Modeling the Fermi arc in underdoped cuprates

by M. R. Norman, A. Kanigiel, M. Randeria, U. Chatterjee, J. C. Campuzano

This article surveys the current state of our understanding of the "Fermi arcs" observed in the pseudogap phase in the cuprates. If you think about it for a moment, why would a Fermi surface simple end? There is, of course, the possibility that the arc is really a bannan shaped pocket, so that it forms a closed surface as predicted from weak coupling models. But there is also the possibility that this pseudogap phase requires new and creative ideas that take us well beyond Fermi liquid theory, to think of the strongly correlated regime in terms of new paradigms.

By following a modeling approach, wherein different theories give rise to certain simple forms for the fermion green function, this paper compares current theories of Fermi arcs with experiment. While no theory stands out as a clear winner, they are able to rule out some theories. By dividing the collection of theories into what they call q=0 theories (which are more or less theories of liquids) and q \neq 0 theories (theories where translational symmetry is broken, such as SDW, CDW, etc.) they conclude that those among the q \neq 0 set do not adequately compare with the data. While perhaps not so surprising, this article does a nice job of surving the current situation and provides a nice place to start for those interested in the subject.