Excitation of superconducting qubits from hot non-equilibrium quasiparticles
Abstract
Superconducting qubits probe environmental defects such as non-equilibrium quasiparticles, an important source of decoherence. We show that "hot" non-equilibrium quasiparticles, with energies above the superconducting gap, affect qubits differently from quasiparticles at the gap, implying qubits can probe the dynamic quasiparticle energy distribution. For hot quasiparticles, we predict a non-neligable increase in the qubit excited state probability P_e. By injecting hot quasiparticles into a qubit, we experimentally measure an increase of P_e in semi-quantitative agreement with the model and rule out the typically assumed thermal distribution.
Keywords
Cite
@article{arxiv.1209.1674,
title = {Excitation of superconducting qubits from hot non-equilibrium quasiparticles},
author = {J. Wenner and Yi Yin and Erik Lucero and R. Barends and Yu Chen and B. Chiaro and J. Kelly and M. Lenander and Matteo Mariantoni and A. Megrant and C. Neill and P. J. J. O'Malley and D. Sank and A. Vainsencher and H. Wang and T. C. White and A. N. Cleland and John M. Martinis},
journal= {arXiv preprint arXiv:1209.1674},
year = {2013}
}
Comments
Main paper: 5 pages, 5 figures. Supplement: 1 page, 1 figure, 1 table. Updated to user-prepared accepted version. Key changes: Supplement added, Introduction rewritten, Figs.2,3,5 revised, Fig.4 added