title: Persistence of high-frequency spin fluctuations in overdoped superconducting La2-xSrxCuO4 (x=0.22).
abstract: We report a detailed inelastic neutron scattering study of the collective magnetic excitations of overdoped superconducting La(1.78)Sr(0.22)CuO(4) for the energy range 0-160 meV. Our measurements show that overdoping suppresses the strong response present for optimally doped La(2-x)Sr(x)CuO(4) which is peaked near 50 meV. The remaining response is peaked at incommensurate wave vectors for all energies investigated. We observe a strong high-frequency magnetic response for E approximately >80 meV suggesting that significant antiferromagnetic exchange couplings persist well into the overdoped part of the cuprate phase diagram.
authors.affiliation: H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom.
authors.forename: O J
authors.initials: OJ
authors.lastname: Lipscombe
authors.forename: S M
authors.initials: SM
authors.lastname: Hayden
authors.forename: B
authors.initials: B
authors.lastname: Vignolle
authors.forename: D F
authors.initials: DF
authors.lastname: McMorrow
authors.forename: T G
authors.initials: TG
authors.lastname: Perring