Abstract
The discovery of a topological nodal-line (TNL) semimetal phase in ZrSiS has invigorated the study of other members of this family. Here, we present a comparative electronic structure study of (where , Se, Te) using angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations. Our ARPES studies show that the overall electronic structure of materials comprises the diamond-shaped Fermi pocket, the nearly elliptical-shaped Fermi pocket, and a small electron pocket encircling the zone center () point, the point, and the point of the Brillouin zone, respectively. We also observe a small Fermi surface pocket along the direction in ZrSiTe, which is absent in both ZrSiS and ZrSiSe. Furthermore, our theoretical studies show a transition from nodal-line to nodeless gapped phase by tuning the chalcogenide from S to Te in these material systems. Our findings provide direct evidence for the tunability of the TNL phase in material systems by adjusting the spin-orbit coupling strength via the anion.
- Received 17 August 2016
- Revised 1 November 2016
DOI:https://doi.org/10.1103/PhysRevB.95.161101
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