Chemical tuning effects on the extreme magnetoresistance of Dirac node arcs semimetal PtSn₄

PtSn₄ is a novel topological semimetal and hosts Dirac arcs in its momentum space such that the conduction and valence band touch in loops and not at a point or line. One of the dominating electronic properties for this material is its ultrahigh magnetoresistance (XMR) at low temperature, which onsets at 30K. This XMR has been linked to the unique energy dispersion and gapless band crossings, which impart topological character to the PtSn₄ structure. Hence, the XMR can be seen as inextricably linked to the topology, as in WTe₂, NbP, and others. In this talk, I will address the chemical and electronic properties related to the topology of the band structure of PtSn₄ and explain what happens to these properties when we try and perturb the system via chemical substitutions. We replace some of the Pt in the PtSn₄ with Au/Ir and characterize the structural modifications and the effects on the XMR. Understanding this interplay between the electronic, chemical, and topological properties can provide us with the much-needed playground to find and investigate these Dirac node arcs based topological semimetals.