d-wave superconducting gap observed in protect-annealed electron-doped cuprate superconductors Pr1.3-xLa0.7CexCuO4

摘要

For electron-doped cuprates, the strong suppression of antiferromagnetic spin correlation by efficient reduction annealing by the "protect-annealing" method leads to superconductivity not only with lower Ce concentrations but also with higher transition temperatures. To reveal the nature of this superconducting state, we have performed angle-resolved photoemission spectroscopy measurements of protect-annealed electrondoped superconductors Pr1.3-xLa0.7CexCuO4 and directly investigated the superconducting gap. The gap was found to be consistent with d-wave symmetry, suggesting that strong electron correlation persists and hence antiferromagnetic spin fluctuations remain a candidate that mediates Copper pairing in the protect-annealed electron-doped cuprates.