Interfaces in high-Tc superconductors: fundamental insights and possible applications

The transport properties of interfaces in high-Tc compounds differ systematically from those involving conventional superconductors. Over the years, the electronic properties of the interfaces have been studied in great detail by numerous groups, but a comprehensive understanding of the mechanisms controlling their properties is still in development. The universal character of the interface properties suggest that these are controlled to a large extend by universal aspects of the materials, such as microstructure, the predominant dx2−y2-symmetry of the superconducting order parameter, interface charging and bending of the electronic band structure. Understanding the material properties at these interfaces not only leads to ways controlling the interface properties, but also can be put to good use for applications.