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

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Atomic thin copper oxide monolayers (mlCuO) are structurally related to CuO2 layers in cuprate superconductors.
• Understanding mlCuO electronic properties is crucial for exploring novel superconducting materials.

Purpose of the Study:

• To calculate and compare the electronic band structure, density of states, and Fermi surface of flat and corrugated mlCuO.
• To investigate the energetic favorability and electronic response to strain in mlCuO.
• To develop minimal models for mlCuO electronic Hamiltonians.

Main Methods:

• Density Functional Theory (DFT) with Generalized Gradient Approximation (GGA).
• Calculation of band structure, density of states, and Fermi surface.
• Analysis of electronic structure under crystal lattice strain.
• Wannier function projection for minimal model Hamiltonian derivation.

Main Results:

• Corrugated mlCuO is energetically more favorable than flat mlCuO.
• Corrugation significantly shifts hybridized bands and lifts degeneracy in Cu-3d bands.
• Electronic structures of mlCuO differ from bulk CuO.
• Critical strains for topological Lifshitz transitions in mlCuO were identified.
• Minimal models and Hamiltonian matrix elements for both mlCuO structures were obtained.

Conclusions:

• The electronic structure of mlCuO is sensitive to its geometric configuration (flat vs. corrugated).
• Corrugation plays a key role in modifying the electronic properties of mlCuO, potentially impacting superconductivity.
• mlCuO exhibits tunable electronic properties under strain, with implications for interface phenomena and topological transitions.