Nodeless High-Tc Superconductivity in the Highly Overdoped CuO2 Monolayer

Abstract

We study the electronic structure and superconductivity in a CuO2 monolayer grown recently on the d-wave cuprate superconductor Bi2Sr2CaCu2O8+δ. Density functional theory calculations indicate a significant charge transfer across the interface such that the CuO2 monolayer is heavily overdoped into the hole-rich regime yet inaccessible in bulk cuprates. We show that both the Cu dx2−y2 and d3z2−r2 orbitals become important and the Fermi surface contains one electron and one hole pocket associated with the two orbitals, respectively. Constructing a minimal correlated two-orbital model for the eg complex, we show that the spin-orbital exchange interactions produce a nodeless superconductor with extended s-wave pairing symmetry and a pairing energy gap comparable to the bulk d-wave gap, in agreement with recent experiments. The findings point to a direction of realizing new high-Tc superconductors in ozone grown transition-metal-oxide monolayer heterostructures.

Source-reported materials — not catalogue approval

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