We have applied nuclear magnetic resonance spectroscopy to study the distinctive network of nodal lines in the Dirac semimetal ZrSiTe. The low-$T$ behavior is dominated by a symmetry-protected nodal line, with NMR providing a sensitive probe of the diamagnetic response of the associated carriers. A sharp low-$T$ minimum in the NMR shift and ${\left(T_{1}T\right)}^{-1}$ provides a quantitative measure of the dispersionless, quasi-two-dimensional behavior of this nodal line. We also identify a Van Hove singularity closely connected to this nodal line, and an associated $T$-induced Lifshitz transition. A disconnect in the NMR shift and linewidth at this temperature indicates the change in electronic behavior associated with this topological change. These features have an orientation-dependent behavior indicating a field-dependent scaling of the associated band energies.

• Received 2 April 2021
• Accepted 30 June 2021

DOI:https://doi.org/10.1103/PhysRevB.104.L041105