Frequency modulation of spin torque oscillator pairs

@article{Pogoryelov2011FrequencyMO,
  title={Frequency modulation of spin torque oscillator pairs},
  author={Ye. Pogoryelov and Pranaba Kishor Muduli and Stefano Bonetti and Ezio Iacocca and Frederick B. Mancoff and J Aakerman},
  journal={Applied Physics Letters},
  year={2011},
  volume={98},
  pages={192501}
}
The current controlled modulation of nanocontact based spin torque oscillator (STO) pairs is studied in both the synchronized and nonsynchronized states. The synchronized state shows a well behaved modulation and demonstrates robust mutual locking even under strong modulation. The power distribution of the modulation sidebands can be quantitatively described by assuming a single oscillator model. However, in the nonsynchronized state, the modulation sidebands are not well described by the model… 

Figures from this paper

Modulation of Individual and Mutually Synchronized Nanocontact-Based Spin Torque Oscillators
We study current modulation of spin torque oscillators (STOs) based on single and double nano-contacts. For single nano-contact devices, we show modulation for a carrier frequency of 19-40 GHz and
Modulation-mediated unlocking of a parametrically phase-locked spin torque oscillator
Modulation of an oscillator is crucial for its application in communication devices. While the output power and linewidth of single magnetic tunnel junction-based spin-torque oscillators (MTJ-STO)
Spin Torque Oscillators and RF Currents—Modulation, Locking, and Ringing
We study the interaction between a nano-contact spin torque oscillator (STO) and injected radio-frequency and microwave currents. Modulation of the STO signal is observed over a wide frequency range
Spin-torque oscillator linewidth narrowing under current modulation
We study the behavior of the linewidth of a nanocontact based spin torque oscillator (STO) under application of a radio frequency (100 MHz) modulating current. We achieve a significant (up to 85%)
Intrinsic frequency doubling in a magnetic tunnel junction–based spin torque oscillator
We show that the frequency of a magnetic tunnel junction (MTJ)-based spin torque oscillator (STO) can be doubled and the first harmonic entirely suppressed by orienting the free and fixed layer
Parametric excitation in a magnetic tunnel junction-based spin torque oscillator
Using microwave current injection at room temperature, we demonstrate parametric excitation of a magnetic tunnel junction (MTJ)-based spin-torque oscillator (STO). Parametric excitation is observed
Generation of multipeak spectrum of spin torque oscillator in non-linear regime
We investigate the spectral characteristics of spin torque oscillator (STO) excited by the spin Hall-induced spin current. We observe that the modest spin current injection triggers the conventional
A high-speed single sideband generator using a magnetic tunnel junction spin torque nano-oscillator
TLDR
A novel single sideband (SSB) modulation phenomenon is demonstrated using a magnetic tunnel junction (MTJ)-based STNO, which saves transmission bandwidth and in principle should minimize attenuation for wireless communication.
Time Required to Injection-Lock Spin Torque Nanoscale Oscillators
We have injection-locked a spin-transfer oscillator to a second-harmonic electrical input signal and measured the relative phase and amplitude of the device output as a function of DC current under
Mutually synchronized bottom-up multi-nanocontact spin-torque oscillators.
TLDR
This work presents an alternative, simple and cost-effective bottom-up method to realize large ensembles of synchronized nanocontact spin-torque oscillators and demonstrates mutual synchronization of three high-frequencynanocontacts spin-Torque oscillator and pairwise synchronization in devices with four and five nanOContacts.
...
...

References

SHOWING 1-10 OF 34 REFERENCES
Nonlinear frequency and amplitude modulation of a nanocontact-based spin-torque oscillator
We study the current-controlled modulation of a nanocontact spin-torque oscillator. Three principally different cases of frequency nonlinearity (d(2)f/dI(dc)(2) being zero, positive, and negative) ...
Frequency modulation of spin-transfer oscillators
Spin-polarized dc electric current flowing into a magnetic layer can induce precession of the magnetization at a frequency that depends on current. We show that addition of an ac current to this dc
Phase locking of spin-torque oscillators by spin-wave interactions
The spin-wave mediated interaction leading to the phase locking of two spin-torque oscillators is studied. The effective coupling parameter is derived and unexpectedly found to exhibit an oscillatory
Phase-locking and frustration in an array of nonlinear spin-torque nano-oscillators
We demonstrate that the cooperative dynamics of an array of coupled spin-torque nano-oscillators (STNO) can be controlled by introduction of an additional external phase shift βc between microwave
Mode locking of spin waves excited by direct currents in microwave nano-oscillators.
A spin-wave theory is presented which explains the frequency pulling and mode locking observed when two closely spaced spin-transfer nanometer-scale oscillators with slightly different frequencies
Theory of mutual phase locking of spin-torque nanosized oscillators
A theory of mutual phase locking of a pair of generating magnetic nanocontacts driven by a spin-polarized current is developed using the general theory of coupled nonlinear oscillators. Expressions
Mutual phase-locking of microwave spin torque nano-oscillators
TLDR
It is shown that two STNOs in close proximity mutually phase-lock—that is, they synchronize, which is a general tendency of interacting nonlinear oscillator systems.
Capacitance Enhanced Synchronization of Pairs of Spin-Transfer Oscillators
Macro-spin simulations have been performed to study the synchronization of pairs of serially connected spin torque oscillators in parallel with a capacitor. The sensitivity to the STO process
Perpendicular spin torque promotes synchronization of magnetic tunnel junction based spin torque oscillators
We study how the perpendicular spin transfer torque term (bj), present in magnetic tunneling junctions (MTJs), affects the synchronization of serially connected MTJ-based spin torque oscillators
Synchronization of spin-transfer oscillators driven by stimulated microwave currents
This article presents numerical simulations to study the synchronization of electrically connected STOs (spin transfer oscillators). The motion of the magnetizations mj of the layers F2 of a
...
...