In recent years a plethora of new correlated states have been observed by stacking and twisting two-dimensional van der Waals materials of different kind. Some prominent examples are twisted bilayer graphene, bilayer heterostructures of graphene with the spin-orbit assisted Mott insulator α-RuCl3 -a candidate for Kitaev spin physics-, or bilayer heterostructures of the Mott insulator 1T-TaS2...
"Hund metals” are multi-orbital paramagnetic metals with sizeable effects due to the intra-atomic exchange energy or Hund’s coupling, and are characterised by strong, orbital-selective correlations and large fluctuating local magnetic moments. Their physics is relevant for iron-based superconductors and other materials like transition metal oxides.
A general feature found in models and...
One of the most widely used approaches to deal with interacting electrons is many-body perturbation theory. Although it meets its limits when it comes to strong correlation, it performs surprisingly well in other situations. In this talk we will analyze some successes and shortcomings, ranging from models of localized and of delocalized electrons to real materials. We will then advocate new...
Our perception of the natural world is significantly shaped by the properties of the detection process considered. One crucial aspect is the timescale of the probing mechanism: If this is larger than the typical timescales of the phenomenon under investigation, only averaged information will be gained.
I will illustrate the importance of this aspect for the comparison of experimental...
