scholarly journals Subterahertz spin pumping from an insulating antiferromagnet

Science ◽  
2020 ◽  
Vol 368 (6487) ◽  
pp. 160-165 ◽  
Author(s):  
Priyanka Vaidya ◽  
Sophie A. Morley ◽  
Johan van Tol ◽  
Yan Liu ◽  
Ran Cheng ◽  
...  
Keyword(s):  
Magnetic Moments ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Pure Spin ◽  
Spin Pumping ◽  
Hall Effects ◽  
Terahertz Frequencies ◽  
Platinum Layer ◽  
And Control ◽  
Spin Hall Effects

Spin-transfer torque and spin Hall effects combined with their reciprocal phenomena, spin pumping and inverse spin Hall effects (ISHEs), enable the reading and control of magnetic moments in spintronics. The direct observation of these effects remains elusive in antiferromagnetic-based devices. We report subterahertz spin pumping at the interface of the uniaxial insulating antiferromagnet manganese difluoride and platinum. The measured ISHE voltage arising from spin-charge conversion in the platinum layer depends on the chirality of the dynamical modes of the antiferromagnet, which is selectively excited and modulated by the handedness of the circularly polarized subterahertz irradiation. Our results open the door to the controlled generation of coherent, pure spin currents at terahertz frequencies.

Spin Pumping Induced Inverse Spin-Hall Effects in ${\rm La}_{0.7}{\rm Sr}_{0.3}{\rm MnO}_{3}$/Platinum Bilayer Film

2012 ◽  
Vol 48 (11) ◽  
pp. 3958-3960 ◽  
Author(s):  
G. Y. Luo ◽  
M. Y. Song ◽  
H. Y. Hung ◽  
Y. C. Chiu ◽  
J. Kwo ◽  
...  
Keyword(s):  
Bilayer Film ◽  
Spin Pumping ◽  
Hall Effects ◽  
Spin Hall Effects

scholarly journals Spin-transfer torque in nanoscale magnetic devices

2011 ◽  
Vol 369 (1951) ◽  
pp. 3617-3630 ◽  
Author(s):  
D. C. Ralph ◽  
Y.-T. Cui ◽  
L. Q. Liu ◽  
T. Moriyama ◽  
C. Wang ◽  
...  
Keyword(s):  
New York ◽  
Magnetic Moments ◽  
Critical Currents ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Torque ◽  
Single Shot ◽  
Cornell University ◽  
Magnetic Devices ◽  
Magnetic Switching

We discuss recent highlights from research at Cornell University, Ithaca, New York, regarding the use of spin-transfer torques to control magnetic moments in nanoscale ferromagnetic devices. We highlight progress on reducing the critical currents necessary to produce spin-torque-driven magnetic switching, quantitative measurements of the magnitude and direction of the spin torque in magnetic tunnel junctions, and single-shot measurements of the magnetic dynamics generated during thermally assisted spin-torque switching.

scholarly journals Dynamics of chiral solitons driven by polarized currents in monoaxial helimagnets

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Victor Laliena ◽  
Sebastian Bustingorry ◽  
Javier Campo
Keyword(s):  
Current Density ◽  
Steady Motion ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Applied Current ◽  
Applied Current Density ◽  
Magnetic Structures ◽  
And Control ◽  
Moriya Interaction ◽  
Chiral Solitons

AbstractChiral solitons are one dimensional localized magnetic structures that are metastable in some ferromagnetic systems with Dzyaloshinskii–Moriya interactions and/or uniaxial magnetic anisotropy. Though topological textures in general provide a very interesting playground for new spintronics phenomena, how to properly create and control single chiral solitons is still unclear. We show here that chiral solitons in monoaxial helimagnets, characterized by a uniaxial Dzyaloshinskii–Moriya interaction, can be stabilized with external magnetic fields. Once created, the soliton moves steadily in response to a polarized electric current, provided the induced spin-transfer torque has a dissipative (nonadiabatic) component. The structure of the soliton depends on the applied current density in such a way that steady motion exists only if the applied current density is lower than a critical value, beyond which the soliton is no longer stable.

Spin transfer torque ferromagnetic resonance induced spin pumping in the Fe/Pd bilayer system

2017 ◽  
Vol 95 (6) ◽  
Author(s):  
A. Kumar ◽  
S. Akansel ◽  
H. Stopfel ◽  
M. Fazlali ◽  
J. Åkerman ◽  
...  
Keyword(s):  
Ferromagnetic Resonance ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Pumping ◽  
Bilayer System

Spin-transfer torque in nonuniform magnetic structures

2017 ◽  
Author(s):  
T. Ono
Keyword(s):  
Magnetic Moments ◽  
Magnetic Domain ◽  
Dipole Interaction ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Magnetic Vortex ◽  
Magnetic Domains ◽  
Spin Configuration ◽  
Magnetic Structures ◽  
Ferromagnetic Disk

This chapter defines a magnetic domain wall (DW) as the transition region where the direction of magnetic moments gradually change between two neighbouring domains. It has been pointed out that ferromagnetic materials are not necessarily magnetized to saturation in the absence of an external magnetic field. Instead, they have magnetic domains, within each of which magnetic moments align. The formation of the magnetic domains is energetically favourable because this structure can lower the magnetostatic energy originating from the dipole–dipole interaction. A magnetic vortex realized in a ferromagnetic disk is a typical example of nonuniform magnetic structure. In very small ferromagnetic systems, where a curling spin configuration has been proposed to occur in place of domains, the formation of DWs is not energetically favored.

scholarly journals Spin-flip scattering engendered quantum spin torque in a Josephson junction

2019 ◽  
Vol 475 (2224) ◽  
pp. 20180775
Author(s):  
Subhajit Pal ◽  
Colin Benjamin
Keyword(s):  
Josephson Junction ◽  
Exchange Coupling ◽  
Magnetic Impurity ◽  
Magnetic Moments ◽  
Quantum Spin ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Spin Torque ◽  
Spin Flip ◽  
Quantum Mechanism

We examine a Josephson junction with two ferromagnets and a magnetic impurity sandwiched between two superconductors. In such ferromagnetic Josephson junctions, equilibrium spin torque exists only when ferromagnets are misaligned. This is explained via the ‘conventional’ mechanism of spin transfer torque, which owes its origin to the misalignment of two ferromagnets. However, we see surprisingly when the magnetic moments of the ferromagnets are aligned parallel or anti-parallel, there is a finite equilibrium spin torque due to the quantum mechanism of spin-flip scattering. We explore the properties of this unique spin-flip scattering-induced equilibrium quantum spin torque, especially its tunability via exchange coupling and phase difference across the superconductors.

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