Dynamically suppressing cavity dephasing induced by frequency fluctuations of a coupled nonlinear mode
Abstract
High-coherence superconducting cavities offer a promising platform for quantum information, with long coherence times and negligible intrinsic dephasing. However, cavity control generally relies on nonlinear Josephson elements whose frequency fluctuations are inherited by the cavity as dephasing, potentially limiting control fidelities and eroding the noise bias used in error-correction protocols. Here, we introduce Stark-Assisted Flux-noise Evasion (SAFE), a hardware-efficient protocol that protects the cavity from inherited dephasing using only a weak off-resonant microwave drive applied to the nonlinear element. As a concrete setup, we analyze a 3D superconducting cavity dispersively coupled to a flux-tunable transmon (FTT) subject to 1/f flux noise. Analytical predictions are confirmed by Monte Carlo simulations with realistic parameters, which show that SAFE can extend the cavity dephasing time by more than an order of magnitude while keeping residual drive-induced decoherence subdominant.
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BibTeX
@misc{lu2026dynamically,
title = {{Dynamically suppressing cavity dephasing induced by frequency fluctuations of a coupled nonlinear mode}},
author = {Yunwei Lu and Xinyuan You and Ziwen Huang and Sébastien Léger and Jens Koch and Yao Lu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.04494},
eprint = {2608.04494},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.04494},
}
RIS
TY - UNPB
TI - Dynamically suppressing cavity dephasing induced by frequency fluctuations of a coupled nonlinear mode
AU - Yunwei Lu
AU - Xinyuan You
AU - Ziwen Huang
AU - Sébastien Léger
AU - Jens Koch
AU - Yao Lu
PY - 2026
DA - 2026/09/14
PB - arXiv
DO - 10.48550/arxiv.2608.04494
UR - https://arxiv.org/abs/2608.04494
AB - High-coherence superconducting cavities offer a promising platform for quantum information, with long coherence times and negligible intrinsic dephasing. However, cavity control generally relies on nonlinear Josephson elements whose frequency fluctuations are inherited by the cavity as dephasing, potentially limiting control fidelities and eroding the noise bias used in error-correction protocols. Here, we introduce Stark-Assisted Flux-noise Evasion (SAFE), a hardware-efficient protocol that protects the cavity from inherited dephasing using only a weak off-resonant microwave drive applied to the nonlinear element. As a concrete setup, we analyze a 3D superconducting cavity dispersively coupled to a flux-tunable transmon (FTT) subject to 1/f flux noise. Analytical predictions are confirmed by Monte Carlo simulations with realistic parameters, which show that SAFE can extend the cavity dephasing time by more than an order of magnitude while keeping residual drive-induced decoherence subdominant.
ER -