Real-time detection of correlated quasiparticle tunneling events in a multi-qubit superconducting device

• URL: http://arxiv.org/abs/2602.01945v1
• Date: Mon, 02 Feb 2026 10:48:30 GMT
• Title: Real-time detection of correlated quasiparticle tunneling events in a multi-qubit superconducting device
• Authors: Simon Sundelin, Linus Andersson, Hampus Brunander, Simone Gasparinetti,
• Abstract summary: We simultaneously detect quasiparticle tunneling events in two co-housed, charge-sensitive transmons coupled to a common waveguide.<n>Individual events are uncorrelated across devices, whereas burst episodes occur about once per minute and are largely correlated.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Quasiparticle tunneling events are a source of decoherence and correlated errors in superconducting circuits. Understanding and ultimately mitigating these errors calls for real-time detection of quasiparticle tunneling events on individual devices. In this work, we simultaneously detect quasiparticle tunneling events in two co-housed, charge-sensitive transmons coupled to a common waveguide. We measure background quasiparticle tunneling rates at the single-hertz level, with temporal resolution of tens of microseconds. Using time-tagged coincidence analysis, we show that individual events are uncorrelated across devices, whereas burst episodes occur about once per minute and are largely correlated. These bursts have a characteristic lifetime of 7 ms and induce a thousand-fold increase in the quasiparticle tunneling rate across both devices. In addition, we identify a rarer subset of bursts which are accompanied by a shift in the offset charge, at approximately one event per hour. Our results establish a practical and extensible method to identify quasiparticle bursts in superconducting circuits, as well as their correlations and spatial structure, advancing routes to suppress correlated errors in superconducting quantum processors.

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