Related papers: Sharp optical phonon softening close to optimal do…
Inelastic neutron scattering has been used to study the in-plane Cu-O bond-stretching mode in oxygen doped La$_{1.94}$Sr$_{0.06}$CuO$_{4.035}$ ($T_c = 38\,\text{K}$) and La$_2$CuO$_{4+\delta}$ ($T_c = 43\,\text{K}$). Similar to results from…
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…
In superconducting copper oxides some Cu-O bond-stretching phonons around 70meV show anomalous giant softening and broadening of electronic origin and electronic dispersions have large renormalization kinks near the same energy. These…
The dispersion of the Cu-O bond-stretching vibrations in overdoped La$_{1.7}$Sr$_{0.3}$CuO$_4$ (not superconducting) has been studied by high resolution inelastic neutron scattering. It was found that the doping-induced renormalization of…
We present a comprehensive study of the phonon dispersion in an underdoped, superconducting Ca$_{2-x}$CuO$_2$Cl$_2$ crystal. We interpret the results using lattice dynamical calculations based on a shell model, and we compare the results,…
We measure the dispersion of the Cu-O bond-stretching phonon mode in the high-temperature superconducting parent compound Ca$_2$CuO$_2$Cl$_2$. Our density functional theory calculations predict a cosine-shaped bending of the dispersion…
Inelastic neutron scattering was used to study the Cu-O bond-stretching vibrations in optimally doped La1.85Sr0.15CuO4 (Tc = 35 K) and in two other cuprates showing static stripe order at low temperatures, i.e. La1.48Nd0.4Sr0.12CuO4 and…
The phonon dispersions of $\mathrm{Nd_{1.86}Ce_{0.14}CuO_{4+\delta}}$ along the $[\xi,0,0]$ direction have been determined by inelastic x-ray scattering. Compared to the undoped parent compound, the two highest longitudinal phonon branches,…
Inelastic x-ray scattering (IXS) was used to study the Cu-O bond-stretching vibrations in the static stripe phase compound La1.48Nd0.4Sr0.12CuO4. It was found that the intrinsic width in Q-space of the previously reported huge anomalous…
Interactions with electronic excitations can soften and/or broaden phonons. They are greatly amplified at wavevectors Q+- that connect parallel (nested) sheets of the Fermi surface. In such a case, called a Kohn anomaly, the phonon…
We report the first measurement of the optical phonon dispersion in optimally doped single layer Bi2Sr1.6La0.4Cu2O6+delta using inelastic x-ray scattering. We found a strong softening of the Cu-O bond stretching phonon at about q=(0.25,0,0)…
We report high-resolution inelastic x-ray scattering measurements of the acoustic phonons in the single-layer cuprate $Bi_{2}Sr_{2-x)La_{x}CuO_{6+\delta}$. These measurements reveal anomalous broadening of the longitudinal acoustic phonon…
The c-axis polarized phonon spectra of single crystals of YBCO_{6+x} have been measured for the doping range x=0.5 -> 0.95, between 10 K and 300 K. The low background electronic conductivity, determined by Kramers-Kronig analysis of the…
We observe strong softening of optical phonon modes in superconducting (Tc = 4.2 K) boron doped diamond near the Brillouin zone center using inelastic x-ray scattering from a CVD-grown highly oriented sample. The magnitude of the softening,…
The lattice dynamics of Ba1-xKxFe2As2 (x = 0.00, 0.27) have been studied by inelastic X-ray scattering measurement at room temperature. K doping induces the softening and broadening of phonon modes in the energy range E = 10-15 meV.…
Despite the intensive efforts for determining the mechanism that causes high-temperature superconductivity in copper oxide materials, no consensus on the pairing mechanism has been reached. Recent advances in high resolution angle-resolved…
The dispersion of phonons in Ba1-xKxBiO3 along the (3+q, 0, 0) direction in reciprocal space was determined for x=0, 0.30, 0.37, 0.52 using high-resolution inelastic X-ray scattering. The observed phonon energies near \Gamma were in good…
Inelastic neutron scattering is used to measure the temperature dependent phonon dispersion in Ca$_{2-x}$Sr$_{x}$RuO$_{4}$ ($x=0.4$, 0.6). The in-plane $\Sigma_{4}$ octahedral tilt mode softens significantly at the zone boundary of the high…
We present measurements of $ab$-plane resistivity $\rho_{ab}(T)$ and superfluid density [$\propto \lambda^{-2}$, $\lambda$ = magnetic penetration depth] in $La_{2-x}Sr_{x}CuO_{4}$ films. As Sr concentration $x$ exceeds about 0.22, the…
Utilizing resonant inelastic x-ray scattering, we report a previously unobserved mode in the excitation spectrum of La$_{2-x}$Sr$_x$CuO$_4$ at 500 meV. The mode is peaked around the ($\pi$,0) point in reciprocal space and is observed to…