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 Karl Franzens University Graz

Graz University of Technology 

Electron pairing in high temperature superconductors
Prof. Walter Metzner
Max Planck Institute for Solid State Research, Stuttgart
17:15 - 18:15 Tuesday 15 December 2009 TUG P2

The formation of Cooper pairs is a characteristic feature of all known superconductors. In conventional superconductors the attractive interaction leading to this pairing of electrons is generated by the exchange of phonons.

The high transition temperatures of the cuprate based superconductors discovered since 1986 can hardly be explained by the conventional phonon mediated pairing mechanism. Therefore, it is most likely that the pairing
of electrons in these materials is due to subtle correlations induced by the (repulsive!) Coulomb interaction. Calculations
performed for interacting electron models show that such a counterintuitive ''attraction from repulsion'' is indeed
possible. Since the discovery of high temperature superconductors various ideas on the relevant pairing mechanism have been proposed. The theoretical understanding
is strongly influenced by specific, often ingenious,
experiments.


The talk will provide an overview of general concepts and the present state of research on electron pairing in high
temperature superconductors.