Probing Noise in Flux Qubits via Macroscopic Resonant Tunneling
| Autor: | 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. |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 101, 117003 (2008) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.101.117003 |
| Popis: | 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 r.m.s. amplitude of the noise, which is proportional to the decoherence rate 1/T_2^*, was observed to be weakly dependent on temperature below 70 mK. Analysis of these results indicates that the dominant source of low frequency (1/f) flux noise in this device is a quantum mechanical environment in thermal equilibrium. Comment: 4 pages 4 figures |
| Databáze: | arXiv |
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