Nodeless High- Tc Superconductivity in the Highly Overdoped CuO2 Monolayer

We study the electronic structure and superconductivity in CuO_2monolayer grown recently on dwave cuprate superconductor Bi_2r_2aCu_2_{8+\delta} Density functional theory calculations indicate significant charge transfer across the interface such that the CuO_2monolayer is heavily overdoped into the hole-rich regime yet inaccessible in bulk cuprates. We show that both the Cu d_{x^2-y^2}and d_{3z^2-r^2}orbitals become...