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DS: Fachverband Dünne Schichten
DS 18: Transport: Topological Semimetals 1 (jointly with MA/TT)
DS 18.7: Vortrag
Dienstag, 21. März 2017, 11:15–11:30, HSZ 201
Topological metal with multiple Dirac cones and nodal line — •Ashis Kumar Nandy1, Alex Aperis1, M. Mofazzel Hosen2, Klauss Dimitri2, Pablo Maldonado1, Dariusz Kaczorowski3, Tomasz Durakiewicz4, Madhab Neupane2, and Peter M. Oppeneer1 — 1Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden — 2Department of Physics, University of Central Florida, Orlando, Florida, USA — 3Institute of Low Temp. & Structure Research, PAS, Wroclaw, Poland — 4Condens. Matter and Magnet Science Group, LANL, Los Alamos, USA
The extended class of topological materials includes topological (semi) metals that support non-trivial topological surface states in the form of one-dimensional Dirac lines or Fermi-arcs connecting two Weyl points. Here we study a ternary compound using a combination of systematic theoretical calculations and detailed angle-resolved photoemission spectroscopy (ARPES) measurements. In contrast to other topological materials, our first-principles calculations suggest that the band inversion is d−p type instead of the mostly observed s−p type band inversion. We identify multiple Dirac fermionic states at various binding energies. A Dirac cone is computed at the Γ point about 0.5 eV above the chemical potential. Most importantly, at around 1 eV below the Fermi level our calculations reveal a surface nodal line-like feature passing through the time-reversal invariant point M. Our systematic study suggests a new family of materials for exploring the coexistence and competition of multiple fundamental fermionic quantum states.