Broadband Purcell Filter for Fast Superconducting Qubit Reset and Readout
Abstract
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.
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BibTeX
@misc{zhao2026broadband,
title = {{Broadband Purcell Filter for Fast Superconducting Qubit Reset and Readout}},
author = {Yu Zhao and Zhixu Chen and Hanxian Liu and Mingze Liu and Zixing Liu and Hao Pang and Meiyan Wan and Changkun Wu and Liuzhu Zhong and Sai Li and Yuefeng Yuan and Yuxuan Zhou and Ji Jiang and Ji Chu and Song Liu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.14081},
eprint = {2609.14081},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.14081},
}
RIS
TY - UNPB
TI - Broadband Purcell Filter for Fast Superconducting Qubit Reset and Readout
AU - Yu Zhao
AU - Zhixu Chen
AU - Hanxian Liu
AU - Mingze Liu
AU - Zixing Liu
AU - Hao Pang
AU - Meiyan Wan
AU - Changkun Wu
AU - Liuzhu Zhong
AU - Sai Li
AU - Yuefeng Yuan
AU - Yuxuan Zhou
AU - Ji Jiang
AU - Ji Chu
AU - Song Liu
PY - 2026
DA - 2026/09/12
PB - arXiv
DO - 10.48550/arxiv.2609.14081
UR - https://arxiv.org/abs/2609.14081
AB - 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.
ER -