Matching and maximum likelihood decoding of a multi-round subsystem quantum error correction experiment
Neereja Sundaresan, Theodore J. Yoder, Youngseok Kim, Muyuan Li, Edward H. Chen, Grace Harper, Ted Thorbeck, Andrew W. Cross, Antonio D. Córcoles, Maika Takita
Quantum error correction offers a promising path for performing quantum computations with low errors. Although a fully fault-tolerant execution of a quantum algorithm remains unrealized, recent experimental developments, along with improvements in control electronics, are enabling increasingly advanced demonstrations of the necessary operations for applying quantum error correction. Here, we perform quantum error correction on superconducting qubits connected in a heavy-hexagon lattice. The full processor can encode a logical qubit with distance three and perform several rounds of fault-tolerant syndrome measurements that allow the correction of any single fault in the circuitry. Furthermore, by using dynamic circuits and classical computation as part of our syndrome extraction protocols, we can exploit real-time feedback to reduce the impact of energy relaxation error in the syndrome and flag qubits. We show that the logical error varies depending on the use of a perfect matching decoder compared to a maximum likelihood decoder. We observe a logical error per syndrome measurement round as low as $\sim0.04$ for the matching decoder and as low as $\sim0.03$ for the maximum likelihood decoder. Our results suggest that more significant improvements to decoders are likely on the horizon as quantum hardware has reached a new stage of development towards fully fault-tolerant operations.
Recursive encoding and decoding of the noiseless subsystem for qudits
我们给出了一个完整的解释的无噪声子系统，保护一个单一的量子比特对集体错误和相应的递归方案所描述的C。K. Li et.等人[Phys.Rev.A84，044301（2011）]从表征理论的观点来分析。此外，我们将该构造推广到集体SU（$d$）误差影响下的量子点。我们发现，在这种递归方案下，渐近编码率是$1/d$。
A Scalable Open-Source QEC System with Sub-Microsecond Decoding-Feedback Latency
Joint Center for Quantum Information and Computer Science, University of Maryland（马里兰大学量子信息与计算科学联合中心）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
Experimental simulation of postselected closed timelike curves for decoding scrambled quantum information
National Cheng Kung University（国立成功大学）；Center for Quantum Frontiers of Research and Technology (QFort)（量子前沿研究技术中心）；RIKEN Center for Quantum Computing, RIKEN（理研量子计算中心）；Institute of Spintronics and Quantum Information, Faculty of Physics and Astronomy, Adam Mickiewicz University（亚当·密茨凯维奇大学物理与天文学学院自旋电子学与量子信息研究所）；Department of Physics, National Chung Hsing University（国立中兴大学物理系）；Physics Department, The University of Michigan（密歇根大学物理系）
Simplified circuit-level decoding using Knill error correction
Inria Paris（巴黎国家信息与自动化研究所）；Quandela（夸当德拉）；Institute for Quantum Computing, University of Waterloo（滑铁卢大学量子计算研究所）；Perimeter Institute for Theoretical Physics（理论物理前沿研究所）
Simple, Efficient, and Generic Post-Selection Decoding for qLDPC Codes
Graduate School of China Academy of Engineering Physics（中国工程物理研究院研究生院）；International Center for Elementary Particle Physics, University of Tokyo（东京大学基础粒子物理国际中心）；Department of Applied Physics, University of Tokyo（东京大学应用物理系）
Local Clustering Decoder as a fast and adaptive hardware decoder for the surface code
Riverlane；Quantum Engineering Technology Labs, H. H. Wills Physics Laboratory and Department of Electrical & Electronic Engineering, University of Bristol（布里斯托大学电气与电子工程系、H.H.威尔斯物理实验室量子工程技术实验室）
AI-Enabled Decoding of Qubit Loss for Quantum Error-Correcting Codes
Tsinghua University（清华大学）；Intelligent Quantum Inception Co., Ltd.（智量量子创新有限公司）；Institute for Advanced Study, Tsinghua University（清华大学高等研究院）；Hong Kong University of Science and Technology (Guangzhou)（香港科技大学（广州））；iFLYTEK Research（科大讯飞研究院）
Fusion-assisted decoding of non-Abelian topological order
Harvard University（哈佛大学）；Purdue University（普渡大学）；New York University（纽约大学）；State University of New York at Stony Brook（纽约州立大学石溪分校）；University of Oklahoma（俄克拉荷马大学）；NIST/University of Maryland（美国国家标准与技术研究院/马里兰大学）；University of British Columbia（不列颠哥伦比亚大学）
Logical channels in approximate Gottesman-Kitaev-Preskill error correction
Xanadu Quantum Technologies（Xanadu量子技术）；Institute of Computer and Communication Sciences, EPFL（EPFL计算机与通信科学研究所）；Centre for Quantum Computation and Communication Technology, School of Science, RMIT University（RMIT大学理学院量子计算与通信技术中心）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）
