Optical out-of-plane spin polarization and charge conductivities in spin-orbit-coupled systems in the presence of an in-plane magnetic field

2010 ◽  
Vol 74 (1) ◽  
pp. 19-25 ◽  
Author(s):  
C. M. Wang ◽  
M. Q. Pang
Keyword(s):  
Magnetic Field ◽  
Spin Polarization ◽  
Coupled Systems ◽  
Spin Orbit ◽  
Out Of Plane

scholarly journals Observation of anti-damping spin-orbit torques generated by in-plane and out-of-plane spin polarizations in MnPd3

2021 ◽  
Author(s):  
Mahendra DC ◽  
Ding-Fu Shao ◽  
Vincent Hou ◽  
Patrick Quarterman ◽  
Ali Habiboglu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
External Magnetic Field ◽  
Spin Polarization ◽  
Density Functional ◽  
Ferromagnetic Layer ◽  
Magnetic Memory ◽  
Spin Orbit ◽  
Logic Devices ◽  
Out Of Plane

Abstract High spin-orbit torques (SOTs) generated by topological materials and heavy metals interfaced with a ferromagnetic layer show promise for next generation magnetic memory and logic devices. SOTs generated from the in-plane spin polarization along y-axis originated by the spin Hall and Edelstein effects can switch magnetization collinear with the spin polarization in the absence of external magnetic fields. However, an external magnetic field is required to switch the magnetization along x and z-axes via SOT generated by y-spin polarization. Here, we present that the above limitation can be circumvented by unconventional SOT in magnetron-sputtered thin film MnPd3. In addition to the conventional in-plane anti-damping-like torque due to the y-spin polarization, out-of-plane and in-plane anti-damping-like torques originating from z-spin and x-spin polarizations, respectively have been observed at room temperature. The spin torque efficiency (θ_y) corresponding to the y-spin polarization from MnPd3 thin films grown on thermally oxidized silicon substrate and post annealed at 400 ℃ is 0.34 - 0.44 while the spin conductivity (σ_zx^y) is ~ 5.70 – 7.30× 105 ℏ⁄2e Ω-1m-1. Remarkably, we have demonstrated complete external magnetic field-free switching of perpendicular Co layer via unconventional out-of-plane anti-damping-like torque from z-spin polarization. Based on the density functional theory calculations, we determine that the observed x- and z- spin polarizations with the in-plane charge current are due to the low symmetry of the (114) oriented MnPd3 thin films. Taken together, the new material reported here provides a path to realize a practical spin channel in ultrafast magnetic memory and logic devices.

SPIN-DEPENDENT ELECTRON TRANSPORT THROUGH A THREE-TERMINAL MESOSCOPIC SPIN-ORBIT COUPLED SYSTEMS

2013 ◽  
Vol 27 (07) ◽  
pp. 1361003
Author(s):  
ZHONGHUI XU ◽  
XIANBO XIAO ◽  
YUGUANG CHEN
Keyword(s):  
Electron Transport ◽  
Spin Polarization ◽  
Function Method ◽  
Structural Parameters ◽  
Coupled Systems ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Wide Region ◽  
Rashba Spin ◽  
Electron Transport Properties

We studied theoretically the spin-dependent electron transport properties of a three-terminal nanostructure proposed by Xiao and Chen [J. Appl. Phys.1, 108 (2010)]. The spin-resolved recursive Green's function method is used to calculate the three-terminal spin-polarization. We focus on the influence both of the structural parameters and Rashba spin–orbit coupling (SOC) strength in the investigated system. It is shown that the spin-polarization is still a reasonable value for being observable in experiment with small Rashba SOC strength and longer length of the wide region in the investigated system. The underlying physics is revealed to originate from the effect of SOC-induced effective magnetic field at the structure-induced Fano resonance. This length of the middle wide region in three-terminal nanostructure can be more easily fabricated experimentally.

REEXAMINATION OF SPIN TRANSPORT THROUGH A DOUBLE-δ MAGNETIC BARRIER WITH SPIN-ORBIT INTERACTIONS

2009 ◽  
Vol 23 (30) ◽  
pp. 3631-3642
Author(s):  
CAIHUA BI ◽  
FENG ZHAI
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Spin Polarization ◽  
Energy Region ◽  
Spin Transport ◽  
Inhomogeneous Magnetic Field ◽  
Pure Spin ◽  
Spin Orbit ◽  
Spin Orbit Interactions ◽  
The Magnetic Field

We revisit the properties of spin transport through a semiconductor 2DEG system subjected to the modulation of both a ferromagnetic metal (FM) stripe on top and the Rashba and Dresselhaus spin-orbit interactions (SOIs). The FM stripe has a magnetization along the transporting direction and generates an inhomogeneous magnetic field in the 2DEG plane which is taken as a double-δ shape. It is found that the spin polarization of this system generated from a spin-unpolarized injection can be remarkable only within a low Fermi energy region and is not more than 30% for the parameters available in current experiments. In this energy region, both the magnitude and the orientation of the spin polarization can be tuned by the Rashba strength, the Dresselhaus strength, and the magnetic field strength. The magnetization reversal of the FM stripe cannot result in a change of the conductance, but can rotate the orientation of the spin polarization. The results are in contrast to those in [ J. Phys.: Condens. Matter15 (2003) L31] where a pure spin state for incident electrons is artificially assumed.

Nuclear spin polarization by out-of-plane spin injection from ferromagnet into an InAs heterostructure

2012 ◽  
Vol 1396 ◽  
Author(s):  
Tomotsugu Ishikura ◽  
Takahiro Hiraki ◽  
Takashi Matsuda ◽  
Joungeob Lee ◽  
Kanji Yoh
Keyword(s):  
Magnetic Field ◽  
Spin Polarization ◽  
Nuclear Spin ◽  
Spin Injection ◽  
Hall Voltage ◽  
Nuclear Spin Polarization ◽  
Polarized Electrons ◽  
Spin Polarized ◽  
Magnetic Metal ◽  
Out Of Plane

AbstractWe have investigated an InAs channel Hall-bar structure with ferromagnetic spin injector in one of the current terminals. After magnetizing the Fe electrode, spin polarized electrons are injected through the edge of the isolation mesa structure and the anomalous Hall voltage is observed, when electrons are injected from the ferromagnetic terminal. However, when electrons are injected from the non-magnetic metal (Ti/Au) of opposite terminal, the Hall voltage disappeared to the variation error level due to the fabrication imperfections. This result suggests the possibility that out-of-plane spin injection from the channel edge lead to perpendicular nuclear magnetic field. It is presumably caused by nuclear spin polarization in InAs channel near the spin source edge through Overhauser effect. The estimated internal magnetic field was 2000 Gauss.

scholarly journals Cluster magnetic octupole induced out-of-plane spin polarization in antiperovskite antiferromagnet

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yunfeng You ◽  
Hua Bai ◽  
Xiaoyu Feng ◽  
Xiaolong Fan ◽  
Lei Han ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Spin Polarization ◽  
Magnetic Layer ◽  
High Density ◽  
Spin Configuration ◽  
Spintronic Devices ◽  
Out Of Plane ◽  
Flow Through ◽  
New Perspective

AbstractOut-of-plane spin polarization σz has attracted increasing interests of researchers recently, due to its potential in high-density and low-power spintronic devices. Noncollinear antiferromagnet (AFM), which has unique 120° triangular spin configuration, has been discovered to possess σz. However, the physical origin of σz in noncollinear AFM is still not clear, and the external magnetic field-free switching of perpendicular magnetic layer using the corresponding σz has not been reported yet. Here, we use the cluster magnetic octupole in antiperovskite AFM Mn3SnN to demonstrate the generation of σz. σz is induced by the precession of carrier spins when currents flow through the cluster magnetic octupole, which also relies on the direction of the cluster magnetic octupole in conjunction with the applied current. With the aid of σz, current induced spin-orbit torque (SOT) switching of adjacent perpendicular ferromagnet is realized without external magnetic field. Our findings present a new perspective to the generation of out-of-plane spin polarizations via noncollinear AFM spin structure, and provide a potential path to realize ultrafast high-density applications.

SPIN ACCUMULATION IN A QUANTUM WIRE WITH THE COEXISTENCE OF RASHBA AND DRESSELHAUSE SPIN–ORBIT COUPLING

2011 ◽  
Vol 25 (26) ◽  
pp. 3495-3502 ◽  
Author(s):  
XI FU ◽  
GUANG-HUI ZHOU
Keyword(s):  
Spin Polarization ◽  
Free Electron ◽  
Quantum Wire ◽  
Scattering Matrix ◽  
Orbit Coupling ◽  
Spin Accumulation ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Matrix Approach ◽  
Out Of Plane

We investigate theoretically the spin accumulation of a quantum wire nonadiabatically connected to two normal leads in the presence of Rashba and Dresselhaus spin–orbit coupling (SOC). Using scattering matrix approach within the effective free-electron approximation, three components of spin polarization have been calculated. It is demonstrated that for the Dresselhaus SOC case the out-of-plane spin polarization does not form spin accumulation, and when the two SOC terms coexist the influence of Rashba SOC to the out-of-plane spin accumulation is dominant and symmetry of the spin accumulation is broken due to the existence of Dresselhaus SOC. Moreover, the formation of the out-of-plane spin accumulation is influenced by the ratio of Rashba and Dresselhaus strength, and when the ratio is very small the out-of-plane spin polarization does not show spin accumulation patterns. It is also shown that the spin accumulation for the system is an intrinsic one which can be distinguished from the extrinsic spin accumulation by changing the Rashba strength.

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