Suppressing relaxation in superconducting qubits by quasiparticle pumping
Journal article, 2016
Copyright 2016 by the American Association for the Advancement of Science; all rights reserved.Dynamical error suppression techniques are commonly used to improve coherence in quantum systems.They reduce dephasing errors by applying control pulses designed to reverse erroneous coherent evolution driven by environmental noise. However, such methods cannot correct for irreversible processes such as energy relaxation.We investigate a complementary, stochastic approach to reducing errors: Instead of deterministically reversing the unwanted qubit evolution, we use control pulses to shape the noise environment dynamically. In the context of superconducting qubits, we implement a pumping sequence to reduce the number of unpaired electrons (quasiparticles) in close proximity to the device. A 70%reduction in the quasiparticle density results in a threefold enhancement in qubit relaxation times and a comparable reduction in coherence variability.
Author
S. Gustavsson
Massachusetts Institute of Technology
F. Yan
Massachusetts Institute of Technology
G. Catelani
Forschungszentrum Jülich (FZJ)
Jonas Bylander
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
A. Kamal
Massachusetts Institute of Technology
J. Birenbaum
Massachusetts Institute of Technology
D. Hover
Massachusetts Institute of Technology
D. Rosenberg
Massachusetts Institute of Technology
G. Samach
Massachusetts Institute of Technology
A.P. Sears
Massachusetts Institute of Technology
S.J. Weber
Massachusetts Institute of Technology
J.L. Yoder
Massachusetts Institute of Technology
John Clarke
UC Berkeley
A.J. Kerman
Massachusetts Institute of Technology
F. Yoshihara
RIKEN (The Institute of Physical and Chemical Research)
Y. Nakamura
University of Tokyo
Riken
T.P. Orlando
Massachusetts Institute of Technology
W.D. Oliver
Massachusetts Institute of Technology
Science
0036-8075 (ISSN)
Vol. 354 6319 1573-1577Subject Categories (SSIF 2011)
Nano Technology
Condensed Matter Physics
DOI
10.1126/science.aah5844