Graduate Student Seminar with Christopher Broyles on Massive Massless Fermions

The legacy of Majorana and Dirac has grown in recent years, with the explosion in geometric topology being applied to condensed matter systems. While originally hailed in particle physics, the Dirac equation has been used to model quasiparticle excitations with novel properties. Similarly, the Majorana equation, a special case where a particle is its own antiparticle, has been used to understand exotic vortex states in unconventional superconductors. When the system exhibits strongly correlated electrons, Dirac fermions originating from heavy fermion bands will vary from the nearly massless Graphene counterparts. In this presentation, I will discuss two novel superconductors which thrive with strongly correlated electrons. The first is CsV₃Sb₅, a topological superconductor candidate, which has been studied with quantum oscillations in large magnetic fields to reveal topologically non-trivial orbits. Secondly, the recently discovered heavy fermion superconductor, CeRh₂As₂, has been studied at large magnetic fields to understand a parity transition within the superconducting phase. Using these two materials, I will lead a discussion on the connection between topology and superconductivity in condensed matter systems.