The pairing mechanism in high-temperature superconductors, which are based on copper oxides, is still unresolved. The phonon and spin-fluctuation (SF) mechanisms are under the debate. The recent ARPES, NMR, optics, tunnelling and neutron scattering experiments - which give important informations on quasiparticle interaction, will be critically analyzed in the talk. It will be argued that the electron-phonon interaction is rather strong and pronounced at small momenta - the forward scattering peak. The latter is due to strong electronic correlations in these systems. The phonon mechanism in conjunction with a residual repulsion of quasiparticles can explain a number of normal state properties as well as d-wave pairing in these materials. It will be also argued that the SF interaction plays a secondary role in the optimally doped materials, which possesses the highest critical temperature.

Einladender: Prof. Dr. C. Falter

Ort: Wilhelm-Klemm-Str. 10, IG I, HS 2

Zeit: Mittwoch, 18. Juni 2003, 17:00 Uhr c.t.

Kolloquiums-Kaffee ab 16:45 Uhr vor dem Hörsaal

Im Auftrag der Hochschullehrer des Fachbereichs Physik
Prof. Dr. H. Mehrer