Electronic Structure and Minimal Models for Flat and Corrugated CuO Monolayers: An Ab Initio Study

Slobodchikov, A.A., Nekrasov, I.A., Begunovich, L.V., (...), Korshunov, M.M., Ovchinnikov, S.G.// Materials//


CuOCuO atomic thin monolayer (mlCuOmlCuO) was synthesized recently. Interest in the mlCuOmlCuO is based on its close relation to CuO2CuO2 layers in typical high temperature cuprate superconductors. Here, we present the calculation of the band structure, the density of states and the Fermi surface of the flat mlCuOmlCuO as well as the corrugated mlCuOmlCuO within the density functional theory (DFT) in the generalized gradient approximation (GGA). In the flat mlCuOmlCuO, the CuCu-3dx2y23��2−�2 band crosses the Fermi level, while the CuCu-3dxz,yz3���,�� hybridized band is located just below it. The corrugation leads to a significant shift of the CuCu-3dxz,yz3���,�� hybridized band down in energy and a degeneracy lifting for the CuCu-3dx2y23��2−�2 bands. Corrugated mlCuOmlCuO is more energetically favorable than the flat one. In addition, we compared the electronic structure of the considered CuOCuO monolayers with bulk CuOCuO systems. We also investigated the influence of a crystal lattice strain (which might occur on some interfaces) on the electronic structure of both mlCuOmlCuO and determined the critical strains of topological Lifshitz transitions. Finally, we proposed a number of different minimal models for the flat and the corrugated mlCuOmlCuO using projections onto different Wannier functions basis sets and obtained the corresponding Hamiltonian matrix elements in a real space