标题： 在锗中的弹道超电流离散化和微米长约瑟夫森耦合 显示英文标题

标题： Ballistic supercurrent discretization and micrometer-long Josephson coupling in germanium

摘要： 我们在锗量子阱中制造约瑟夫森场效应晶体管，通过超导铝接触，并展示了由空穴携带的超电流，其范围扩展到几微米的结长度。 在超导量子点接触中，我们观察到超电流的离散化以及法布里-珀罗共振，证明了弹道输运。 超电流的磁场依赖性呈现出清晰的弗劳恩霍夫类似模式，而在微波照射下出现莎伊夏步骤。 多重安德列夫反射导致电导增强，并表明界面具有透射性，通过分析过量电流得以确认。 这些弹道超导输运的演示为锗中的混合量子技术提供了前景。 显示英文摘要

摘要： We fabricate Josephson field-effect-transistors in germanium quantum wells contacted by superconducting aluminum and demonstrate supercurrents carried by holes that extend over junction lengths of several micrometers. In superconducting quantum point contacts we observe discretization of supercurrent, as well as Fabry-Perot resonances, demonstrating ballistic transport. The magnetic field dependence of the supercurrent follows a clear Fraunhofer-like pattern and Shapiro steps appear upon microwave irradiation. Multiple Andreev reflections give rise to conductance enhancement and evidence a transparent interface, confirmed by analyzing the excess current. These demonstrations of ballistic superconducting transport are promising for hybrid quantum technology in germanium.