An Exploration of Electron-Lattice Correlations in Charge Density Wave and Superconducting Systems

The emergence of charge density wave (CDW) states, superconductivity, and surface states due to non-trivial topologies have been at the heart of condensed matter physics. Here, two classes of materials are investigated: the quasi-two dimensional (2D) transition metal dichalcogenide system 1T-TaS2−xSex and the topological Dirac metal RbBi2. 1T-TaS2−xSex offers a unique platform to investigate the interplay between CDW, superconductivity, Mott insulating behavior and quantum spin liquid state. On the other hand, the bismuth pyrochlore lattice compound RbBi2 is discovered to be a Dirac metal that becomes a type-I superconductor below 4.15 K. Despite the presence of robust spin-orbit coupling associated with a topologically nontrivial band structure, the topological characteristics of RbBi2 have never been explored before. This work focused primarily on elucidating both long- and short-range structural correlations with the charge, spin and topological orders in these systems, by employing X-ray and neutron scattering techniques coupled with thermodynamic characterization.