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arXiv · 0708.2125

1/f Flux Noise in Josephson Phase Qubits

Radoslaw C. Bialczak·R. McDermott·M. Ansmann·M. Hofheinz·N. Katz·Erik Lucero·Matthew Neeley·A. D. O'Connell·H. Wang·A. N. Cleland·John M. Martinis
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Abstract

We present a new method to measure 1/f noise in Josephson quantum bits (qubits) that yields low-frequency spectra below 1Hz. Comparison of noise taken at positive and negative bias of a phase qubit shows the dominant noise source to be flux noise and not junction critical-current noise, with a magnitude similar to that measured previously in other systems. Theoretical calculations show that the level of flux noise is not compatible with the standard model of noise from two-level state defects in the surface oxides of the films.

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Radoslaw C. Bialczak, R. McDermott, M. Ansmann, M. Hofheinz, N. Katz, Erik Lucero, Matthew Neeley, A. D. O'Connell, H. Wang, A. N. Cleland, John M. Martinis. 2007-08-16. 1/f Flux Noise in Josephson Phase Qubits. https://doi.org/10.1103/physrevlett.99.187006

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