DFT+DMFT Investigation of Strongly Correlated Topological Materials

• Applicant: Professor Hongbin Zhang, Ph.D.
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314924804

Strongly correlated topological phases combine the emergent phenomena of spontaneous symmetry breaking driven by electron-electron interaction with the nontrivial topology of the quantum wave functions. Materials which host such phases are promising candidates for a wide spectrum of applications. However, a characterization of their topological nature based on accurate correlated electronic structure obtained using methods beyond density functional theory (DFT) with proper treatment of correlations is still missing for real materials. Such a consistent way to obtain the topological character of correlated materials is valuable to understand the current experimental observations and will guide further design of novel materials. The purpose of this project is to implement effective theoretical methods which can be applied to characterize correlated topological materials based on DFT and dynamical mean field theory (DMFT) methods, focusing on systems where local electronic correlations are important. We aim at extending and applying the current DFT+DMFT methodology for a consistent treatment of spin-orbit coupling and local electronic correlations to obtain accurate electronic structure, and then to evaluate various topological invariants following the simplified interacting topological theory. While a particular focus falls on the topological characterization of correlated insulating materials, as well as explicit exploration of the surface states therein by performing calculations in the slab geometry, we also dedicate special attention to semimetallic systems with nontrivial topological nature together with quantitative evaluation of benchmarking transport properties.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1666: Topological Insulators: Materials - Fundamental Properties - Devices
• Co-Investigator: Jürgen Weischenberg