Quantum oscillations in chiral topological semimetal PdGa

Chiral structured semimetals have recently been predicted to host unusual fermionic excitations, such as Dirac, Weyl, and Majorana fermions, with symmetries not observed in high-energy physics. The lack of both inversion and mirror symmetry in chiral crystal structures has been predicted to create fermionic excitations with large topological charge, extended Fermi arc surface states, and unusual magneto-transport behavior. Four-fold independent Fermi arcs have been reported on the surface of chiral structured materials with space group P213. Recent angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy investigations performed on B20-structured PdGa have claimed to observe these four-fold independent Fermi arcs on the surface, with band splitting due to relatively strong spin-orbit coupling. Following the predictions of unusual fermions in this class of materials, we synthesized PdGa single crystals using flux growth and the Bridgman technique. In this talk, I will present recent observations of de Haas-van Alphen (dHvA) oscillations in PdGa, associated with a band thought to host unconventional chiral fermions, and the changes we observe that suggest a topological shift at high field.