Superconductivity enhancement and particle-hole asymmetry: interplay with electron attraction in doped Hubbard model
The study investigates how adding an attractive interaction (V) affects superconductivity and charge density waves in a doped Hubbard model. In electron-doped systems (t' > 0), moderate attraction boosts superconductivity while suppressing charge stripes, leading to a clear SC phase. The critical attraction strength for SC dominance is found around Vc ≈ 0.7.