Andreev spin qubits have recently emerged as an alternative qubit platform with realizations in semiconductor–superconductor hybrid nanowires. In these qubits, the spin degree of freedom of a quasiparticle trapped in a Josephson junction is intrinsically spin–orbit coupled to the supercurrent across the junction. This interaction has previously been used to perform spin readout, but it has also been predicted to facilitate inductive multi-qubit coupling. Here we demonstrate a strong supercurrent-mediated longitudinal coupling between two distant Andreev spin qubits. We show that it is both gate- and flux-tunable into the strong coupling regime and, furthermore, that magnetic flux can be used to switch off the coupling in situ. Our results demonstrate that integrating microscopic spin states into a superconducting qubit architecture can combine the advantages of both semiconductors and superconducting circuits and pave the way to fast two-qubit gates between distant spins.

安德烈夫自旋量子位最近作为一种替代量子位平台出现，并在半导体-超导体混合纳米线中实现。在这些量子位中，约瑟夫森结中捕获的准粒子的自旋自由度本质上是与穿过结的超电流耦合的自旋轨道。这种相互作用以前曾被用来执行自旋读出，但它也被预测可以促进感应多量子位耦合。在这里，我们展示了两个遥远的安德烈夫自旋量子位之间的强超电流介导的纵向耦合。我们表明，它可以通过栅极和磁通调谐进入强耦合状态，此外，磁通量可以用于就地关闭耦合。我们的结果表明，将微观自旋态集成到超导量子位架构中可以结合半导体和超导电路的优点，并为远距离自旋之间的快速双量子位门铺平道路。