Superconductivity from flat dispersion designed in doped mott insulators
Routes to enhance superconducting instability are explored for doped Mott insulators. With the help of insight for criticalities of metal-insulator transitions, geometrical design of lattice structure is proposed to control the instability. A guideline is to explicitly make flat band dispersions near the Fermi level without suppressing two-particle channels. In a one-dimensional model, numerical studies show that our prescription with finite-ranged hoppings realizes large enhancement of spin-gap and pairing dominant regions. We also propose several multiband systems, where the pairing is driven by intersite Coulomb repulsion.
Imada
M
Institute for Solid State Physics, University of Tokyo, Roppongi, Minato-ku, Tokyo 106-8666, Japan.
Kohno
M