Dresden 2020 – scientific programme
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O: Fachverband Oberflächenphysik
O 122: Topology and Symmetry Protected Materials II
O 122.8: Talk
Friday, March 20, 2020, 12:15–12:30, WIL A317
Experimental observation and spin texture of a Dirac node arc in tetradymite topological metals — •Ji Dai1, 2, Emmanouil Frantzeskakis1, Kuan-Wen Chen3, 4, Franck Fortuna1, Taichi Okuda5, François Bertran6, Julien Rault6, Patrick Le Fèvre6, Ryan Baumbach3, 4, and Andrés Felipe Santander-Syro1 — 1CSNSM, Université Paris-Sud, Orsay, France — 2Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland — 3National High Magnetic Field Laboratory, Florida State University, USA — 4Department of Physics, Florida State University, USA — 5Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hrioshima, Japan — 6Synchrotron SOLEIL, Gif-sur-Yvette, France
Topological metals of the tetradymite family M2Te2X (with M=Ti, Zr or Hf and X=P or As) have been recently proposed to possess multiple Dirac cones, different topological characteristics and a Dirac node arc [1-4]. Here we use spin- and angle-resolved photoemission spectroscopy to directly probe the electronic dispersion and -for the first time- the spin texture of the topological surface states in Hf2Te2P and Ti2Te2P. Our results confirm a persistent spin polarization of these states along a high symmetry direction of the Brillouin zone, thereby establishing the presence of a Dirac node arc, regardless of the weak (Hf2Te2P) or strong (Ti2Te2P) character of the topological invariant.
[1] H. Ji, et al., Physical Review B 93, 045315 (2016).
[2] K.-W. Chen, et al., Physical Review B 97, 165112 (2018).
[3] M. M. Hosen, et al., Nature Communication 9, 3002 (2018).