Research

We employ first-principles calculations to study the electronic, spin, optical, and magnetic properties of various solids, including bulk materials, 2D monolayers, and van der Waals heterostructures. First-principles calculations are a powerful tool allowing us to study the quantum many-body problem of hundreds of atoms. With this, we are able to calculate the band structure, density of states, magnetic moments, dipole matrix elements, etc. of a material of interest. All these information are then necessary to make realistic predictions about transport phenomena, light-matter interaction, proximity coupling, etc. that can be observed in experiments. Particular examples of materials that we currently investigate are: graphene, hexagonal boron-nitride (hBN), transition-metal dichalcogenides (MoS₂, MoSe₂, WS₂, WSe₂), transiton-metal trihalides (CrI₃, CrBr₃), topological insulators (Bi₂Te₃, Sb₂Te₃), and many more.

Since the discovery of magic-angle twisted bilayer graphene, the twist angle between the individual layers of a heterostructure has been recognized as an important tuning knob in such structures. The twist angle can modify optical properties like the excitonic g-factors, influence proximity effects (e.g., spin-orbit coupling or exchange coupling) between the layers, and even introduce new phenomena like the unconventional Rashba–Edelstein effect (UREE) from radial spin textures by breaking symmetries of the untwisted structures. Moreover, just like in homobilayers, twisting heterostructures can produce Moiré patterns and their associated physical features (flat bands, enhanced correlation, formation of domains, etc.).