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Title: Nature of the insulating ground state of the 5d postperovskite CaIrO3

In this study, the insulating ground state of the 5d transition metal oxide CaIrO3 has been classified as a Mott-type insulator. Based on a systematic density functional theory (DFT) study with local, semilocal, and hybrid exchange-correlation functionals, we reveal that the Ir t2g states exhibit large splittings and one-dimensional electronic states along the c axis due to a tetragonal crystal field. Our hybrid DFT calculation adequately describes the antiferromagnetic (AFM) order along the c direction via a superexchange interaction between Ir4+ spins. Furthermore, the spin-orbit coupling (SOC) hybridizes the t2g states to open an insulating gap. These results indicate that CaIrO3 can be represented as a spin-orbit Slater insulator, driven by the interplay between a long-range AFM order and the SOC. Such a Slater mechanism for the gap formation is also demonstrated by the DFT + dynamical mean field theory calculation, where the metal-insulator transition and the paramagnetic to AFM phase transition are concomitant with each other.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [2] ;  [3] ;  [1]
  1. Hanyang Univ., Seoul (Korea)
  2. Iowa State Univ., Ames, IA (United States)
  3. Iowa State Univ., Ames, IA (United States); Univ. of Science and Technology of China, Anhui (China)
Publication Date:
OSTI Identifier:
1234528
Report Number(s):
IS-J-8795
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US1600382
Grant/Contract Number:
2015R1A2A2A01003248; KSC-2014-C3-011; AC02-07CH11358; 61434002
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 115; Journal Issue: 9; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Ames Lab., Ames, IA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS