High resolution photoemission studies of strongly correlated systems

Peter Johnson

Physics Department, Brookhaven National Laboratory, Physics 510B, Upton NY 11973, USA

Recent technical advances in photoemission have allowed the technique to become an important probe of the low energy excitations in condensed matter systems. In this talk we focus on the application of the technique to studies of strongly correlated materials, including the the high Tc cuprates, the ruthenates and the cobaltates. We examine the nature of the excitations in these systems and their role in dimensional crossover. In the case of the ruthenate we show that there is a marked symmetry dependence in the scattering rates and that this symmetry dependence correlates at a microscopic level with transport measurements at a macroscopic level.