Hysteresis regime in the operation of a dual-free-layer spin-torque nano-oscillator with out-of-plane counter-precessing magnetic moments

2013 ◽  
Vol 114 (17) ◽  
pp. 173904 ◽  
Author(s):  
O. V. Prokopenko ◽  
I. N. Krivorotov ◽  
E. N. Bankowski ◽  
T. J. Meitzler ◽  
V. S. Tiberkevich ◽  
...  
Keyword(s):  
Magnetic Moments ◽  
Spin Torque ◽  
Free Layer ◽  
Out Of Plane

scholarly journals Effective Hamiltonian for silicene under arbitrary strain from multi-orbital basis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhuo Bin Siu ◽  
Mansoor B. A. Jalil
Keyword(s):  
Tight Binding ◽  
Spin Torque ◽  
Spin Accumulation ◽  
Effective Hamiltonian ◽  
Fermi Surfaces ◽  
Orbital Basis ◽  
Lattice Symmetry ◽  
Out Of Plane ◽  
Coupling Parameters ◽  
Spin Orbit Interactions

AbstractA tight-binding (TB) Hamiltonian is derived for strained silicene from a multi-orbital basis. The derivation is based on the Slater–Koster coupling parameters between different orbitals across the silicene lattice and takes into account arbitrary distortion of the lattice under strain, as well as the first and second-order spin–orbit interactions (SOI). The breaking of the lattice symmetry reveals additional SOI terms which were previously neglected. As an exemplary application, we apply the linearized low-energy TB Hamiltonian to model the current-induced spin accumulation in strained silicene coupled to an in-plane magnetization. The interplay between symmetry-breaking and the additional SOI terms induces an out-of-plane spin accumulation. This spin accumulation remains unbalanced after summing over the Fermi surfaces of the occupied bands and the two valleys, and can thus be utilized for spin torque switching.

Precession frequency and fast switching dependence on the in-plane and out-of-plane dual spin-torque polarizers

2012 ◽  
Vol 100 (14) ◽  
pp. 142409 ◽  
Author(s):  
Hong Zhang ◽  
Zhiwei Hou ◽  
Jianwei Zhang ◽  
Zongzhi Zhang ◽  
Yaowen Liu
Keyword(s):  
Precession Frequency ◽  
Spin Torque ◽  
Fast Switching ◽  
Out Of Plane

scholarly journals Magnetization Dynamics in a Perpendicular Anisotropy Free Layer under a Spin Torque Effect with Crossed Polarization

2020 ◽  
Vol 25 (1) ◽  
pp. 54
Author(s):  
Nafeesa Rahman ◽  
Rachid Sbiaa
Keyword(s):  
Tunnel Junction ◽  
Magnetic Tunnel Junction ◽  
Film Plane ◽  
Spin Torque ◽  
Spin Angular Momentum ◽  
Perpendicular Anisotropy ◽  
Free Layer ◽  
Magnetization Dynamics ◽  
Magnetization Direction ◽  
Spin Polarized

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.

Stability Analysis of Spin-Torque Nano-oscillator in the Rotating Frame

SPIN ◽  
2019 ◽  
Vol 09 (03) ◽  
pp. 1950008
Author(s):  
HaoHsuan Chen ◽  
Lang Zeng ◽  
ChingMing Lee ◽  
Weisheng Zhao
Keyword(s):  
High Performance ◽  
Electrical Current ◽  
Nonstationary Process ◽  
Laboratory Frame ◽  
Spin Torque ◽  
Rotating Frame ◽  
Magnetization Dynamics ◽  
Applied Current ◽  
Frequency Tunability ◽  
Out Of Plane

Spin-torque nano-oscillators (STNOs) have become one of the emerging and novel microwave devices with the high performance and tunability of GHz range frequency. The nanopillar structure with an out-of-plane (OP) spin polarizer and an in-plane (IP) magnetized free layer (FL) has been considered as a good candidate for the STNOs. Using the local rotational coordinate transformation, a nonstationary process describing magnetization dynamics in the laboratory frame is therefore transformed into a stationary one in the rotating frame. In this way, the state phase diagram of this type of STNOs is well established as a function of an applied current and external field, which is also evidenced by the macrospin simulations. Also, we show that the frequency tunability of the STNOs through electrical current can be well elevated by applying a static magnetic field anti-parallel to the spin-polarizer vector.

scholarly journals Optical and magneto-optical properties of GdxFe(100-x) thin films close to the compensation point

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Eva Jesenská ◽  
Takayuki Ishibashi ◽  
Lukáš Beran ◽  
Martin Pavelka ◽  
Jaroslav Hamrle ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spectral Dependence ◽  
Room Temperature ◽  
Magnetic Moments ◽  
Perpendicular Magnetic Anisotropy ◽  
Theoretical Models ◽  
Compensation Point ◽  
Spin Torque ◽  
Dc Sputtering

Abstract Unlike ferromagnetic materials, ferrimagnetic metals have recently received considerable attention due to their bulk perpendicular magnetic anisotropy, low net magnetization and tunable magnetic properties. This makes them perfect candidates for the research of recently discovered spin-torque related phenomena. Among other ferrimagnetic metals, GdFe has an advantage in relatively large magnetic moments in both sublattices and tunability of compensation point above the room temperature by small changes in its composition. We present a systematic study of optical and magneto-optical properties of amorphous GdxFe(100-x) thin films of various compositions (x = 18.3, 20.0, 24.7, 26.7) prepared by DC sputtering on thermally oxidized SiO2 substrates. A combination of spectroscopic ellipsometry and magneto-optical spectroscopy in the photon energy range from 1.5 to 5.5 eV with advanced theoretical models allowed us to deduce the spectral dependence of complete permittivity tensors across the compensation point. Such information is important for further optical detection of spin related phenomena driven by vicinity of compensation point in nanostructures containing GdFe.

Modeling of the perpendicular polarizer-planar free layer spin torque oscillator: Micromagnetic simulations

2008 ◽  
Vol 78 (2) ◽  
Author(s):  
I. Firastrau ◽  
D. Gusakova ◽  
D. Houssameddine ◽  
U. Ebels ◽  
M.-C. Cyrille ◽  
...  
Keyword(s):  
Spin Torque ◽  
Free Layer ◽  
Micromagnetic Simulations

Observations of thermally excited ferromagnetic resonance on spin torque oscillators having a perpendicularly magnetized free layer

2014 ◽  
Vol 115 (17) ◽  
pp. 17C740 ◽  
Author(s):  
S. Tamaru ◽  
H. Kubota ◽  
K. Yakushiji ◽  
M. Konoto ◽  
T. Nozaki ◽  
...  
Keyword(s):  
Ferromagnetic Resonance ◽  
Spin Torque ◽  
Free Layer ◽  
Spin Torque Oscillators
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