Van der Waals-Zeeman Colloquium

Tuesday, 27 Feb 2007, 16:00h

Electron- and spin-dynamics of unconventional cuprate superconductors

Prof. Joel Mesot
Laboratory for Neutron Scattering, ETH Zurich and Paul Scherrer Institute

As illustrated by their complex phase diagrams, the transition metal oxides possess remarkable electronic properties. It is not rare to observe a metal- insulator phase transition accompanied by orbital, magnetic and/or charge instabilities. In order to better identify the relevant interactions controlling their macroscopic properties, it is therefore crucial to obtain precise energy- and momentum-resolved information about the fundamental excitations in these materials. Neutron scattering and Angle Resolved Photoemission Spectroscopy (ARPES) provide powerful and complementary tools to investigate the subtle interplay that may exist between the spin and electronic degrees of freedom in the transition metal oxides.

Recent neutron scattering and ARPES results obtained on high-temperature superconductors as a function of doping, temperature and magnetic field will be presented. Issues such as the shape of the superconducting order parameter and its doping dependence, coherent vs incoherent excitations and implications for various theoretical models will be discussed.