Possible Strong Topological Insulator Phase in Li2 IrO 3
Abstract
Recently Na 2 Ir O3 , a layered 5 d transition metal oxide compound, was suggested to be a possible topological insulator (TI) based on the jeff = 1 / 2 states induced by the strong spin-orbit coupling of Ir 5 d states, but its realization has not been clarified yet. In search of the TI phase in transition metal oxides, we propose Li 2 Ir O3 to be a candidate for the three-dimensional strong TI. By carrying out Wannier function analysis based on first-principles calculations, we constructed a low energy effective Hamiltonian, which leads to a three-dimensional extension of the Kane-Mele model with third-nearest-neighbor hopping within the Ir honeycomb layer and a significant inter-layer coupling. The nature of spin-orbit coupled states near the Fermi level depends on the change of the trigonal crystal field driven by the lattice deformations. A competition between the third next-nearest-neighbor hopping parameter and the trigonal crystal field is found to play a key role in determining the topological character of Li 2 Ir O3 .
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2011
- Bibcode:
- 2011APS..MARX35006K