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arXiv · 1109.5205

Thin-film superconducting resonator tunable to the ground-state hyperfine splitting of $^{87}$Rb

Z. Kim·C. P. Vlahacos·J. E. Hoffman·J. A. Grover·K. D. Voigt·B. K. Cooper·C. J. Ballard·B. S. Palmer·M. Hafezi·J. M. Taylor·J. R. Anderson·A. J. Dragt·C. J. Lobb·L. A. Orozco·S. L. Rolston·F. C. Wellstood
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Abstract

We describe a thin-film superconducting Nb microwave resonator, tunable to within 0.3 ppm of the hyperfine splitting of $^{87}$Rb at $f_{Rb}=6.834683$ GHz. We coarsely tuned the resonator using electron-beam lithography, decreasing the resonance frequency from 6.8637 GHz to 6.8278 GHz. For \emph{in situ} fine tuning at 15 mK, the resonator inductance was varied using a piezoelectric stage to move a superconducting pin above the resonator. We found a maximum frequency shift of about 8.7 kHz per 60-nm piezoelectric step and a tuning range of 18 MHz.

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Z. Kim, C. P. Vlahacos, J. E. Hoffman, J. A. Grover, K. D. Voigt, B. K. Cooper, C. J. Ballard, B. S. Palmer, M. Hafezi, J. M. Taylor, J. R. Anderson, A. J. Dragt, C. J. Lobb, L. A. Orozco, S. L. Rolston, F. C. Wellstood. 2011-09-23. Thin-film superconducting resonator tunable to the ground-state hyperfine splitting of $^{87}$Rb. https://doi.org/10.1063/1.3651466

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