Quantum oscillation studies of the topological semimetal candidate ZrGeM (M = S, Se, Te)

The WHM-type materials (W = Zr/Hf/La, H = Si/Ge/Sn/Sb, M = O/S/Se/Te) have been predicted to be a large pool of topological materials. These materials allow for fine tuning of spin-orbit coupling, lattice constant, and structural dimensionality for various combinations of W, H, and M elements, thus providing an excellent platform to study how these parameters' tuning affects topological semimetal state. In this paper, we report high field quantum oscillation studies on ZrGeM (M = S, Se, and Te), from which we have revealed properties consistent with the theoretically predicted topological semimetal states. From the angular dependence of quantum oscillation frequency, we have also studied the Fermi surface topologies of these materials. Moreover, we have compared Dirac electron behavior between the ZrGeM and ZrSiM systems, which reveals deep insights to the tuning of Dirac state by spin-orbit coupling and lattice constants in the WHM system.