Correlated Quasiparticle Poisoning from Phonon-Only Events in Superconducting Qubits
Phys. Rev. Lett. 135, 123601 – Published 15 September, 2025
DOI: https://doi.org/10.1103/h65v-ttbw
Abstract
Errors that are correlated across a qubit array pose an obstacle to quantum error correction. We observe elevated correlated poisoning rates in superconducting qubit arrays at the start of a cooldown followed by power-law reductions in time, while the rate of offset charge shifts remains constant, evidence of nonionizing sources of pair-breaking phonon bursts. We also investigate different sample packages, with some exhibiting elevated poisoning due to mechanical impacts from the cryocooler. Possible sources include relaxation of built-up stress in device thin films, substrates, or packaging.