title: Softening of Cu-O bond stretching phonons in tetragonal HgBa2CuO4+delta.
abstract: Phonons in nearly optimally doped HgBa(2)CuO(4+delta) were studied by inelastic x-ray scattering. The dispersion of the low-energy modes is well described by a shell model, while the Cu-O bond stretching mode at high energy shows strong softening towards the zone boundary, which deviates strongly from the model. This seems to be common in the hole-doped high-T(c) superconducting cuprates, and, based on this work, not related to a lattice distortion specific to each material.
authors.affiliation: Superconductivity Research Laboratory, International Superconductivity Technology Center, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Uchiyama
authors.forename: A Q R
authors.initials: AQ
authors.lastname: Baron
authors.forename: S
authors.initials: S
authors.lastname: Tsutsui
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: W-Z
authors.initials: WZ
authors.lastname: Hu
authors.forename: A
authors.initials: A
authors.lastname: Yamamoto
authors.forename: S
authors.initials: S
authors.lastname: Tajima
authors.forename: Y
authors.initials: Y
authors.lastname: Endoh