A semi-empirical model for two-level system noise in superconducting microresonators

Jiansong Gao; Miguel Daal; John M. Martinis; Benjamin A. Mazin; Peter K. Day; Henry G. Leduc; Anastasios Vayonakis; Bernard Sadoulet; Jonas Zmuidzinas

doi:10.1063/1.2937855

arXiv · 0804.0467

A semi-empirical model for two-level system noise in superconducting microresonators

Jiansong Gao·Miguel Daal·John M. Martinis·Benjamin A. Mazin·Peter K. Day·Henry G. Leduc·Anastasios Vayonakis·Bernard Sadoulet·Jonas Zmuidzinas

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Abstract

We present measurements of the low--temperature excess frequency noise of four niobium superconducting coplanar waveguide microresonators, with center strip widths $s_r$ ranging from 3 $μ$m to 20 $μ$m. For a fixed internal power, we find that the frequency noise decreases rapidly with increasing center strip width, scaling as $1/s_r^{1.6}$. We show that this geometrical scaling is readily explained by a simple semi-empirical model which assumes a surface distribution of independent two-level system fluctuators. These results allow the resonator geometry to be optimized for minimum noise.

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Jiansong Gao, Miguel Daal, John M. Martinis, Benjamin A. Mazin, Peter K. Day, Henry G. Leduc, Anastasios Vayonakis, Bernard Sadoulet, Jonas Zmuidzinas. 2008-04-03. A semi-empirical model for two-level system noise in superconducting microresonators. https://doi.org/10.1063/1.2937855

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