Feedback control of qubits is a highly demanded technique for advanced quantum information protocols such as fault-tolerant quantum error correction. Here we demonstrate active reset of a silicon spin qubit using feedback control. The active reset is based on quantum non-demolition (QND) readout of the qubit and feedback according to the readout results, which is enabled by hardware data processing and sequencing. We incorporate a cumulative readout technique to the active reset protocol, enhancing initialization fidelity above a limitation imposed by the single-shot QND readout fidelity. An analysis of the reset protocol implies a pathway to achieve the initialization fidelity sufficient for fault-tolerant quantum computation. These results provide a practical approach to high-fidelity qubit operations in realistic devices.

量子比特的反馈控制是高级量子信息协议（如容错量子纠错）的一项非常需要的技术。在这里，我们演示了使用反馈控制对硅自旋量子位进行主动重置。主动复位基于量子位的量子非破坏（QND）读出并根据读出结果反馈，这是通过硬件数据处理和排​​序实现的。我们将累积读出技术结合到主动重置协议中，将初始化保真度提高到单次 QND 读出保真度所施加的限制之上。对重置协议的分析暗示了实现足以容错量子计算的初始化保真度的途径。这些结果为现实设备中的高保真量子比特操作提供了一种实用方法。