title: Protected nodes and the collapse of Fermi arcs in high-T{c} cuprate superconductors.
abstract: Angle resolved photoemission on underdoped Bi2Sr2CaCu2O8 reveals that the magnitude and d-wave anisotropy of the superconducting state energy gap are independent of temperature all the way up to T{c}. This lack of T variation of the entire k-dependent gap is in marked contrast to mean field theory. At T{c} the point nodes of the d-wave gap abruptly expand into finite length "Fermi arcs." This change occurs within the width of the resistive transition, and thus the Fermi arcs are not simply thermally broadened nodes but rather a unique signature of the pseudogap phase.
authors.affiliation: Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: A
authors.initials: A
authors.lastname: Kanigel
authors.forename: U
authors.initials: U
authors.lastname: Chatterjee
authors.forename: M
authors.initials: M
authors.lastname: Randeria
authors.forename: M R
authors.initials: MR
authors.lastname: Norman
authors.forename: S
authors.initials: S
authors.lastname: Souma
authors.forename: M
authors.initials: M
authors.lastname: Shi
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Raffy
authors.forename: J C
authors.initials: JC
authors.lastname: Campuzano