Pseudogaps, strange metals, and coherent superconductors:
The view from ARPES

Michael Norman

Argonnne National Laboratory, Materials Science Division, MSD-223, Argonne, IL 60439, USA

The phase diagram of cuprates reveals a rich variety of behavior, ranging from insulating to superconducting. The superconducting phase is surrounded by several phases of matter: (1) a "pseudogap" phase, (2) a "strange metal" phase, and (3) a "Fermi liquid" phase. These various phases are characterized by very different photoemission spectra, thus providing us with a unique window to peer into the nature of these novel states of matter.