Probing noise in flux qubits via macroscopic resonant tunneling

R. Harris, M. W. Johnson, S. Han, A. J. Berkley, J. Johansson, P. Bunyk, E. Ladizinsky, S. Govorkov, M. C. Thom, S. Uchaikin, B. Bumble, A. Fung, A. Kaul, A. Kleinsasser, M. H S Amin, D. V. Averin

Division for Electronic Engineering

Research output: Contribution to journal › Article

49 Citations (Scopus)

Abstract

Macroscopic resonant tunneling between the two lowest lying states of a bistable rf SQUID is used to characterize noise in a flux qubit. Measurements of the incoherent decay rate as a function of flux bias revealed a Gaussian-shaped profile that is not peaked at the resonance point but is shifted to a bias at which the initial well is higher than the target well. The rms amplitude of the noise, which is proportional to the dephasing rate 1/τφ, was observed to be weakly dependent on temperature below 70mK. Analysis of these results indicates that the dominant source of low energy flux noise in this device is a quantum mechanical environment in thermal equilibrium.

Original language	English
Article number	117003
Journal	Physical Review Letters
Volume	101
Issue number	11
DOIs	https://doi.org/10.1103/PhysRevLett.101.117003
Publication status	Published - 10 Sep 2008

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ASJC Scopus subject areas

Physics and Astronomy(all)

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Harris, R., Johnson, M. W., Han, S., Berkley, A. J., Johansson, J., Bunyk, P., ... Averin, D. V. (2008). Probing noise in flux qubits via macroscopic resonant tunneling. Physical Review Letters, 101(11), [117003]. https://doi.org/10.1103/PhysRevLett.101.117003

Probing noise in flux qubits via macroscopic resonant tunneling. / Harris, R.; Johnson, M. W.; Han, S.; Berkley, A. J.; Johansson, J.; Bunyk, P.; Ladizinsky, E.; Govorkov, S.; Thom, M. C.; Uchaikin, S.; Bumble, B.; Fung, A.; Kaul, A.; Kleinsasser, A.; Amin, M. H S; Averin, D. V.

In: Physical Review Letters, Vol. 101, No. 11, 117003, 10.09.2008.

Research output: Contribution to journal › Article

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AU - Uchaikin, S.

AU - Bumble, B.

AU - Fung, A.

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10.1103/PhysRevLett.101.117003