Can radiation-induced error bursts in superconducting chips be made rare enough? · revision history

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Title

Can radiation-induced error bursts in superconducting chips be made rare enough

Plain

Superconducting quantum chips sometimes suffer sudden bursts of errors that hit many qubits together, caused by cosmic rays and natural radioactivity breaking superconducting electron pairs. Whether chip design can make such bursts rare enough that they almost never overwhelm an error-correcting code is not settled.

Precise

In transmon arrays, ionizing-radiation impacts in the substrate produce phonons that break Cooper pairs and raise the quasiparticle density near Josephson junctions, causing $T1$ drops and frequency shifts over regions of order $\mathrm{cm}^2$ for times of about 1 to 30 ms. Establish the quantitative chain (energy deposition, phonon transport, quasiparticle generation, trapping and recombination) that sets the burst rate and footprint, and determine whether gap engineering, phonon traps and shielding can lower the rate of bursts that defeat a distance-d surface-code patch to the level required for logical error rates near $10^{-12}$ per cycle.

Settled by

Measured burst rates and footprints versus shielding, junction gap profile and phonon-trap density in large arrays, reproduced by a quantitative microscopic model and fed into logical-error simulations.

Kind

phenomenon

Answer type

mechanism

References

(empty)

Literature status

partially-resolved

Status note

Gap-engineered transmon arrays (Google Quantum AI, 2024-2025, arXiv:2402.15644 and arXiv:2506.18228) strongly reduce burst-induced errors, but residual correlated phase errors from impact-induced qubit frequency shifts (up to 3 MHz, about 1 ms) remain.

Posed since

(empty)