2011/01/05 by M. Lenander, H. Wang, Radoslaw C. Bialczak +18
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.84.024501
published as Phys. Rev. B 84, 024501 (2011) · Main paper: 4 pages, 3 figures, 1 table. Supplementary material: 8 pages, 3 figures
arxiv created 2011/01/05 · openalex publication_date 2011/07/01 · arxiv updated 2011/07/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
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 nonequilibrium quasiparticles with a tunnel junction, we verify qualitatively the expected change of the decay rate and transition 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 nonequilibrium quasiparticles.