title: Quantum oscillations in antiferromagnetic CaFe(2)As(2) on the brink of superconductivity.
abstract: We report quantum oscillation measurements on CaFe(2)As(2) under strong magnetic fields-recently reported to become superconducting under pressures of as little as a kilobar. The largest observed carrier pocket occupies less than 0.05% of the paramagnetic Brillouin zone volume-consistent with Fermi surface reconstruction caused by antiferromagnetism. On comparing several alkaline earth AFe(2)As(2) antiferromagnets (with A = Ca, Sr and Ba), the dependences of the Fermi surface cross-sectional area F(α) and the effective mass m(α)(*) of the primary observed pocket on the antiferromagnetic/structural transition temperature T(s) are both found to be consistent with the case for quasiparticles in a conventional spin-density wave model. These findings suggest that the recently proposed strain-enhanced superconductivity in these materials occurs within a broadly conventional spin-density wave phase.
authors.affiliation: Los Alamos National Laboratory, MS-E536, Los Alamos, NM 87545, USA.
authors.forename: N
authors.initials: N
authors.lastname: Harrison
authors.forename: R D
authors.initials: RD
authors.lastname: McDonald
authors.forename: C H
authors.initials: CH
authors.lastname: Mielke
authors.forename: E D
authors.initials: ED
authors.lastname: Bauer
authors.forename: F
authors.initials: F
authors.lastname: Ronning
authors.forename: J D
authors.initials: JD
authors.lastname: Thompson