Modeling the interplay of non-locality and topology in correlated systems

• Applicant: Professorin Dr. Maria Roser Valenti, since 9/2024
• Subject Area: Theoretical Condensed Matter Physics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 449872909

Understanding topological properties in materials has been of major interest in the last decade with much focus being placed on non-interacting systems. For correlated materials, the developed concepts are, however, often inapplicable due to their reliance on band theory only. This project will address the interplay of correlations, topology and non-locality.We plan a microscopic modeling of strongly correlated electronic systems with a focus on building tools for the identification of their topological properties. In particular, we want to investigate the effect of non-local (k-dependent) correlations on topology. We will proceed along three lines: (i) we will explore exemplary many-body models to test and develop methods beyond a topological Hamiltonian framework to understand and describe topologically nontrivial states,(ii) we will apply these concepts to analyze the topological properties of relevant materials in QUAST, in particular WTe2 and TaX2 (X = S, Se) in various doping and multilayer arrangements in collaboration with P1, P3, P5, P6, P7, P8. For this purpose we will combine ab initio density functional theory (DFT) and projective Wannier functions with many-body techniques (TPSC+DMFT, CPT, DCA) that include momentum-dependent self-energies and correlation functions.(iii) As a complementary explorative long-term goal we will investigate possible routes for constructing topological models for interacting systems by a combination of statistical methods and machine learning techniques. This will contribute to the search, diagnosis and description in QUAST of correlated topological models and materials.

• DFG Programme: Research Units
• Subproject of: FOR 5249: Quantitative Spatio-Temporal Model-Building for Correlated Electronic Matter
• Ehemalige Antragstellerin: Dr. Maia Garcia Vergniory, until 8/2024