Scanning tunneling spectroscopic studies of cuprate superconductors revealed that the most eminent phenomena of hole-doped (p-type) cuprates, including the predominant dx2−y2 pairing symmetry, spin fluctuations and pseudogap, are absent in the infinite-layer electron-doped (n-type) cuprates Sr1−xLaxCuO2. The optimally doped Sr0.9La0.1CuO2 exhibits s-wave pairing symmetry, with a superconducting
... [Show full abstract] transition temperature Tc=43.0 K, a large energy gap Δ=13.0±1.0 meV, and no pseudogap in the normal state. The response of Sr0.9La0.1CuO2 to quantum impurities is also conventional, being less sensitive to non-magnetic impurities than to magnetic impurities, in sharp contrast to the strong effects induced by static non-magnetic impurities in the p-type cuprates. The dynamic injection of spin-polarized quasiparticles into the p-type cuprates is found to incur significant suppression of superconductivity, probably due to the strong influence on the spin fluctuations.