Irradiation-induced disorder in high-Tc cuprates: Electronic band structure study

We used thermal neutron irradiation to produce disorder in Bi-2212 single crystals (Tc=85 K), at a constant carrier density. The irradiated samples were insulators. High-temperature superconductivity with a lower Tc than prior to irradiation could be restored by a low-temperature annealing. We performed angle-resolved photoemission investigation on both unannealed (insulating) and annealed (superconducting) samples in order to study the corresponding changes in electronic structure. We observed a strong suppression of the spectral weight near the Fermi energy with increasing disorder. Our results demonstrate that effects related to disorder cannot be neglected in the interpretation of the spectral properties of cuprates.