title: Anisotropic three-dimensional magnetism in CaFe2As2.
abstract: Inelastic neutron scattering measurements of the magnetic excitations in CaFe2As2 indicate that the spin wave velocity in the Fe layers is exceptionally large and similar in magnitude to the cuprates. However, the spin wave velocity perpendicular to the layers is at least half as large that in the layer, so that the magnetism is more appropriately categorized as anisotropic three-dimensional, in contrast to the two-dimensional cuprates. Exchange constants derived from band structure calculations predict spin wave velocities that are consistent with the experimental data.
authors.affiliation: Department of Physics & Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: McQueeney
authors.forename: S O
authors.initials: SO
authors.lastname: Diallo
authors.forename: V P
authors.initials: VP
authors.lastname: Antropov
authors.forename: G D
authors.initials: GD
authors.lastname: Samolyuk
authors.forename: C
authors.initials: C
authors.lastname: Broholm
authors.forename: N
authors.initials: N
authors.lastname: Ni
authors.forename: S
authors.initials: S
authors.lastname: Nandi
authors.forename: M
authors.initials: M
authors.lastname: Yethiraj
authors.forename: J L
authors.initials: JL
authors.lastname: Zarestky
authors.forename: J J
authors.initials: JJ
authors.lastname: Pulikkotil
authors.forename: A
authors.initials: A
authors.lastname: Kreyssig
authors.forename: M D
authors.initials: MD
authors.lastname: Lumsden
authors.forename: B N
authors.initials: BN
authors.lastname: Harmon
authors.forename: P C
authors.initials: PC
authors.lastname: Canfield
authors.forename: A I
authors.initials: AI
authors.lastname: Goldman