Energy decay and frequency shift of a superconducting qubit from non-equilibrium quasiparticles
Superconductivity
2011-07-05 v1 Mesoscale and Nanoscale Physics
Abstract
Quasiparticles are an important decoherence mechanism in superconducting qubits, and can be described with a complex admittance that is a generalization of the Mattis-Bardeen theory. By injecting non-equilibrium quasiparticles with a tunnel junction, we verify qualitatively the expected change of the decay rate and frequency in a phase qubit. With their relative change in agreement to within 4% of prediction, the theory can be reliably used to infer quasiparticle density. We describe how settling of the decay rate may allow determination of whether qubit energy relaxation is limited by non-equilibrium quasiparticles.
Keywords
Cite
@article{arxiv.1101.0862,
title = {Energy decay and frequency shift of a superconducting qubit from non-equilibrium quasiparticles},
author = {M. Lenander and H. Wang and Radoslaw C. Bialczak and Erik Lucero and Matteo Mariantoni and M. Neeley and A. D. O'Connell and D. Sank and M. Weides and J. Wenner and T. Yamamoto and Y. Yin and J. Zhao and A. N. Cleland and John M. Martinis},
journal= {arXiv preprint arXiv:1101.0862},
year = {2011}
}
Comments
Main paper: 4 pages, 3 figures, 1 table. Supplementary material: 8 pages, 3 figures