On the truncation of the Fermi surface in the spin gap phase
of underdoped cuprates

Maurice Rice

Theoretische Physik, EHT Zürich, CH 8093 Zürich, Switzerland

The most promising description of the anomalous properties of the superconducting state of underdoped cuprates is as a doped RVB phase[1].However it is difficult to extend the theory to finite temperatures and the normal spin gap phase.This phase can be approached from the weakly correlated limit using an RG scheme.It is also illuminating to study finite width ladders.These systems point to a partial truncation of the Fermi surface leaving arcs around the diagonal directions.The implications of this proposal will be discussed. 1.P.W.Anderson et al J.Phys.:Condens.Matter 16 R755 (2004)