AI 中文总结
该研究提出一种可扩展边沿通Purcell滤波器，兼具高保真读出、Purcell保护与量子比特复位功能，可延长量子比特寿命，适用于大规模容错量子计算。
AI 中文摘要
具有强Purcell保护以维持量子比特相干性的高保真读出对可扩展超导量子处理器至关重要，但传统带通Purcell滤波器的有限通带和较大占用面积使其难以扩展。本文提出一种可扩展边沿通Purcell滤波器，通过单个传输边沿将读出带与受保护的量子比特带分离，使读出谐振器摆脱带宽限制。根据传输带位于截止频率之上或之下，该紧凑网络可实现为高通滤波器（HPF）或低通滤波器（LPF）。其中HPF在150纳秒脉冲下的平均读出保真度达99.46(4)%，最高可达99.56%；LPF在130纳秒脉冲下的平均读出保真度达99.49(3)%，最高可达99.57%。两种滤波器的平均单量子比特门保真度分别为99.94%（HPF）和99.93%（LPF）。与无滤波器时的Purcell极限相比，这些滤波器显著延长了量子比特寿命，且更高阶滤波器的Purcell保护效果更深。此外，滤波器的固有耗散模式提供了量子比特复位通道，形成了紧凑架构，在单个滤波器中整合了快速高保真读出、Purcell保护和有效复位功能，适用于大规模容错量子计算。
英文摘要
High-fidelity readout with strong Purcell protection of qubit coherence is essential for scalable superconducting quantum processors, yet the finite passband and sizable footprint of conventional band-pass Purcell filters make them hard to scale. Here we introduce a scalable edge-pass Purcell filter that separates the readout band from the protected qubit band by a single transmission edge, freeing the readout resonators from bandwidth constraint. Depending on whether the transmitting band lies above or below the cutoff, the compact network is realized as a high-pass filter (HPF) or a low-pass filter (LPF). The HPF reaches an average readout fidelity of 99.46(4)% (up to 99.56%) with a 150-ns pulse, and the LPF reaches 99.49(3)% (up to 99.57%) with a 130-ns pulse. The average single-qubit gate fidelities are 99.94% (HPF) and 99.93% (LPF). Relative to the filter-free Purcell limit, the filters substantially extend the qubit lifetime, and the Purcell protection deepens at higher filter order. In addition, an intrinsic dissipation mode of the filter offers a qubit-reset channel. This leads to a compact architecture that unifies fast, high-fidelity readout, Purcell protection, and effective reset within a single filter for large-scale fault-tolerant quantum computation.
Comments9 pages, 4 figures
