Atomistic theory of excited states in van-der-Waals heterostructures: Moiré confinement, strain and electric field effects.

• Applicant: Professor Dr. Gabriel Bester
• Subject Area: Theoretical Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Theoretical Chemistry: Molecules, Materials, Surfaces
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 443406340

The aim of the present project is to study excited states in van-der-Waals heterostructures including Moiré confinement effects in the presence of strain and electric fields. The calculated excited states include excitons, trions, biexcitons and higher charged excitons. The underlying theory is atomistic and involves the calculations of up to 3,000 atoms at the first-principles DFT level and up to 50,000 atoms at the semi-empirical (AEP) level (AEPs were developed in the first funding period). The structural relaxation, including reconstructions, is obtained using our classical force field (developed in the first funding period). The single-particle results are subsequently used in our screened CI methodology to finally obtain the many-body excitations mentioned (excitons, trions and biexcitons). A significant part of the work is performed in collaborations with SPP priority program groups specified in one dedicated work package.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2244: 2D Materials – Physics of van der Waals [hetero]structures (2DMP)
• Co-Investigators: Dr. Sumanti Patra; Dr. Torben Steenbock