Extending coherence time beyond break-even point using only drives and dissipation

Lida Sun, Yifang Xu, Yilong Zhou, Ziyue Hua, Weiting Wang, Jie Zhou, Zi-jie Chen, Lui Zuccherelli de Paula, Qing-Xuan Jie, Guangming Xue, Haifeng Yu, Weizhou Cai, Chang-Ling Zou, Luyan Sun

公開日: 2025/9/26

Abstract

Quantum error correction (QEC) aims to mitigate the loss of quantum information to the environment, which is a critical requirement for practical quantum computing. Existing QEC implementations heavily rely on measurement-based feedback, however, constraints on readout fidelity, hardware latency, and system complexity often limit both performance and scalability. Autonomous QEC (AQEC) seeks to overcome these obstacles by stabilizing logical codewords using introduced drives that provide coherent control and engineered dissipation. Here, we propose an AQEC protocol, derived from quantum channel simulation, that is applicable to arbitrary error-correcting codes. As a demonstration, we implement the protocol using a binomial code encoded in a long-lived bosonic mode (lifetime > 1ms), and extend the logical qubit coherence time to 1.04 times that of the best physical qubit in the system. This is the first experimental realization of an AQEC-protected bosonic logical qubit beyond the break-even point, proving that coherence time can indeed be extended by introducing only drives and dissipation. Our results highlight the performance and scalability potential of AQEC, marking an important step toward large-scale, universal quantum computing.

Extending coherence time beyond break-even point using only drives and dissipation | SummarXiv | SummarXiv