nd - m at . s up r - co n ] 4 D ec 2 00 4 Irradiation - induced suppression of the critical temperature in high - T c superconductors : Pair breaking versus phase fluctuations

Irradiation-induced suppression of the critical temperature in high-T c superconductors: Pair breaking versus phase fluctuations Experiments on the irradiation-induced suppression of the critical temperature in high-T c superconductors are analyzed within the mean-field Abrikosov-Gor'kov-like approach. It is shown that the experimental data for YBa 2 Cu 3 O 7−δ single crystals can be quantitatively explained by the pair breaking effects under the assumption of the combined effect of potential and spin-flip scattering on the critical temperature and with account for a non-pure d-wave superconducting order parameter. Particle irradiation is a powerful tool that gives an opportunity to modify the physical properties of superconductors. Irradiation-induced defects act as effective pinning centers [1], thus causing the critical current density to increase. Apart from the practical benefits, irradiation effects may be used to probe the fundamental characteristics of superconductors. For example, peculiarities of the disorder-induced suppression of the critical temperature T c are expected to depend on the pairing mechanism and the symmetry of the superconducting order parameter ∆(p). In this respect, a study of the response of high-T c cuprates to the intentionally incor