Interplay of frustration, magnetism, charge ordering, and covalency in the ionic Hubbard model for Na0.5 CoO2

Physical Review B - Condensed Matter and Materials Physics

Volumn 79, Issue 16, 2009, Pages

  Merino, Jaime ^a   Powell, B J ^b   McKenzie, Ross H ^b  

^a UNIVERSIDAD AUTÓNOMA DE MADRID   (Spain)

^b UNIVERSITY OF QUEENSLAND   (Australia)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 66249138814     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.79.161103     Document Type: Article

References (44)

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32. Atomistic calculations give t=- (0.08-0.14) eV, U=2.5-2.8 eV, and Δ=0.03-0.16 eV (Refs.). Further, CoO2, which is described by model 1 at half filling with Δ=0, is a strongly correlated metal rather than a Mott insulator. This suggests U/ |t| 12-15, the critical value for a Mott insulator on the triangular lattice (Refs.).
33. The tight-binding band structure of model 1 consists of two bands due to hybridization between A and B sites. At 3/4 filling, for t>0 and any non-zero Δ, the lower band is filled and the upper band is half filled, while for t<0 the lower band is filled for |Δ| 0.64t.
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