Lattice dynamics and electron-phonon coupling in superconducting HgBa2CuO4 investigated by inelastic neutron scattering

Phonon dispersion in the one-layer cuprate HgBa2CuO4+

“…Most of the parameters of table 1 are in agreement with the values reported by Renker et al (1996) and Chaplot et al (1995). Nevertheless, some discrepancies have to be mentioned: the Born-Mayer potentials for the Ba-O(1) and Ba-O(2) bonds are different from the Ba-O potential in Chaplot et al (1995), with the first radius r κ,κ slightly shorter and the second slightly larger, according to Renker et al (1996).…”

“…Such a size is insufficient for inelastic neutron scattering (INS), that is the standard technique used to measure the dispersion of phonons. For this reason, phonon data on this system were, up to now, limited to the ones obtained by INS performed on powders, which gives a measure of the phonon density of state (PDOS) (Renker et al 1996), and by Raman spectroscopy (Hur et al 1993, Krantz et al 1994, Lee et al 1994, Ren et al 1994, Yang et al 1995, Zhou et al 1996a, Poulakis et al 1999and Cai et al 2001. These experimental results have been analysed using a shell model calculation by Renker et al (1996) and Stachiotti et al (1995), who have also determined the zone centre frequencies from frozen-phonon first principles calculations.…”

Bond Stretching Phonon Softening and Kinks in the Angle-Resolved Photoemission Spectra of Optimally DopedBi2Sr1.6La0.4Cu2O6+<

“…All our attempts to find a better set of potentials compatible with previous established potential sets [27] failed. Several factors might be responsible for such disagreement, including: (I) the charge distribution and bonds of the high Z atoms containing f electrons (Bi) are very difficult to model accurately [28], and (II) the one-dimensional incommensurate superstructure along the b-axis [29] which is neglected in the calculation.…”

Softening of Cu-O Bond Stretching Phonons in TetragonalHgBa2CuO4+δ

“…2 along with a simple shell model similar to that used previously to simulate cuprate phonon dispersion [6,11,17]. The parameters for this model were based on a common set for the cuprates [17], with slight modification for Hg1201 [18], and to fit the Raman A 1g data [19], and (though independently determined) were similar to those used in ref. [14].…”