Anthony-Petersen Robin, Biekert Andreas, Bunker Raymond, Chang Clarence L, Chang Yen-Yung, Chaplinsky Luke, Fascione Eleanor, Fink Caleb W, Garcia-Sciveres Maurice, Germond Richard, Guo Wei, Hertel Scott A, Hong Ziqing, Kurinsky Noah, Li Xinran, Lin Junsong, Lisovenko Marharyta, Mahapatra Rupak, Mayer Adam, McKinsey Daniel N, Mehrotra Siddhant, Mirabolfathi Nader, Neblosky Brian, Page William A, Patel Pratyush K, Penning Bjoern, Pinckney H Douglas, Platt Mark, Pyle Matt, Reed Maggie, Romani Roger K, Santana Queiroz Hadley, Sadoulet Bernard, Serfass Bruno, Smith Ryan, Sorensen Peter, Suerfu Burkhant, Suzuki Aritoki, Underwood Ryan, Velan Vetri, Wang Gensheng, Wang Yue, Watkins Samuel L, Williams Michael R, Yefremenko Volodymyr, Zhang Jianjie
Physics, University of California, Berkeley, Berkeley, 94703, CA, USA.
Physics, Lawrence Berkeley National Laboratory, Berkeley, 94703, CA, USA.
Nat Commun. 2024 Jul 31;15(1):6444. doi: 10.1038/s41467-024-50173-8.
The performance of superconducting qubits is degraded by a poorly characterized set of energy sources breaking the Cooper pairs responsible for superconductivity, creating a condition often called "quasiparticle poisoning". Both superconducting qubits and low threshold dark matter calorimeters have observed excess bursts of quasiparticles or phonons that decrease in rate with time. Here, we show that a silicon crystal glued to its holder exhibits a rate of low-energy phonon events that is more than two orders of magnitude larger than in a functionally identical crystal suspended from its holder in a low-stress state. The excess phonon event rate in the glued crystal decreases with time since cooldown, consistent with a source of phonon bursts which contributes to quasiparticle poisoning in quantum circuits and the low-energy events observed in cryogenic calorimeters. We argue that relaxation of thermally induced stress between the glue and crystal is the source of these events.
超导量子比特的性能会因一组特性不明的能量源而退化，这些能量源会破坏负责超导性的库珀对，从而产生一种常被称为“准粒子中毒”的情况。超导量子比特和低阈值暗物质量热计都观测到了准粒子或声子的过量爆发，且其发生率会随时间降低。在此，我们表明，一块粘在其支架上的硅晶体所展现出的低能声子事件发生率，比一块以低应力状态从其支架上悬挂的功能相同的晶体高出两个多数量级。自冷却以来，粘合晶体中的过量声子事件发生率随时间降低，这与一种声子爆发源相符，该爆发源会导致量子电路中的准粒子中毒以及低温量热计中观测到的低能事件。我们认为，胶水和晶体之间热致应力的松弛是这些事件的根源。
