近日，加拿大D-Wave Quantum公司团队报道了双轨擦除量子比特的纠缠门。2026年8月5日出版的《自然》杂志发表了这项成果。

量子纠错（QEC）很可能将是充分发挥量子计算潜力的必要条件，但其伴随的硬件开销令人生畏，且对物理量子比特的门错误率要求极低。这些要求可以通过设计具有强错误层级的量子比特来缓解，即最常见的噪声信道同时也是最容易纠正的信道。当可检测的泄漏到计算子空间外的错误主导残余的泡利错误时，擦除量子比特就能实现这一点，从而获得更高的阈值以及随码距扩展而改善的性能。实际上，这些优势只有在所有门操作和运算过程中尽可能保持错误层级的情况下才能实现。

研究组设计并实现了一种用于双轨腔量子比特的两量子比特纠缠门，这类量子比特是一种编码在超导微波腔对中的擦除量子比特。实验证实，在该门操作过程中错误层级基本得以保持。该门速度较快（持续时间约500纳秒），每次门的擦除率低至约0.5%，残余泡利错误低于0.1%，且强烈偏向于退相位错误，其中比特翻转错误实际上在10^-6量级上几乎不存在。这些结果为更快地实现纠错系统开辟了道路——这类系统在扩展时能迅速抑制错误；研究组通过详细的表面码模拟为这一论断提供了支持。

附：英文原文

Title: An entangling gate for dual-rail erasure qubits

Author: Nitish Mehta, Kevin S. Chou or Robert J. Schoelkopf.

Issue&Volume: 2026-08-05

Abstract: Quantum error correction (QEC) will likely be required to realize the full potential of quantum computing, but comes with daunting hardware overheads and demands low gate errors on the physical qubits1,2,3,4. These requirements can be eased by engineering qubits with a strong error hierarchy, in which the most common noise channels are also the easiest to correct. Erasure qubits can achieve this when detectable leakage errors out of the computational subspace dominate over the residual Pauli errors5,6,7,8,9,10,11, resulting in higher thresholds and improved scaling with code distance5,12,13. In practice, these advantages come to fruition only if the error hierarchy is preserved as much as possible throughout all gates and operations. Here we design and realize a two-qubit entangling gate for dual-rail cavity qubits, a type of erasure qubit encoded in a pair of superconducting microwave cavities7. Our experimental demonstration confirms that the error hierarchy is largely preserved during the gate. The gate is fast (about 500ns duration) and shows low erasure rates of approximately 0.5% per gate, remaining Pauli errors below 0.1%, and a strong bias towards dephasing errors, in which bit-flips are practically non-existent at the 106 level. These results enable a faster path to error-corrected systems that rapidly suppress errors as they scale; a claim we support with our detailed surface code simulations.

DOI: 10.1038/s41586-026-10822-y

Source: https://www.nature.com/articles/s41586-026-10822-y