宽带Purcell滤波器用于超导量子比特快速复位与读取
Broadband Purcell Filter for Fast Superconducting Qubit Reset and Readout
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中文总结 AI 辅助
本文提出一种宽带Purcell滤波器，通过解耦复位与读取路径，在1.2 GHz带宽内实现超过1 ms的弛豫时间、500 ns读取和99.6%效率的100 ns复位，解决了快速操作与量子比特保护的权衡问题。
中文摘要 AI 辅助
量子比特状态的快速复位与读取对于量子纠错至关重要，然而，通过增强与耗散环境的耦合来加速这些操作，不可避免地会因Purcell效应而增加量子比特的衰减。本文提出了一种宽带Purcell滤波器，它将复位与读取路径解耦，使得两种操作可以独立优化，而无需牺牲量子比特的相干性。该滤波器利用两个工程化陷波——一个固有陷波和一个带阻陷波——来提供宽带Purcell保护，并附加一个复位短截线，在保护带下方产生一个复位模式。为了实现快速复位同时抑制滤波器介导的量子比特间相互作用，我们将每个量子比特耦合到专用的复位谐振器。我们实验证明了在1.2 GHz带宽内，Purcell限制的弛豫时间超过1 ms，同时实现了无需约瑟夫森参量放大器的500 ns读取，以及效率为99.6%的100 ns复位。复位谐振器设计时特意引入了kappa-chi失配，与读取谐振器相比，将光子散粒噪声引起的退相干抑制了70倍。我们的工作提供了一种可扩展的硬件解决方案，解决了快速量子比特操作与量子比特保护之间的传统权衡，推进了容错量子计算的前景。
英文摘要
Rapid reset and readout of qubit states are essential for quantum error correction, yet accelerating these operations through stronger coupling to a dissipative environment inevitably increases qubit decay via the Purcell effect. Here we present a broadband Purcell filter that decouples the reset and readout paths, enabling both operations to be independently optimized without compromising qubit coherence. The filter employs two engineered notches - an intrinsic notch and a bandstop notch - to provide broadband Purcell protection, together with an additional reset stub that creates a reset mode below the protected band. To enable fast reset while suppressing filter-mediated interactions between qubits, we couple each qubit to a dedicated reset resonator. We experimentally demonstrate Purcell-limited relaxation times exceeding 1 ms across a 1.2 GHz bandwidth, simultaneously with 500 ns readout without a Josephson parametric amplifier and 100 ns reset with 99.6% efficiency. The reset resonator is designed with a deliberate kappa-chi mismatch, which suppresses photon-shot-noise-induced dephasing by a factor of 70 compared to the readout resonator. Our work provides a scalable hardware solution that resolves the traditional trade-off between fast qubit operations and qubit protection, advancing the prospects for fault-tolerant quantum computing.
发表机构
- Key Laboratory of Atomic and Subatomic Structure and Quantum Control (South China Normal University), Ministry of Education, Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, School of Physics, South China Normal University（华南师范大学物理学院）
- International Quantum Academy（国际量子学院）
- School of Emerging Technology, University of Science and Technology of China（中国科学技术大学前沿技术学院）
- Southern University of Science and Technology（南方科技大学）
- Institute of Micro and Nano Optoelectronics, Shenzhen University（深圳大学微纳光电子研究院）
机构由 AI 辅助整理，请以论文原文为准。
