Error-corrected quantum computers can only work if errors are small and uncorrelated. Here, I show how cosmic rays or stray background radiation affects superconducting qubits by modeling the phonon to electron/quasiparticle down-conversion physics. For present designs, the model predicts about 57% of the radiation energy breaks Cooper pairs into quasiparticles, which then vigorously suppress the qubit energy relaxation time (T₁ ~ 600 ns) over a large area (cm) and for a long time (ms). Such large and correlated decay kills error correction. Using this quantitative model, I show how this energy can be channeled away from the qubit so that this error mechanism can be reduced by many orders of magnitude. I also comment on how this affects other solid-state qubits.

纠错的量子计算机只有在错误很小且不相关时才能工作。在这里，我通过模拟声子到电子/准粒子下转换物理来展示宇宙射线或杂散背景辐射如何影响超导量子位。对于目前的设计，该模型预测约 57% 的辐射能量将 Cooper 对分解为准粒子，然后 在大面积 (cm) 和长时间 (ms) 上大力抑制量子位能量弛豫时间 ( T ₁ ~ 600 ns) ）。如此大且相关的衰减会扼杀纠错。使用这个定量模型，我展示了如何将这种能量从量子位引导出去，从而可以将这种错误机制减少许多数量级。我还评论了这如何影响其他固态量子位。