NMR determination of Van Hove singularity and Lifshitz transitions in nodal-line semimetal ZrSiTe

TL;DR

This study uses NMR spectroscopy to investigate the electronic structure of ZrSiTe, revealing a van Hove singularity and Lifshitz transition linked to its nodal-line semimetal properties, with temperature and orientation-dependent effects.

Contribution

It provides the first NMR evidence of a van Hove singularity and Lifshitz transition in a nodal-line semimetal, highlighting the technique's sensitivity to topological electronic changes.

Findings

Identification of a van Hove singularity near the nodal line

Observation of a Lifshitz transition induced by temperature

Orientation-dependent scaling of band energies

Abstract

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 NMR shift and $(T_1T)^{-1}$ provides a quantitative measure of the dispersionless, quasi-2D 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 line width 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.