Electrical Low-Frequency 1/<i>f</i><sup>γ</sup> Noise Due to Surface Diffusion of Scatterers on an Ultra-low-Noise Graphene Platform.

Kamada, Masahiro; Laitinen, Antti; Zeng, Weijun; Will, Marco; Sarkar, Jayanta; Tappura, Kirsi; Seppä, Heikki; Hakonen, Pertti · Nano Lett · 2021

basic_science · Level V

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Abstract

Low-frequency 1/<i>f</i> <sup>γ</sup> noise is ubiquitous, even in high-end electronic devices. Recently, it was found that adsorbed O<sub>2</sub> molecules provide the dominant contribution to flux noise in superconducting quantum interference devices. To clarify the basic principles of such adsorbate noise, we have investigated low-frequency noise, while the mobility of surface adsorbates is varied by temperature. We measured low-frequency current noise in suspended monolayer graphene Corbino samples under the influence of adsorbed Ne atoms. Owing to the extremely small intrinsic noise of suspended graphene, we could resolve a combination of 1/<i>f</i> <sup>γ</sup> and Lorentzian noise induced by the presence of Ne. We find that the 1/<i>f</i> <sup>γ</sup> noise is caused by surface diffusion of Ne atoms and by temporary formation of few-Ne-atom clusters. Our results support the idea that clustering dynamics of defects is relevant for understanding of 1/<i>f</i> noise in metallic systems.