Max Planck Institute of Microstructure Physics, 06108 Halle, Saxony-Anhalt, Germany.
Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
Sci Adv. 2023 Jul 14;9(28):eadg7269. doi: 10.1126/sciadv.adg7269. Epub 2023 Jul 12.
Materials with Kagome nets are of particular importance for their potential combination of strong correlation, exotic magnetism, and electronic topology. KVSb was discovered to be a layered topological metal with a Kagome net of vanadium. Here, we fabricated Josephson Junctions of KVSb and induced superconductivity over long junction lengths. Through magnetoresistance and current versus phase measurements, we observed a magnetic field sweeping direction-dependent magnetoresistance and an anisotropic interference pattern with a Fraunhofer pattern for in-plane magnetic field but a suppression of critical current for out-of-plane magnetic field. These results indicate an anisotropic internal magnetic field in KVSb that influences the superconducting coupling in the junction, possibly giving rise to spin-triplet superconductivity. In addition, the observation of long-lived fast oscillations shows evidence of spatially localized conducting channels arising from edge states. These observations pave the way for studying unconventional superconductivity and Josephson device based on Kagome metals with electron correlation and topology.
具有 Kagome 网格的材料因其强关联、奇特磁性和电子拓扑结构的潜在组合而具有特别重要的意义。KVSb 被发现是一种具有 Kagome 网格的层状拓扑金属，其中包含钒。在这里，我们制造了 KVSb 的约瑟夫森结，并在长结长度上诱导出超导性。通过磁阻和电流与相位测量，我们观察到磁场扫过方向相关的磁阻和各向异性干涉图案，对于平面内磁场具有夫琅和费图案，但对于平面外磁场则抑制了临界电流。这些结果表明 KVSb 中存在各向异性的内磁场，这会影响结中的超导耦合，可能导致自旋三重态超导性。此外，观察到长寿命的快速振荡表明存在源于边缘态的空间局域传导通道。这些观察结果为研究基于 Kagome 金属的非常规超导性和约瑟夫森器件铺平了道路，这些器件具有电子关联和拓扑结构。
