AI 中文总结
研究猫量子比特逻辑操作中噪声偏差难维持问题，提出通过真空条件分束器实现保偏猫猫 CNOT 门的相干方案，仅依赖酉操作，能避免现有方案非理想性，有望在特定条件下实现兆量子比特 regime 的逻辑存储。
AI 中文摘要
猫量子比特由于其指数增强的比特翻转时间和随着光子数增加仅多项式减少的相位翻转时间，会表现出强烈的噪声偏差，使其成为硬件高效量子纠错的有吸引力候选者。然而，在猫之间的 CNOT 门等逻辑操作中难以维持这种强噪声偏差。在此，我们提出一种在两个耗散猫之间的相干 CNOT 门方案，该方案能保持指数噪声偏差。此门仅依赖酉操作，避免了许多依赖工程耗散的现有门方案的非理想性。假设组件寿命良好且非线性工程精确，该门可通过由 13 个猫量子比特组成的距离 -7 重复码在兆量子比特 regime（逻辑错误率 < 10^-6）中实现逻辑存储。
英文摘要
Cat qubits can exhibit strong noise bias due to their exponentially enhanced bit-flip times and only polynomially reduced phase-flip times with increasing photon number, which makes them attractive candidates for hardware-efficient quantum error correction. However, it is difficult to maintain this strong noise bias in logical operations such as CNOT gates between cats. Here, we propose a coherent CNOT gate scheme between two dissipative cats that preserves the exponential noise bias. The proposed gate relies only on unitary operations, which avoids the non-idealities associated with many existing gate schemes that rely on engineered dissipations. Assuming good component lifetimes and precise nonlinearity engineering, the proposed gate can enable logical memory in the megaquop regime (logical error rates < 10^-6) with a distance-7 repetition code consisting of 13 cat qubits.
