Control of Superconducting Correlations in High-T_c Cuprates

A strategy to enhance d-wave superconducting correlations is proposed based on our numerical study of correlated electron models for high-T_c cuprates. We observe that the pairing is enhanced when the single-electron level around (π, 0) is close to the Fermi level E_F, while the d-wave pairing interaction itself contains elements to disfavor the pairing due to a shift of the (π, 0)-level. Angle-resolved photoemission results for the cuprates are consistently explained in the presence of the d-wave pairing interaction. We propose to tune the (π, 0)-level. under many-body effects, to E_F through optimal design of the band structure.