Date(s) - 11/02/2004
3:30 pm - 4:30 pm
Title: Nature of Charge Carriers in Bad Metals
Speaker: Dr. Barrett Wells
Institute: University of Connecticut
Location: ABB 102
High temperature superconductivity, colossal magneto-resistance, metal-insulator transitions are among the properties of transition metal oxides that have been the prominent in condensed matter physics over the past decade. A unifying theme of research into these materials is that they are in, or at least close to, a regime where the electronic properties are no longer determined by the traditional model of nearly free electrons, or quasiparticles. Some new type of many-electron physics is needed. However, actually measuring whether quasiparticles dominate the electron dynamics is difficult. A leading experiment that purports to do so is photoemission spectroscopy, particularly in the angular-resolved mode (ARPES). Unfortunately, there has been very little systematic study of what is a true signature of a quasiparticle in ARPES. This talk will review data on both simple metals and complex oxides to examine what is reliably known about measuring electron dynamics using this spectroscopy.