← Back to search

Excitation of Superconducting Qubits from Hot Nonequilibrium Quasiparticles

J. Wenner, Yi Yin, Erik Lucero, R. Barends, Yu Chen, B. Chiaro, J. Kelly, M. Lenander, Matteo Mariantoni, A. Megrant, C. Neill, P. J. J. O’Malley, D. Sank, A. Vainsencher, H. Wang, T. C. White, A. N. Cleland, John M. Martinis

DOI 10.1103/PhysRevLett.110.150502 · Physical Review Letters

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

Superconducting qubits probe environmental defects such as nonequilibrium quasiparticles, an important source of decoherence. We show that “hot” nonequilibrium 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-negligible increase in the qubit excited state probability Pe. By injecting hot quasiparticles into a qubit, we experimentally measure an increase of Pe in semiquantitative agreement with the model and rule out the typically assumed thermal distribution.

Similar papers