Faculty Sponsor's Department:
Topological materials, including topological insulators and Weyl and Dirac semimetals, have gained attention in the past decade due to their exceptional electronic transport and promise in quantum computing applications. Recently, topological states have also been found in material classes for energy applications (thermoelectrics, catalysts, photovoltaics). The electronic band structure of topological semimetals is characterized by linear band crossings at the Fermi energy. These crossing cause bulk electrons to behave like photons in the sense that they are essentially massless, which enhances the conductivity. Knowledge is limited about what material classes can host semimetal phases and what chemical properties – such as crystal structure, orbital hybridization and spin-orbit coupling (SOC) – promotes semimetal band structure. This work employs original Python scripts as well as density functional theory to perform a high-throughput screening for new semimetal candidates. Filtering is based on locating characteristic, linear crossings of electronic bands. Screening started from the ~52,000 band structures of inorganic, crystalline materials in the Materials Project database. About 600 high-symmetry materials passed the first filtering and the band structures of these were recalculated with SOC and filtered again. For materials that passed the second filtering, the band structure close to potential crossings was recalculated with high resolution to enable better analysis of linearity. When semimetal candidates are identified, the method can be branched out by reiterating on related materials. With this approach, we hope to find new semimetal families, gain further intuition for underlying chemical properties and provide a more complete survey of the intersection between semimetals and known energy materials.