Crossing points of nodal lines in topological semimetals and Fermi surface of ZrSiS

Abstract

We investigate the electron spectra, Fermi surfaces and their characteristics near crossing points of two band-contact lines in nodal-line semimetals. In particular, the extremal cross-sectional areas, and the appropriate cyclotron masses are calculated. We also find the phase of the quantum oscillations associated with the electron orbits near the crossing point. The analysis of all these quantities is carried out both without and with consideration of the spin-orbit interaction. To illustrate the obtained results, we apply them to ZrSiS in which the crossing of the nodal lines occurs.

Nodal-line driven anomalous susceptibility in ZrSiS

“…3c we compare experimental QO effective masses with the one predicted by the model. The model predicts the effective mass of the cyclotron orbit around the neck of the electron tube-like pocket near the Σ to be m model eff = 3 eF/2E F , where F is the frequency of QOs of the neck orbitals, and E F is the Fermi energy of the pocket [33]. Using the above-presented values yields effective masses that are in excellent agreement with those obtained from the QOs.…”

“…F δ1 seems to be produced by the FS cross section located near the Σ point [28,33] which the two nodal lines intersect [19,22], see Fig. 1c.…”

“…We can show that the observed temperature dependence of the magnetic susceptibility is also caused by the electron states in the vicinity of the Σ point. Neglecting the spin-orbit interaction, the dispersion of the two contacting bands "c" and "v" in the vicinity of this crossing point can be approximately described by the following expression [33,34]:…”