Strongly quadrature-dependent noise in superconducting micro-resonators measured at the vacuum-noise limit

J. Gao; L. R. Vale; J. A. B. Mates; D. R. Schmidt; G. C. Hilton; K. D. Irwin; F. Mallet; M. A. Castellanos-Beltran; K. W. Lehnert; J. Zmuidzinas; H. G. Leduc

doi:10.1063/1.3597156

arXiv · 1008.0046

Strongly quadrature-dependent noise in superconducting micro-resonators measured at the vacuum-noise limit

J. Gao·L. R. Vale·J. A. B. Mates·D. R. Schmidt·G. C. Hilton·K. D. Irwin·F. Mallet·M. A. Castellanos-Beltran·K. W. Lehnert·J. Zmuidzinas·H. G. Leduc

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Abstract

We measure frequency- and dissipation-quadrature noise in superconducting lithographed microwave resonators with sensitivity near the vacuum noise level using a Josephson parametric amplifier. At an excitation power of 100~nW, these resonators show significant frequency noise caused by two-level systems. No excess dissipation-quadrature noise (above the vacuum noise) is observed to our measurement sensitivity. These measurements demonstrate that the excess dissipation-quadrature noise is negligible compared to vacuum fluctuations, at typical readout powers used in micro-resonator applications. Our results have important implications for resonant readout of various devices such as detectors, qubits and nano-mechanical oscillators.

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J. Gao, L. R. Vale, J. A. B. Mates, D. R. Schmidt, G. C. Hilton, K. D. Irwin, F. Mallet, M. A. Castellanos-Beltran, K. W. Lehnert, J. Zmuidzinas, H. G. Leduc. 2010-07-31. Strongly quadrature-dependent noise in superconducting micro-resonators measured at the vacuum-noise limit. https://doi.org/10.1063/1.3597156

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