Optimizing Superconductivity: From Cuprates via Nickelates to Palladates

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Cuprate and nickelate superconductors exhibit complex electronic properties.
• Understanding the fundamental mechanisms driving superconductivity is crucial for discovering new materials.

Purpose of the Study:

• To comprehensively study superconducting instability in the single-band Hubbard model.
• To identify optimal conditions for high superconducting transition temperatures (Tc).
• To evaluate the suitability of cuprates, nickelates, and palladates based on theoretical predictions.

Main Methods:

• Utilized the dynamical vertex approximation to calculate the spectrum and Tc.
• Investigated the influence of filling, Coulomb interaction, and hopping parameters.
• Integrated first-principles calculations for material-specific analysis.

Main Results:

• Identified an optimal regime for high Tc at intermediate coupling, moderate Fermi surface warping, and low hole doping.
• Found that neither cuprates nor nickelates are near this optimum within the single-band Hubbard model.
• Highlighted RbSr2PdO3 and A'2PdO2Cl2 (A'=Ba0.5La0.5) palladates as potentially optimal, while NdPdO2 is too weakly correlated.

Conclusions:

• The single-band Hubbard model provides a framework for understanding superconducting properties.
• Palladates represent promising candidates for high-temperature superconductivity.
• Further research is needed to explore the superconducting potential of these materials.