•Lothar Pintschovius
Forschungszentrum Karlsruhe, Institut fuer Festkoerperphysik, Postfach 3640, D-76021 Karlsruhe

There is widespread belief that the electronic structure of high temperature superconductors is characterized by an inhomogeneous distribution of charge and spin in which the spins on the copper atoms form antiferromagnetic stripes, separated by domain walls carrying the charge. Although theory suggests that stripe formation should be a universal property of the cuprates, solid experimental evidence for stripes has been found so far only for a particular compound (LNSCO), in which the stripes are static and are apparently detrimental to superconductivity. However, dynamic stripes are much more difficult to detect : one way is to look for fingerprints of the dynamic charge structure on the atomic vibrations. Indeed, recent results of phonon studies on the YBCO family have been interpreted as evidence of the formation of dynamic stripes. These results will be discussed in the light of our own extensive inelastic neutron scattering investigations on the same compounds