发表机构
IonQ Inc.; QuICS, NIST/University of Maryland; UMIACS, University of Maryland; Quantum Research Center, Technology Innovation Institute; Centre for Quantum Technologies, National University of Singapore; Nanyang Quantum Hub, School of Physical and Mathematical Sciences, Nanyang Technological University（IonQ公司; 量子信息与计算科学研究所，美国国家标准与技术研究院/马里兰大学; 统一信息管理与计算系统研究所，马里兰大学; 量子研究中心，技术创新研究所; 量子技术中心，新加坡国立大学; 南洋量子枢纽，物理与数学科学学院，南洋理工大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用综合征测量释放稳定子校验，结合泡利旋转与克利福德前馈，在稳定子码上实现确定性容错T门，并通过两个容错电路验证了机制的有效性。
AI 中文摘要
非克利福德门对于通用量子计算至关重要，然而在稳定子码中容错地实现它们仍然是一个核心挑战。在此，我们展示了综合征自由度如何介导逻辑非克利福德门。释放一个稳定子校验使得编码数据块内可用的逻辑量子比特增加一个。两次泡利旋转，随后进行综合征测量和克利福德前馈，即可在距离至少为2的每个稳定子码上，在合适的逻辑基下，实现确定性的逻辑 $T$ 门。在理想旋转期间，状态保持在一个中间稳定子码中，我们精确确定了其距离。对于具有平衡因式分解的纯码，该距离随原始码距离增长，而稳定子生成元的最大权重从上方限制了中间距离。我们在两个电路中实现了该机制，它们在局部随机电路噪声下能容忍单个故障：一个固定的22量子比特构造，允许递归错误抑制；以及一个直接的高莱码门，通过测量一个穿过非克利福德旋转的稳定子校验来保护，即使在拒绝后也能恢复未知的编码状态。串行实现采用辅助比特重用、重置和灵活的双量子比特连接，分别最多需要33和32个物理量子比特。这些结果确立了逻辑非克利福德门的通用机制，并展示了综合征测量和恢复如何保护编码信息的中间演化。
英文摘要
Non-Clifford gates are essential for universal quantum computation, yet implementing them fault-tolerantly remains a central challenge for stabilizer codes. Here, we show how a syndrome degree of freedom can mediate a logical non-Clifford gate. Releasing one stabilizer check makes an additional logical qubit available within the encoded data block. Two Pauli rotations, followed by syndrome measurement and Clifford feed-forward, then implement a deterministic logical $T$ gate on every stabilizer code of distance at least two, in a suitable logical basis. During the ideal rotations, the state remains in an intermediate stabilizer code whose distance we determine exactly. For pure codes with a balanced factorization, this distance grows with the original code distance, whereas the maximum weight of the stabilizer generators bounds the intermediate distance from above. We realize the mechanism in two circuits that tolerate a single fault under local stochastic circuit noise: a fixed 22-qubit construction admitting recursive error suppression and a direct Golay-code gate protected by measuring a stabilizer check transported through the non-Clifford rotation, which can recover the unknown encoded state even after rejection. Serial implementations with ancilla reuse, reset, and flexible two-qubit connectivity require at most 33 and 32 physical qubits, respectively. These results establish a general mechanism for logical non-Clifford gates and demonstrate how syndrome measurements and recovery can protect the intermediate evolution of encoded information.
Comments53 pages
