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Title: Strong topological metal material with multiple Dirac cones

We report a new, cleavable, strong topological metal, Zr 2Te 2P, which has the same tetradymite-type crystal structure as the topological insulator Bi 2Te 2Se. Instead of being a semiconductor, however, Zr 2Te 2P is metallic with a pseudogap between 0.2 and 0.7 eV above the Fermi energy (E F). Inside this pseudogap, two Dirac dispersions are predicted: one is a surface-originated Dirac cone protected by time-reversal symmetry (TRS), while the other is a bulk-originated and slightly gapped Dirac cone with a largely linear dispersion over a 2 eV energy range. A third surface TRS-protected Dirac cone is predicted, and observed using angle-resolved photoemission spectroscopy, making Z r2Te 2P the first system, to our knowledge, to realize TRS-protected Dirac cones at M¯ points. The high anisotropy of this Dirac cone is similar to the one in the hypothetical Dirac semimetal BiO 2. As a result, we propose that if E F can be tuned into the pseudogap where the Dirac dispersions exist, it may be possible to observe ultrahigh carrier mobility and large magnetoresistance in this material.
Authors:
 [1] ;  [2] ;  [3] ;  [1] ;  [1] ;  [1]
  1. Princeton Univ., Princeton, NJ (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. Princeton Univ., Princeton, NJ (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
BNL-111979-2016-JA
Journal ID: ISSN 2469-9950; PRBMDO; R&D Project: PM016; KC0202020
Grant/Contract Number:
SC00112704; AC02-05CH11231; SC0012704
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 4; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1246802
Alternate Identifier(s):
OSTI ID: 1235963