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Title: Spin–orbit torque controlled stochastic oscillators with synchronization and frequency tunability

Stochastic oscillators based on emerging nanodevices are attractive because of their ultra-low power requirement and the ability to exhibit stochastic resonance, a phenomenon where synchronization to weak input signals is enabled due to ambient noise. In this work, a low barrier nanomagnet-based stochastic oscillator is demonstrated, whose output jumps spontaneously between two states by harnessing the ambient thermal noise, requiring no additional power. By utilizing spin–orbit torque in a three-terminal device configuration, phase synchronization of these oscillators to weak periodic drives of particular frequencies is demonstrated. Experiments are performed to show the tunability of this synchronization frequency by controlling an electrical feedback parameter. The current required for synchronization is more than eight times smaller than that required for the deterministic switching of similar nanomagnetic devices. A model based on Kramers’ transition rate in a symmetric double well potential is adopted and dynamical simulations are performed to explain the experimental results.

 
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NSF-PAR ID:
10364140
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
American Institute of Physics
Date Published:
Journal Name:
Journal of Applied Physics
Volume:
131
Issue:
12
ISSN:
0021-8979
Page Range / eLocation ID:
Article No. 123901
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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