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 |
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Article number | 117003 |
Journal | Physical Review Letters |
Volume | 101 |
Issue number | 11 |
DOIs | |
Publication status | Published - 10 Sep 2008 |
ASJC Scopus subject areas
- Physics and Astronomy(all)