The experimental discovery of the topological Dirac semimetal establishes a platform to search for various exotic quantum phases in real materials. ZrSiS-type materials have recently emerged as topological nodal-line semimetals where gapped Dirac-like surface states are observed. Here, we present a systematic angle-resolved photoemission spectroscopy (ARPES) study of ZrGeTe, a nonsymmorphic symmetry protected Dirac semimetal. We observe two Dirac-like gapless surface states at the same Xˉ point of the Brillouin zone. Our theoretical analysis and first-principles calculations reveal that these are protected by crystalline symmetry. Hence, ZrGeTe appears as a rare example of a naturally fine tuned system where the interplay between symmorphic and non-symmorphic symmetry leads to rich phenomenology, and thus opens for opportunities to investigate the physics of Dirac semimetallic and topological insulating phases realized in a single material.
@article{arxiv.1711.08011,
title = {Observation of Gapless Dirac Surface States in ZrGeTe},
author = {M. Mofazzel Hosen and Klauss Dimitri and Alex Aperis and Pablo Maldonado and Ilya Belopolski and Gyanendra Dhakal and Firoza Kabir and Christopher Sims and M. Zahid Hasan and Dariusz Kaczorowski and Tomasz Durakiewicz and Peter M. Oppeneer and Madhab Neupane},
journal= {arXiv preprint arXiv:1711.08011},
year = {2018}
}