First-principles study of electronic properties, topological properties and structural phase transition in the Kagome compound LaGa2Rh3

• Main Author: Dinh, Viet Hoang
• Other Authors: Chang Guoqing
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Physics; Computational material physics
• Online Access: https://hdl.handle.net/10356/175449
• Institution: Nanyang Technological University

The Kagome lattice has always been one of the most intriguing topics in Condensed Matter Physics for several decades due to its fascinating triangular nature, which is a good platform to realize several novel phenomena such as magnetic frustration, spin liquid, and quantum spin liquid. In addition, the band structure of the Kagome lattice consists of Dirac cones, Van Hove singularities and flat bands, which often result in novel transport properties such as high mobility and unconventional superconductivity. Furthermore, the presence of several crystalline symmetries in many Kagome compounds often leads to many non-trivial topological phases, which have ignited the community in recent years. Apart from the intriguing electronic, magnetic and topological properties, several Kagome compounds have also been identified to host Charge Density Wave (CDW) phases, originated from either electron-electron interaction or electron phonon interaction. The CDW phase transitions in Kagome compounds could strongly affect their crystalline symmetries and electronic band structures, thus alter numerous properties such as transport properties, magnetic properties, optical responses, and may also give rise to several correlation-driven topological phase transitions. Therefore, it is important to gain insights about the effect of CDW phase transitions on Kagome compounds in order to predict their behaviors in various conditions. In this project, LaGa2Rh3, a layer-like Kagome compound, is extensively studied using in-depth Density Functional Theory to uncover its electronic structure, topological properties and CDW phase. The effects of the CDW phase transition on its electronic band structure as well as topological properties are also analyzed. This project hopes to open a pathway to further study the correlation between CDW phases, electronic properties and topological properties of many other Kagome metals.