Ab initio description of correlated few-particle excitations

• Applicant: Dr. Thorsten Deilmann
• Subject Area: Theoretical Condensed Matter Physics
• Term: since 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 426726249

The macroscopic electronic and optical properties of nanostructured materials are determined by their quantum mechanical properties. Correlated excitations dominate the optical properties of bulk systems, quantum dots, quantum wells, and in particular of two-dimensional materials which are in the focus of current research. In these materials quasi particles like excitons or trions (i.e. excitations consisting of two or three correlated electrons and holes) offer fascinating physical properties. The reliable and predictive description of excitons and trions from first principles by the state-of-the-art GW/BSE method is feasible, but until now only in the case of vanishing doping and negligible interactions with phonons. In this project, we plan to extend these approaches to be able to describe higher doping concentrations. Adding the electron-phonon interaction allows for the calculation of the energetic positions and optical signatures of momentum-indirect transitions. Furthermore, we will apply ab initio methods to investigate the properties of novel systems like excitonic insulators.

• DFG Programme: Research Grants