Increasing and stabilizing the coherence of superconducting quantum circuits and resonators is of utmost importance for various technologies ranging from quantum information processors to highly sensitive detectors of low-temperature radiation in astrophysics. A major source of noise in such devices is a bath of quantum two-level systems (TLSs) with broad distribution of energies, existing in disordered dielectrics and on surfaces. Here we study the dielectric loss of superconducting resonators in the presence of a periodic electric bias field, which sweeps near-resonant TLSs in and out of resonance with the resonator, resulting in a periodic pattern of Landau-Zener transitions. We show that at high sweep rates compared to the TLS relaxation rate, the coherent evolution of the TLS over multiple transitions yields a significant reduction in the dielectric loss relative to the intrinsic value. This behavior is observed both in the classical high-power regime and in the quantum single-photon regime, possibly suggesting a viable technique to dynamically decouple TLSs from a qubit.
@article{arxiv.1903.07914,
title = {Dynamical Decoupling of Quantum Two-Level Systems by Coherent Multiple Landau-Zener Transitions},
author = {Shlomi Matityahu and Hartmut Schmidt and Alexander Bilmes and Alexander Shnirman and Georg Weiss and Alexey V. Ustinov and Moshe Schechter and Jürgen Lisenfeld},
journal= {arXiv preprint arXiv:1903.07914},
year = {2021}
}