Theoretical Study of Electron Correlation Driven Superconductivity in Systems with Coexisting Wide and Narrow Bands

This book deals with the study of superconductivity in systems with coexisting wide and narrow bands. It has been previously suggested that superconductivity can be enhanced in systems with coexisting wide and narrow bands when the Fermi level is near the narrow band edge. In this book, the authors study two problems concerning this mechanism in order to: (a) provide a systematic understanding of the role of strong electron correlation effects, and (b) propose a realistic candidate material which meets the ideal criteria for high-Tc superconductivity.

Regarding the role of strong correlation effects, the FLEX+DMFT method is adopted. Based on systematic calculations, the pairing mechanism is found to be indeed valid even when the strong correlation effect is considered within the formalism. In the second half of the book, the authors propose a feasible candidate material by introducing the concept of the “hidden ladder” electronic structure, arising from the combination of the bilayer lattice structure and the anisotropic orbitals of the electrons. As such, the book contributes a valuable theoretical guiding principle for seeking unknown high-Tc superconductors.

• High Temperature Superconductivity in Cuprates
• Electron Correlation Driven Cooper Pairs
• FLEX+DMFT Method for Superconductivity
• Hidden Ladders in Ruddlesden-Popper type Layered Perovskite
• Tight-Binding Model from First-Principles Calculations

• Department of Physics, Osaka University, Osaka, Japan

  Daisuke Ogura

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