Quantum oscillations of the magnetic torque in the nodal-line Dirac semimetal ZrSiS

TL;DR

This study uses high-field quantum oscillation measurements to map the Fermi surface of ZrSiS, revealing magnetic breakdown orbits and providing new insights into its electronic structure.

Contribution

It presents the first detailed analysis of quantum oscillations in ZrSiS, identifying magnetic breakdown orbits and clarifying the Fermi surface topology.

Findings

High-frequency oscillations originate from magnetic breakdown orbits.

The QO frequency from the $eta$ pocket is 591 T.

Most low-frequency QO can be explained by magnetic breakdown involving the $eta$ pocket.

Abstract

We report a study of quantum oscillations (QO) in the magnetic torque of the nodal-line Dirac semimetal ZrSiS in the magnetic fields up to 35 T and the temperature range from 40 K down to 2 K, enabling high resolution mapping of the Fermi surface (FS) topology in the $k_z=\pi$ (Z-R-A) plane of the first Brillouin zone (FBZ). It is found that the oscillatory part of the measured magnetic torque signal consists of low frequency (LF) contributions (frequencies up to 1000 T) and high frequency (HF) contributions (several clusters of frequencies from 7-22 kT). Increased resolution and angle-resolved measurements allow us to show that the high oscillation frequencies originate from magnetic breakdown (MB) orbits involving clusters of individual $\alpha$ hole and $\beta$ electron pockets from the diamond shaped FS in the Z-R-A plane. Analyzing the HF oscillations we have unequivocally shown that the QO frequency from the dog-bone shaped Fermi pocket ($\beta$ pocket) amounts $\beta=591(15)$ T. Our findings suggest that most of the frequencies in the LF part of QO can also be explained by MB orbits when intraband tunneling in the dog-bone shaped $\beta$ electron pocket is taken into account. Our results give a new understanding of the novel properties of the FS of the nodal-line Dirac semimetal ZrSiS and sister compounds.