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arXiv · 2305.08603

Inversion symmetry breaking in bilayer multi-orbital Hubbard model with impurity approximation

Chenye Qin·Mi Jiang
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Abstract

We investigated the Cu/Ni-O$_2$ bilayer multi-orbital Hubbard model with Cu/Ni impurity approximation embedded in the O lattice by incorporating the 3d$^{8}$ multiplet structure coupled to a full O-2p band. For this simplified model of describing the local electronic structure of hole doped homo-bilayer Cu(Ni)O$_2$-Cu(Ni)O$_2$ and hetero-bilayer CuO$_2$-NiO$_2$, we demonstrate that the homo-bilayer system hosts rich phase diagram with inversion symmetry breaking between two layers at strong enough interlayer hybridization, especially the coexistence of two-hole singlet and triplet states in opposite layers. Besides, we show that the interlayer hybridization in hetero-bilayer systems destabilizes the Zhang-Rice singlets or 3d$^{8}$ triplets within each layer via charge transfer between layers. The relevance of these electronic redistribution to the bilayer or interface systems of cuprates and/or nickelates are discussed.

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Chenye Qin, Mi Jiang. 2023-05-15. Inversion symmetry breaking in bilayer multi-orbital Hubbard model with impurity approximation. https://doi.org/10.1103/physrevb.108.085137

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