title: Unusual relationship between magnetism and superconductivity in FeTe(0.5)Se(0.5).
abstract: We use neutron scattering to study magnetic excitations in crystals near the ideal superconducting composition of FeTe(0.5)Se(0.5). Two types of excitations are found, a resonance at (0.5,0.5,0) and incommensurate fluctuations on either side of this position. We show that the two sets of magnetic excitations behave differently with doping, with the resonance being fixed in position while the incommensurate excitations move as the doping is changed. These unusual results show that a common behavior of the low energy magnetic excitations is not necessary for pairing in these materials.
authors.affiliation: Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. mookhajr@ornl.gov
authors.forename: H A
authors.initials: HA
authors.lastname: Mook
authors.forename: M D
authors.initials: MD
authors.lastname: Lumsden
authors.forename: A D
authors.initials: AD
authors.lastname: Christianson
authors.forename: S E
authors.initials: SE
authors.lastname: Nagler
authors.forename: Brian C
authors.initials: BC
authors.lastname: Sales
authors.forename: Rongying
authors.initials: R
authors.lastname: Jin
authors.forename: Michael A
authors.initials: MA
authors.lastname: McGuire
authors.forename: Athena S
authors.initials: AS
authors.lastname: Sefat
authors.forename: D
authors.initials: D
authors.lastname: Mandrus
authors.forename: T
authors.initials: T
authors.lastname: Egami
authors.forename: Clarina
authors.initials: C
authors.lastname: dela Cruz