Improving the Time Stability of Superconducting Planar Resonators
Abstract
Quantum computers are close to become a practical technology. Solidstate implementations based, for example, on superconducting devices strongly rely on the quality of the constituent materials. In this work, we fabricate and characterize superconducting planar resonators in the microwave range, made from aluminum films on silicon substrates. We study two samples, one of which is unprocessed and the other cleaned with a hydrofluoric acid bath and by heating at $880^{\circ}$C in high vacuum. We verify the efficacy of the cleaning treatment by means of scanning transmission electron microscope imaging of samples' cross sections. From 3 hlong resonator measurements at $\approx 10$ mK and with $\approx 10$ photonic excitations, we estimate the frequency flicker noise level using the Allan deviation and find an approximately tenfold noise reduction between the two samples; the cleaned sample shows a flicker noise power coefficient for the fractional frequency of $\approx 0.23 \times 10^{15}$. Our preliminary results follow the generalized tunneling model for twolevel state defects in amorphous dielectric materials and show that suitable cleaning treatments can help the operation of superconducting quantum computers.
 Publication:

arXiv eprints
 Pub Date:
 April 2019
 arXiv:
 arXiv:1905.00131
 Bibcode:
 2019arXiv190500131M
 Keywords:

 Physics  Applied Physics;
 Quantum Physics
 EPrint:
 13 pages, 5 figures, 2 tables