title: Determining the short-range spin correlations in the spin-chain Li2CuO2 and CuGeO3 compounds using resonant inelastic x-ray scattering.
abstract: We report a high-resolution resonant inelastic soft x-ray scattering study of the quantum magnetic spin-chain materials Li(2)CuO(2) and CuGeO(3). By tuning the incoming photon energy to the oxygen K edge, a strong excitation around 3.5 eV energy loss is clearly resolved for both materials. Comparing the experimental data to many-body calculations, we identify this excitation as a Zhang-Rice singlet exciton on neighboring CuO(4) plaquettes. We demonstrate that the strong temperature dependence of the inelastic scattering related to this high-energy exciton enables us to probe short-range spin correlations on the 1 meV scale with outstanding sensitivity.
authors.affiliation: Research Department Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
authors.forename: Claude
authors.initials: C
authors.lastname: Monney
authors.forename: Valentina
authors.initials: V
authors.lastname: Bisogni
authors.forename: Ke-Jin
authors.initials: KJ
authors.lastname: Zhou
authors.forename: Roberto
authors.initials: R
authors.lastname: Kraus
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Strocov
authors.forename: Günter
authors.initials: G
authors.lastname: Behr
authors.forename: Jiři
authors.initials: J
authors.lastname: Málek
authors.forename: Roman
authors.initials: R
authors.lastname: Kuzian
authors.forename: Stefan-Ludwig
authors.initials: SL
authors.lastname: Drechsler
authors.forename: Steve
authors.initials: S
authors.lastname: Johnston
authors.forename: Alexandre
authors.initials: A
authors.lastname: Revcolevschi
authors.forename: Bernd
authors.initials: B
authors.lastname: Büchner
authors.forename: Henrik M
authors.initials: HM
authors.lastname: Rønnow
authors.forename: Jeroen
authors.initials: J
authors.lastname: van den Brink
authors.forename: Jochen
authors.initials: J
authors.lastname: Geck
authors.forename: Thorsten
authors.initials: T
authors.lastname: Schmitt