title: Unconventional superconductivity with a sign reversal in the order parameter of LaFeAsO1-xFx.
abstract: We argue that the newly discovered superconductivity in a nearly magnetic, Fe-based layered compound is unconventional and mediated by antiferromagnetic spin fluctuations, though different from the usual superexchange and specific to this compound. This resulting state is an example of extended s-wave pairing with a sign reversal of the order parameter between different Fermi surface sheets. The main role of doping in this scenario is to lower the density of states and suppress the pair-breaking ferromagnetic fluctuations.
authors.affiliation: Code 6393, Naval Research Laboratory, Washington, D.C. 20375, USA.
authors.forename: I I
authors.initials: II
authors.lastname: Mazin
authors.forename: D J
authors.initials: DJ
authors.lastname: Singh
authors.forename: M D
authors.initials: MD
authors.lastname: Johannes
authors.forename: M H
authors.initials: MH
authors.lastname: Du