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

TL;DR

This study uses de Haas-van Alphen quantum oscillations to investigate ZrSiS, revealing anisotropic Dirac bands, strong Zeeman splitting, nearly zero effective mass, and high quantum mobility of Dirac fermions, advancing understanding of topological semimetals.

Contribution

First systematic dHvA oscillation analysis of ZrSiS revealing detailed Dirac fermion properties and Zeeman effects in a topological nodal-line semimetal.

Findings

Revealed anisotropic Dirac bands in ZrSiS.

Found strong Zeeman splitting with a Landé g-factor of 38.

Identified nearly zero effective mass and high quantum mobility of Dirac fermions.

Abstract

Topological semimetals represent a new class of quantum materials hosting Dirac/Weyl fermions. The essential properties of topological fermions can be revealed by quantum oscillations. Here we present the first systematic de Haas-van Alphen (dHvA) oscillation studies on the recently discovered topological Dirac nodal-line semimetal ZrSiS. From the angular dependence of dHvA oscillations, we have revealed the anisotropic Dirac bands in ZrSiS and found surprisingly strong Zeeman splitting at low magnetic fields. The Land\'e g-factor estimated from the separation of Zeeman splitting peaks is as large as 38. From the analyses of dHvA oscillations, we also revealed nearly zero effective mass and exceptionally high quantum mobility for Dirac fermions in ZrSiS. These results shed light on the nature of novel Dirac fermion physics of ZrSiS.