The reduction in phase noise in electronic systems is of utmost importance in modern communication and signal processing applications and requires an understanding of the underlying physical processes. Here, we systematically study the phase noise in mutually synchronized chains of nano-constriction spin Hall nano-oscillators (SHNOs). We find that longer chains have improved phase noise figures at low offset frequencies (1/f noise), where chains of two and ten mutually synchronized SHNOs have 2.8 and 6.2 dB lower phase noise than single SHNOs. This is close to the theoretical values of 3 and 10 dB, and the deviation is ascribed to process variations between nano-constrictions. However, at higher offset frequencies (thermal noise), the phase noise unexpectedly increases with chain length, which we ascribe to process variations, a higher operating temperature in the long chains at the same drive current and phase delays in the coupling between nano-constrictions.
Phase noise analysis of mutually synchronized spin Hall nano-oscillators
Note: This paper is part of the APL Special Collection on Electronic Noise: From Advanced Materials to Quantum Technologies.
Artem Litvinenko, Akash Kumar, Mona Rajabali, Ahmad A. Awad, Roman Khymyn, Johan Åkerman; Phase noise analysis of mutually synchronized spin Hall nano-oscillators. Appl. Phys. Lett. 29 May 2023; 122 (22): 222401. https://doi.org/10.1063/5.0152381
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