Spin-torque microwave detector with out-of-plane precessing magnetic moment

2012 ◽  
Vol 111 (12) ◽  
pp. 123904 ◽  
Author(s):  
O. V. Prokopenko ◽  
I. N. Krivorotov ◽  
E. Bankowski ◽  
T. Meitzler ◽  
S. Jaroch ◽  
...  
Keyword(s):  
Magnetic Moment ◽  
Spin Torque ◽  
Out Of Plane ◽  
Microwave Detector

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

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.

Impact of Device Variability and Circuit Phase Shift in Synchronized Spin Torque Oscillators

2007 ◽  
Vol 998 ◽  
Author(s):  
Johan Persson ◽  
Yan Zhou ◽  
Johan Akerman
Keyword(s):  
Phase Diagram ◽  
Time Delay ◽  
Process Variations ◽  
Small Time ◽  
Spin Transfer Torque ◽  
Spin Torque ◽  
Plane Anisotropy ◽  
Out Of Plane ◽  
The Impact ◽  
Spin Torque Oscillators

ABSTRACTCurrent-induced magnetization dynamics in a system composed of two electrically coupled spin torque oscillators (STOs) is examined. The dynamics of the STOs is modeled by the Landau–Lifshitz–Gilbert equations modified with a Slonczewski spin-transfer torque term. To study the impact of realistic process variations on STO synchronization we let the two STOs have different in-plane anisotropy fields (Hk). The simulation also provides for a time delay τ. We construct a phase diagram of the STO synchronization as a function of Hk and direct current (Idc) at different τ. The phase diagram turns out to be quite rich with different types of synchronized precession modes. While the synchronized state is originally very sensitive to STO process variations and can only sustain up to 4% Hk variation, the addition of a small time delay dramatically improves its robustness and allows as much as 145% Hk variation in the entire out-of-plane precession regime. It is also shown that the two STOs can not only be locked in frequency, but also in phase at a given τ and the phase difference between the two STOs can be tuned by varying the dc current.

High Q factor over 3000 due to out-of-plane precession in nano-contact spin-torque oscillator based on magnetic tunnel junctions

2014 ◽  
Vol 7 (2) ◽  
pp. 023003 ◽  
Author(s):  
Hiroki Maehara ◽  
Hitoshi Kubota ◽  
Yoshishige Suzuki ◽  
Takayuki Seki ◽  
Kazumasa Nishimura ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Spin Torque ◽  
Q Factor ◽  
High Q ◽  
Out Of Plane

Intrinsic Phase Shift and Novel Dynamic Magnetization States of a Spin Torque Oscillator under ac Current Injection

2007 ◽  
Vol 998 ◽  
Author(s):  
Yan Zhou ◽  
Johan Persson ◽  
Johan Akerman
Keyword(s):  
Phase Shift ◽  
Phase Locking ◽  
Wave Length ◽  
Anisotropy Field ◽  
Spin Torque ◽  
Demagnetizing Field ◽  
Oscillation Modes ◽  
Out Of Plane ◽  
Ac Current ◽  
Dc Current

ABSTRACTWe report on a preferred phase shift ΔΦ0 between a spin torque oscillator (STO) and an ac current (Iac) injected at the intrinsic frequency (fSTO) of the STO. In the in-plane precession mode (IP) the STO adjusts to a state where its resistance (or voltage) lags Iac about a quarter of a wave length (ΔΦ0 = 87°−94°). In the IP mode ΔΦ0 increases somewhat with the dc current. As the precession changes into the Out-Of-Plane (OOP) mode, ΔΦ0 jumps by about 180°, i.e. the STO resistance now precedes Iac by about a quarter of a wave length (|ΔΦ0| = 86°). At the IP/OOP boundary, the ac current mixes the two oscillation modes and both periodic and chaotic oscillations are observed. As a consequence of mixing, subharmonic terms appear in the STO signal. ΔΦ0 can furthermore be tuned by changing one or more of the anisotropy field, the demagnetizing field or the applied field. At the IP/OOP boundary, Iac mixes the two oscillation modes. The intrinsic ΔΦ0 will impact any circuit design based on STO technology and will e.g. have direct consequences for phase locking in networks of serially connected STOs.

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

Modeling of spin-torque driven magnetization dynamics in a spin-valve with combined in-plane and out-of-plane polarizers

2011 ◽  
Vol 99 (22) ◽  
pp. 222509 ◽  
Author(s):  
Zhiwei Hou ◽  
Zongzhi Zhang ◽  
Jianwei Zhang ◽  
Yaowen Liu
Keyword(s):  
Spin Valve ◽  
Spin Torque ◽  
Magnetization Dynamics ◽  
Out Of Plane

Influence of Temperature on the Performance of a Spin-Torque Microwave Detector

2012 ◽  
Vol 48 (11) ◽  
pp. 3807-3810 ◽  
Author(s):  
Oleksandr V. Prokopenko ◽  
Elena Bankowski ◽  
Thomas Meitzler ◽  
Vasil S. Tiberkevich ◽  
Andrei N. Slavin
Keyword(s):  
Spin Torque ◽  
Influence Of Temperature ◽  
Microwave Detector ◽  
Influence Of Temperature On
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