title: Q-dependence of spin excitations in high-T(C) cuprates from spin-phonon coupling.
abstract: An understanding of spin excitations in cuprates is essential since the mechanism of high-T(C) superconductivity might be linked to spin fluctuations. Band calculations for 'one-dimensional' unit cells of La(2)CuO(4) show larger coupling (spin-phonon coupling, SPC) between anti-ferromagnetic spin waves and O-phonons than for Cu- or La-phonons. When this result is applied to a two-dimensional, free-electron like band, it leads to an 'hourglass' shape of the spin excitation spectrum, as in recent experiments. Isotope shifts and doping dependences of the excitations are discussed.
authors.affiliation: Département de Physique de la Matière Condensée, University of Geneva, 24 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Jarlborg