Magnetic excitations on 2H-NbSe2 - from adatoms and molecules to magnetically coupled nanostructures on a type II superconductor

过渡金属二硫化物2H-NbSe2是一种研究较多的ⅱ型超导体，具有二维的各向异性s波超导性。在这个项目中，我们将通过扫描隧道显微镜和光谱学（STM/STS）来探索顺磁性原子、分子和人工纳米结构与这种特殊类型超导体的局部相互作用，这提供了高能量和空间分辨率。我们将解析磁性基态和激发态，以识别与衬底的不同耦合机制和诱导多体态的空间扩展。通过一个垂直的磁场，我们将基片带入涡旋状态。这使我们能够在逐渐变化的环境中研究类似的磁性杂质，从具有高b场的涡旋核心，到磁场减少而超导性增加的区域，以及仍然存在b场的超导区域。最后，我们将研究杂质之间的短期和长期耦合机制，这强烈依赖于2H-NbSe2超导的各向异性特征，并使构建具有设计自旋性质和拓扑相的纳米结构成为可能。

The transition metal dichalcogenide 2H-NbSe2 is a well-studied type II superconductor with anisotropic s-wave superconductivity, which is two-dimensional-like. Within this project, we will explore the local interaction of paramagnetic adatoms, molecules and artificial nanostructures with this particular type of superconductor by means of scanning tunneling microscopy and spectroscopy (STM/STS), which offers high energetic and spatial resolution. We will resolve magnetic ground and excited states to identify different coupling regimes with the substrate and the spatial extend of induced many-body states. By means of a perpendicular magnetic field, we will bring the substrate into the vortex state. This allows us to study similar magnetic impurities in gradually changing environments, from the vortex core with high B-fields, to regions of decreasing fields and increasing superconductivity, and superconducting regions with still persisting B-fields. Finally, we will investigate short- and long-range coupling mechanisms between impurities, which strongly rely on the anisotropic character of the superconductivity in 2H-NbSe2, and enable the construction of nanostructures with designed spin properties and topological phases.