In the hole-doped cuprate superconductors, the superconducting transition
temperature Tc exhibits a dome-like feature against the doping rate. By
contrast, recent experiments reveal that Tc in the electron-doped systems
monotonically increases as the doping is reduced, at least up to a very small
doping rate. Here we show that this asymmetry is reproduced by performing a
two-particle self-consistent analysis for the three-band model of the CuO2
plane. This is explained as a combined effect of the intrinsic electron-hole
asymmetry in systems comprising Cu3d and O2p orbitals and the
band-filling-dependent vertex correction.Comment: 5 pages, 5 figures, 2 table