Two promising architectures for solid-state quantum information processing are based on electron spins electrostatically confined in semiconductor quantum dots and the collective electrodynamic modes of superconducting circuits. Superconducting electrodynamic qubits involve macroscopic numbers of electrons and offer the advantage of larger coupling, whereas semiconductor spin qubits involve individual electrons trapped in microscopic volumes but are more difficult to link. We combined beneficial aspects of both platforms in the Andreev spin qubit: the spin degree of freedom of an electronic quasiparticle trapped in the supercurrent-carrying Andreev levels of a Josephson semiconductor nanowire. We performed coherent spin manipulation by combining single-shot circuit–quantum-electrodynamics readout and spin-flipping Raman transitions and found a spin-flip time T_S = 17 microseconds and a spin coherence time T_2E = 52 nanoseconds. These results herald a regime of supercurrent-mediated coherent spin-photon coupling at the single-quantum level.

固态量子信息处理的两种有前途的架构基于静电限制在半导体量子点中的电子自旋和超导电路的集体电动模式。超导电动量子位涉及宏观数量的电子并提供更大耦合的优势，而半导体自旋量子位涉及被困在微观体积中的单个电子，但更难以链接。我们在安德列夫自旋量子位中结合了两个平台的优点：被困在约瑟夫森半导体纳米线的携带超电流的安德列夫能级中的电子准粒子的自旋自由度。T _S = 17 微秒，自旋相干时间T _2E = 52 纳秒。这些结果预示着单量子水平上超电流介导的相干自旋光子耦合机制。