Nearly massless Dirac fermions and strong Zeeman splitting in the nodal-line semimetal ZrSiS probed by de Haas–van Alphen quantum oscillations

Abstract

Topological semimetals harbor relativistic fermions featuring light effective mass, high mobility, and a nontrivial Berry phase. Quantum oscillations are an effective means to probe the properties of relativistic fermions. In the Dirac nodal-line semimetal ZrSiS, the extremely high Dirac fermion density gives rise to very strong de Haas--van Alphen quantum oscillations even at low magnetic fields, by which nearly massless Dirac fermions with surprisingly strong Zeeman effect are revealed.