Improving materials used to make qubits is crucial to further progress in quantum information processing. Of particular interest are semiconductor-superconductor heterostructures that are expected to form the basis of topological quantum computing. We grew semiconductor indium antimonide nanowires that were coated with shells of tin of uniform thickness. No interdiffusion was observed at the interface between Sn and InSb. Tunnel junctions were prepared by in situ shadowing. Despite the lack of lattice matching between Sn and InSb, a 15-nanometer-thick shell of tin was found to induce a hard superconducting gap, with superconductivity persisting in magnetic field up to 4 teslas. A small island of Sn-InSb exhibits the two-electron charging effect. These findings suggest a less restrictive approach to fabricating superconducting and topological quantum circuits.

改进用于制作量子位的材料对于量子信息处理的进一步发展至关重要。特别令人感兴趣的是半导体-超导体异质结构，有望形成拓扑量子计算的基础。我们生长了涂有厚度均匀的锡壳的半导体铟锑化物纳米线。在Sn和InSb之间的界面上没有观察到相互扩散。隧道交界处是通过原地遮蔽来准备的。尽管在Sn和InSb之间缺乏晶格匹配，但发现15纳米厚的锡壳会引起硬的超导间隙，在磁场中，超导能持续保持到4特斯拉。Sn-InSb的小岛具有双电子充电作用。