

Youri van Hees ◽

...

Keyword(s):

Tunnel Junction ◽

Tunnel Junctions ◽

Magnetic Tunnel Junction ◽

Data Access ◽

Building Blocks ◽

Spin Transfer Torque ◽

Time Resolved ◽

Physical Constraints ◽

Spin Polarized ◽

All Optical

Abstract Perpendicular magnetic tunnel junctions are one of the building blocks for spintronic memories, which allow fast nonvolatile data access, offering substantial potentials to revolutionize the mainstream computing architecture. However, conventional switching mechanisms of such devices are fundamentally hindered by spin polarized currents, either spin transfer torque or spin orbit torque with spin precession time limitation and excessive power dissipation. These physical constraints significantly stimulate the advancement of modern spintronics. Here, we report an optospintronic tunnel junction using a photonic-spintronic combination. This composite device incorporates an all-optically switchable Co/Gd bilayer coupled to a CoFeB/MgO-based perpendicular magnetic tunnel junction by the Ruderman-Kittel-Kasuya-Yosida interaction. A picosecond all-optical operation of the optospintronic tunnel junction is explicitly confirmed by time-resolved measurements. Moreover, the device shows a considerable tunnel magnetoresistance and thermal stability. This proof-of-concept device represents an essential step towards ultrafast photonic memories with THz data access, as well as ultralow power consumption.

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Large magnetoresistance and spin-polarized photocurrent in La2/3Sr1/3MnO3(Co)/quaterthiophene/La2/3Sr1/3MnO3 organic magnetic tunnel junctions

Journal of Materials Chemistry C ◽

10.1039/c8tc06547k ◽

2019 ◽

Vol 7 (14) ◽

pp. 4079-4088 ◽

Cited By ~ 9

Author(s):

Xuefei Han ◽

Wenbo Mi ◽

Xiaocha Wang

Keyword(s):

Tunnel Junction ◽

Tunnel Junctions ◽

Spin Injection ◽

Magnetic Tunnel Junctions ◽

Magnetic Tunnel Junction ◽

Tunneling Magnetoresistance ◽

Spin Polarized

Large tunneling magnetoresistance, perfect spin injection and fully spin-polarized photocurrent are realized in a LSMO/T4/LSMO organic magnetic tunnel junction.

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Spin-polarized inelastic electron tunneling spectroscopy of a molecular magnetic tunnel junction

Applied Physics Letters ◽

10.1063/1.2360908 ◽

2006 ◽

Vol 89 (15) ◽

pp. 153105 ◽

Cited By ~ 30

Author(s):

Wenyong Wang ◽

Curt A. Richter

Keyword(s):

Tunnel Junction ◽

Electron Tunneling ◽

Magnetic Tunnel Junction ◽

Tunneling Spectroscopy ◽

Inelastic Electron ◽

Inelastic Electron Tunneling Spectroscopy ◽

Spin Polarized ◽

Inelastic Electron Tunneling ◽

Electron Tunneling Spectroscopy

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Characteristic Length Scale for Spin Polarized Tunneling in Langmuir-Blodgett Molecular Magnetic Tunnel Junction

IEEE Transactions on Magnetics ◽

10.1109/tmag.2009.2025253 ◽

2009 ◽

Vol 45 (10) ◽

pp. 3962-3964

Author(s):

Dongping Liu ◽

Yibin Hu ◽

Hong Guo ◽

X.F. Han

Keyword(s):

Tunnel Junction ◽

Characteristic Length ◽

Magnetic Tunnel Junction ◽

Length Scale ◽

Characteristic Length Scale ◽

Langmuir Blodgett ◽

Spin Polarized ◽

Spin Polarized Tunneling

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Giant thermal spin-torque–assisted magnetic tunnel junction switching

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1507084112 ◽

2015 ◽

Vol 112 (21) ◽

pp. 6585-6590 ◽

Cited By ~ 47

Author(s):

Aakash Pushp ◽

Timothy Phung ◽

Charles Rettner ◽

Brian P. Hughes ◽

See-Hun Yang ◽

...

Keyword(s):

Tunnel Junction ◽

Magnetic Tunnel Junction ◽

Spin Transfer Torque ◽

Temperature Gradients ◽

Large Temperature ◽

Spin Torque ◽

Tunneling Conductance ◽

Zero Bias ◽

Spin Polarized ◽

Spin Torques

Spin-polarized charge currents induce magnetic tunnel junction (MTJ) switching by virtue of spin-transfer torque (STT). Recently, by taking advantage of the spin-dependent thermoelectric properties of magnetic materials, novel means of generating spin currents from temperature gradients, and their associated thermal-spin torques (TSTs), have been proposed, but so far these TSTs have not been large enough to influence MTJ switching. Here we demonstrate significant TSTs in MTJs by generating large temperature gradients across ultrathin MgO tunnel barriers that considerably affect the switching fields of the MTJ. We attribute the origin of the TST to an asymmetry of the tunneling conductance across the zero-bias voltage of the MTJ. Remarkably, we estimate through magneto-Seebeck voltage measurements that the charge currents that would be generated due to the temperature gradient would give rise to STT that is a thousand times too small to account for the changes in switching fields that we observe.

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Magnetization switching by spin-polarized current in low-resistance magnetic tunnel junction with MgO [001] barrier

IEEE Transactions on Magnetics ◽

10.1109/tmag.2005.854816 ◽

2005 ◽

Vol 41 (10) ◽

pp. 2633-2635 ◽

Cited By ~ 32

Author(s):

H. Kubota ◽

A. Fukushima ◽

Y. Ootani ◽

S. Yuasa ◽

K. Ando ◽

...

Keyword(s):

Tunnel Junction ◽

Magnetic Tunnel Junction ◽

Magnetization Switching ◽

Low Resistance ◽

Spin Polarized

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Spin torque in uniform magnetization

10.1093/oso/9780198787075.003.0020 ◽

2017 ◽

Author(s):

Y. Suzuki

Keyword(s):

Barrier Layer ◽

Tunnel Junction ◽

Spin Current ◽

Magnetic Tunnel Junction ◽

Spin Torque ◽

Free Layer ◽

Nonmagnetic Metal ◽

Uniform Magnetization ◽

Spin Polarized ◽

Ferromagnetic Layers

This chapter discusses the effects of a spin current injected into a uniformly magnetized ferromagnetic cell. The junction consists of two ferromagnetic layers separated by a nonmagnetic metal interlayer or insulating barrier layer. With a nonmagnetic metal interlayer, the junction is called a giant magnetoresistive nanopillar, and with an insulating barrier layer a magnetic-tunnel junction. When charge current is passed through this device, the electrons are first spin polarized by the fixed layer and spin-polarized current is then injected into the free layer through the nonmagnetic interlayer. This spin current interacts with the spins in the host material by an exchange interaction and exerts a torque. If the exerted torque is large enough, magnetization in the free layer is reversed or continuous precession is excited.

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