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Title: Criteria for Directly Detecting Topological Fermi Arcs in Weyl Semimetals

The recent discovery of the first Weyl semimetal in TaAs provides the first observation of a Weyl fermion in nature and demonstrates a novel type of anomalous surface state, the Fermi arc. Like topological insulators, the bulk topological invariants of a Weyl semimetal are uniquely fixed by the surface states of a bulk sample. We present a set of distinct conditions, accessible by angle-resolved photoemission spectroscopy (ARPES), each of which demonstrates topological Fermi arcs in a surface state band structure, with minimal reliance on calculation. We also apply these results to TaAs and NbP. For the first time, we rigorously demonstrate a nonzero Chern number in TaAs by counting chiral edge modes on a closed loop. Furthermore, we show that it is unreasonable to directly observe Fermi arcs in NbP by ARPES within available experimental resolution and spectral linewidth. Our results are general and apply to any new material to demonstrate a Weyl semimetal.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [2] ;  [2] ;  [1] ;  [1] ;  [5] ;  [6] ;  [3] ;  [7] ;  [8] ;  [2] ;  [3] ;  [1]
  1. Princeton Univ., NJ (United States). Lab. for Topological Quantum Matter and Spectroscopy
  2. National Univ. of Singapore (Singapore). Centre for Advanced 2D Materials and Graphene Research Centre and Dept. of PHysics
  3. Peking Univ., Beijing (China). International Center for Quantum Materials
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Condensed Matter and Magnet Science Group; Univ. of Central Florida, Orlando, FL (United States). Dept. of Physics
  5. Princeton Univ., NJ (United States). Lab. for Topological Quantum Matter and Spectroscopy; National Tsing Hua Univ., Hsinchu (Taiwan). Dept. of Physics
  6. National Univ. of Singapore (Singapore). Centre for Advanced 2D Materials and Graphene Research Centre and Dept. of PHysics; Northeastern Univ., Boston, MA (United States). Dept. of Physics
  7. Northeastern Univ., Boston, MA (United States). Dept. of Physics
  8. National Tsing Hua Univ., Hsinchu (Taiwan). Dept. of Physics; Academia Sinica, Taipei (Taiwan). Inst. of Physics
Publication Date:
Report Number(s):
LA-UR-17-22127
Journal ID: ISSN 0031-9007; PRLTAO
Grant/Contract Number:
AC52-06NA25396; FG02-07ER46352; AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 116; Journal Issue: 6; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Material Science
OSTI Identifier:
1352386
Alternate Identifier(s):
OSTI ID: 1237788