Anisotropic quantum transport in ZrSiS probed by high-field torque magnetometry

Here, we present electronic structures of the topological nodal line semimetal ZrSiS along in-plane and out-of-plane directions using high-field torque magnetometry. The torque signal measured up to 35 T exhibited clear de Haas-van Alphen (dHvA) oscillations in both directions; however, the angular dependence of the frequencies along these directions is quite different. Our Berry phase (${\mathrm{\ensuremath{\Phi}}}_{\text{B}}$) calculations using the Landau level fan diagram show that ${\mathrm{\ensuremath{\Phi}}}_{\text{B}}\phantom{\rule{0.16em}{0ex}}\ensuremath{\approx}\ensuremath{\pi}$, confirming the nontrivial topology of ZrSiS. Using Lifshitz-Kosevich and Dingle temperature analyses on the temperature and field-dependent dHvA oscillations data, we calculated all relevant physical parameters. We found that Dirac fermions exhibit anisotropic transport properties along the in-plane and out-of-plane directions, with in-plane fermions having a longer scattering time, a higher mean free path, and greater quantum mobility. To explain the experimental results, we computed the electronic bands and Fermi surface of ZrSiS using ab initio density functional theory. The electronic bands revealed multiple Dirac cones near the Fermi level, displaying linear dispersion over an energy range of 2 eV. The possible dHvA frequencies were computed using Onsager's relation, and the calculated frequencies closely align with the experimental dHvA frequencies. The anisotropic quantum transport properties presented here provide valuable insights into the unique Dirac fermion physics inherent in ZrSiS.