2017/11/20 by M. Mofazzel Hosen, Klauss Dimitri, Ashis K. Nandy +11
Chemistry · Materials Science · Physics and Astronomy · #Advanced Physical and Chemical Molecular Interactions #Angle-resolved photoemission spectroscopy #Chemical and Physical Properties of Materials #Dirac (video compression format) #Dirac fermion #Fermi level #Photoemission spectroscopy #Surface (topology) #Surface states #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41467-018-05233-1
published as Nature Communications 9, 3002 (2018) · 8 pages, 5 figures
arxiv created 2017/11/20 · openalex publication_date 2018/07/26 · arxiv updated 2018/08/07 · openalex created_date 2019/07/30 · openalex updated_date 2026/08/05
Abstract Among the quantum materials that have recently gained interest are the topological insulators, wherein symmetry-protected surface states cross in reciprocal space, and the Dirac nodal-line semimetals, where bulk bands touch along a line in k-space. However, the existence of multiple fermion phases in a single material has not been verified yet. Using angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations, we systematically study the metallic material Hf 2 Te 2 P and discover properties, which are unique in a single topological quantum material. We experimentally observe weak topological insulator surface states and our calculations suggest additional strong topological insulator surface states. Our first-principles calculations reveal a one-dimensional Dirac crossing—the surface Dirac-node arc—along a high-symmetry direction which is confirmed by our ARPES measurements. This novel state originates from the surface bands of a weak topological insulator and is therefore distinct from the well-known Fermi arcs in semimetals.