Out-of-plane impurities induce deviations from the monotonic d-wave superconducting gap of cuprate superconductors

The electronic structure of cuprate superconductors is studied within the kinetic-energy-driven superconducting mechanism in the presence of out-of-plane impurities. With increasing impurity concentration, although both superconducting coherence peaks around the nodal and antinodal regions are suppressed, the position of the leading-edge midpoint of the electron spectrum around the nodal region remains at the same position, whereas around the antinodal region it is shifted toward higher binding energies, this leads to a strong deviation from the monotonic d-wave superconducting gap in the out-of-plane impurity-controlled cuprate superconductors.