Although qubit coherence times and gate fidelities are continuously improving, logical encoding is essential to achieve fault tolerance in quantum computing. In most encoding schemes, correcting or tracking errors throughout the computation is necessary to implement a universal gate set without adding significant delays in the processor. Here, we realize a classical control architecture for the fast extraction of errors based on multiple cycles of stabilizer measurements and subsequent correction. We demonstrate its application on a minimal bit-flip code with five transmon qubits, showing that real-time decoding and correction based on multiple stabilizers is superior in both speed and fidelity to repeated correction based on individual cycles. Furthermore, the encoded qubit can be rapidly measured, thus enabling conditional operations that rely on feed forward, such as logical gates. This co-processing of classical and quantum information will be crucial in running a logical circuit at its full speed to outpace error accumulation.

尽管量子位相干时间和门保真度不断提高，但是逻辑编码对于实现量子计算中的容错性至关重要。在大多数编码方案中，必须在整个计算过程中校正或跟踪错误，以实现通用门集而又不增加处理器的明显延迟。在这里，我们实现了一种基于稳定器测量和后续校正的多个周期来快速提取错误的经典控制架构。我们演示了它在具有五个transmon量子位的最小位翻转码上的应用，表明基于多个稳定器的实时解码和校正在速度和保真度方面均优于基于单个周期的重复校正。此外，可以快速测量编码的量子比特 因此可以启用依赖前馈的条件运算，例如逻辑门。经典和量子信息的这种协同处理对于全速运行逻辑电路以超过误差累积至关重要。