2D Materials – Physics of van der Waals [hetero]structures
DFG Priority program 2244
Atomistic theory of excited states in van der Waals heterostructures: Moiré confinement strain and electric field effect
Gabriel Bester, Universität Hamburg, gabriel.bester (at) uni-hamburg.de [website]
The aim of the present project is to study theoretically, using atomistic descriptions, moiré confined optical excitations in van-der-Waals heterostructures. The optical excitations we want to address include excitons, trions, biexcitons and higher charged excitons. In terms of their localization in real space we will investigate direct and indirect types of excitations. We will investigate the spin and valley degrees of freedom of excitons and exciton complexes and their sensitivity to the moiré potential (twisting angle) under external electric and strain fields to assess the full potential of the field of twistronics.
The methods used and developed are twofold. For commensurate structures, where a relatively small number of atoms can deliver a truthful description, we employ our ab-initio approach combining DFT and screened (RPA) configuration interaction. For larger moiré structures we will develop empirical pseudopotentials in combination with screened (empirical) configuration interaction.