FERMI-SURFACE INSTABILITIES AND UNUSUAL SPECTRAL PROPERTIES IN LOW-DIMENSIONAL SYSTEMS

Photoelectron spectroscopy can probe low energy electronic excitations in solids, with practical limitations set by the experimental energy and angular resolution. Appropriate conditions can now be achieved whi ch allow as to visualize changes in the electronic slates near the Fer mi surface at phase transitions, namely in tmo-dimensional materials. Quasi one-dimensional conductors are unique in their apparent failure to exhibit a clear metallic signature. This unusual spectroscopic beha vior might be the consequence of the singular nature of electronic cor relations in 1D.