标题： 倒装芯片量子处理器中的信号串扰 显示英文标题

标题： Signal crosstalk in a flip-chip quantum processor

摘要： 量子处理器需要具有高可寻址性（低串扰）的信号传输架构，以确保在数十个量子比特的规模上就能实现高性能。串扰会导致量子门的非预期驱动，从而对扩展设备中的量子门保真度产生不利影响。在这里，我们展示了封装的倒装芯片超导量子处理器，其信号串扰性能与在其他平台上的报告性能相当。对于电容耦合的量子比特驱动线，我们在共振时的串扰优于-27分贝（平均值为-37分贝）。对于感应耦合的磁通驱动线，我们发现直流磁通串扰小于0.13%（平均值为0.05%）。这些观察到的串扰水平足够小，并且随着距离的增加呈下降趋势，这对进一步扩展到更大的量子比特数量来说是有希望的。我们讨论了我们的结果对设计低串扰、片上信号传输架构的意义，包括屏蔽隧道结构的影响、串扰的潜在来源以及在扩展量子处理器中由串扰引起的量子门错误估计。 显示英文摘要

摘要： Quantum processors require a signal-delivery architecture with high addressability (low crosstalk) to ensure high performance already at the scale of dozens of qubits. Signal crosstalk causes inadvertent driving of quantum gates, which will adversely affect quantum-gate fidelities in scaled-up devices. Here, we demonstrate packaged flip-chip superconducting quantum processors with signal-crosstalk performance competitive with those reported in other platforms. For capacitively coupled qubit-drive lines, we find on-resonant crosstalk better than -27 dB (average -37 dB). For inductively coupled magnetic-flux-drive lines, we find less than 0.13 % direct-current flux crosstalk (average 0.05 %). These observed crosstalk levels are adequately small and indicate a decreasing trend with increasing distance, which is promising for further scaling up to larger numbers of qubits. We discuss the implication of our results for the design of a low-crosstalk, on-chip signal delivery architecture, including the influence of a shielding tunnel structure, potential sources of crosstalk, and estimation of crosstalk-induced qubit-gate error in scaled-up quantum processors.