Co- and Fe- intercalated TaS₂: understanding their electronic structure combining DFT and ARPES.

Intercalated transition metal dichalcogenides has proven a very useful tool to engineer new electronic phases in two-dimensional materials.

In this talk, I will discuss the systems Co_1/3TaS₂ and Fe_1/3TaS₂. Structurally, the introduction of the 3d transition metal changes the two-dimensionality of the van der Waals TaS₂, but the electronic structure remains roughly two-dimensional. The Fermi surface lies in the Ta d states, that become doped by the presence of the 3d-cation.

Depending on the exact stoichiometry, we will show that the Fermi surfaces may change drastically. We will compare our ab initio data with ARPES experimental results to help interpret how to engineer different types of Fermi surfaces with these intercalated compounds.

Various possible spin states for the metal cations and different magnetic arrangements will be discussed and their effect on the observed band structure will be analyzed in detail.

We have also carried out phonon band structures that show that both systems are dynamically stable in their MTa₃S₆ unit cell (M being either Co or Fe). We will compare these results with diffuse scattering data and discuss the possibility of emerging charge density waves and their plausible origin.