Novel electronic properties of atomically-engineered ultra-thin superconducting films and their emerging topological states.

Due to their impact on fundamental physics and possible applications in low-power electronics, superconducting ultra-thin films with thickness ranging from one to a few atomic layers have recently attracted tremendous interest. Their superconducting properties are strongly influenced by the thickness, geometry and structure of the film due to the quantum confinement effects on atomistic scale. Since last years, such ultra-thin films can be grown experimentally, in clean crystalline form, and tuned with atomic precision. Numerous novel electronic properties were observed and even prototype field-effect transistors were realized. However, most of the novel properties are not precisely understood from theoretical standpoint. In this project, we will therefore study the effects of atomic engineering by state-of-the-art Bogoliubov-de Gennes numerical simulations of ultrathin superconductors, with the hope to reveal the impact of atomic edge steps, disorder, and substrate choices on the superconducting condensate and its electronic structure. Emerging new topological states (including vortices, fractional vortices, and skyrmions) will be considered in the presence of magnetic field and electric current. This project will ultimately provide a comprehensive review of possible properties and how to achieve them in scanning tunneling microscope (STM) experiments on these fascinating materials.

Keywords:SUPERCONDUCTORS

Disciplines:Condensed matter physics and nanophysics