Würzburg ToCoTronics Colloquium

About two decades ago, initial observations of the unconventional electronic properties of graphene sparked interest in two-dimensional materials. Since then, many different 2D materials have been investigated, revealing their only their potential applications but alsointeresting physics, which includes a variety of phenomena such as ballistic transport, superconductivity, charge density waves, and topological states. It is obvious that the properties of a two-dimensional material are strongly influenced by its environment.

We use epitaxial graphene grown on SiC(0001) as a platform because it can be grown on a large scale and provides us with high-quality material with reproducible properties. My presentation will begin with a brief summary of the most important properties of epitaxial graphene. Next, I will show how intercalation, i.e., the insertion of foreign substances between graphene and SiC, can be used to modify the properties of graphene. Here, I will focus mainly on hydrogen. I will then discuss two examples in which the properties of the intercalated material are the main focus. The first case is intercalated Bi, which exhibits different structures with characteristic electronic properties. The second case is intercalated Si, which exhibits dangling bond states that undergo a Mott-Hubbard transition.