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Title: Dynamic electronic correlation effects in NbO 2 as compared to VO 2

In this study we present a comparative investigation of the electronic structures of NbO 2 and VO 2 obtained within a combination of density functional theory and cluster-dynamical mean-field theory calculations. We investigate the role of dynamic electronic correlations on the electronic structure of the metallic and insulating phases of NbO 2 and VO 2, with a focus on the mechanism responsible for the gap opening in the insulating phases. For the rutile metallic phases of both oxides, we obtain that electronic correlations lead to a strong renormalization of the t 2g subbands, as well as the emergence of incoherent Hubbard subbands, signaling that electronic correlations are also important in the metallic phase of NbO 2. Interestingly, we find that nonlocal dynamic correlations do play a role in the gap formation of the [body-centered-tetragonal (bct)] insulating phase of NbO 2, by a similar physical mechanism as that recently proposed by us in the case of the monoclinic (M 1) dimerized phase of VO 2. Finally, although the effect of nonlocal dynamic correlations in the gap opening of bct phase is less important than in the (M 1 and M 2) monoclinic phases of VO 2, their presence indicates that themore » former is not a purely Peierls-type insulator, as it was recently proposed.« less
Authors:
 [1] ;  [2] ;  [3] ;  [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.; Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy
  2. Federal Univ. of Minas Gerais, Belo Horizonte (Brazil). Dept. of Physics
  3. Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy
Publication Date:
Report Number(s):
BNL-203224-2018-JAAM
Journal ID: ISSN 2469-9950
Grant/Contract Number:
SC0012704; DMR-1405303; DMR-1308141
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 96; Journal Issue: 19; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE; National Science Foundation (NSF); National Council for Scientific and Technological Development (CNPq) (Brazil); Coordination of Improvement of Higher Education Personnel (CAPES) (Brazil); Minas Gerais State Agency for Research and Development (FAPEMIG) (Brazil)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1425077