Searching for a promising topological Dirac nodal-line semimetal by angle resolved photoemission spectroscopy

Abstract Topological semimetals, in which conduction and valence bands cross each other at either discrete points or along a closed loop with symmetry protected the momentum space, exhibited great potential applications of optical devices as well heterogeneous catalysts antiferromagnetic spintronics, especially when crossing points/lines matches Fermi level ( E F ). It is intriguing to find ‘ideal’ topological semimetal material, has band structure Dirac band-crossing located without intersected by extraneous bands. Here, using angle resolved photoemission spectroscopy, we investigate so-called ‘square-net’ material ZrGeS. The Brillouin zone (BZ) mapping shows surface ZrGeS composed diamond-shaped nodal line center BZ small electron-like pockets around X point. right , clearly linear dispersions within large energy range >1.5 eV below obtained velocities effective masses Γ–X, Γ–M M–X high directions were 4.5–5.9 Å 0–0.50 m e revealing an anisotropic electronic property. Our results suggest that ZrGeS, promising semimetal, could provide platform Dirac-fermions related physics devising.