Related papers: Electronic Raman Scattering in Superconducting Cup…
The superconducting phase of the 2D one-band Hubbard model is studied within the FLEX approximation and by using an Eliashberg theory. We investigate the doping dependence of $T_c$, of the gap function $\Delta ({\bf k},\omega)$ and of the…
A theory of electronic Raman scattering in the presence of several energy bands crossing the Fermi surface is developed. The contributions to the light scattering cross section are calculated for each band and it is shown that the cross…
New electronic Raman and I.R. spectroscopy results from optimally and overdoped high temperature superconducting (HTSC) cuprate systems are interpreted in terms of the negative-U, boson-fermion crossover model. Distinction is made between…
Recent inelastic neutron scattering (INS) experiments on La$_{2-x}$Sr$_x$CuO$_4$ observed a {\it magnetic coherence effect}, i.e., strong frequency and momentum dependent changes of the spin susceptibility, $\chi''$, in the superconducting…
Microscopy (STM). At all dopings, the low energy density-of-states modulations are analyzed according to a simple model of quasiparticle interference and found to be consistent with Fermi-arc superconductivity. The superconducting…
Here we use pristine graphene samples in order to analyze how the Raman peaks intensity, measured at 2.4 eV and 1.96 eV excitation energy, changes with the amount of doping. The use of pristine graphene allows investigating the intensity…
The doping dependence of spin excitations in Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ is studied based on a two-orbital model under RPA approximation. The interplay between the spin-density-wave (SDW) and superconductivity (SC) is considered in…
We have performed polarized Raman scattering measurements on the newly discovered superconductor Ba$_{2}$Ti$_{2}$Fe$_{2}$As$_{4}$O$_{2}$ ($T_c = 21$ K). We observe seven out of eight Raman active modes, with frequencies in good accordance…
Inelastic neutron scattering for Nd$_{2-x}$Ce$_x$CuO$_{4+\delta}$ near optimal doping ($x \approx 0.155$, $T_{c} = 25 \mathrm{K}$) reveals that the dynamic magnetic susceptibility at the antiferromagnetic zone center exhibits two…
We analyze the doping dependence of the intensity and energetical position of shadow states in high -T$_{c}$ superconductors within the 2D Hubbard model and using our recently developed numerical method for the self consistent summation of…
The dynamical spin response of doped two-leg ladder antiferromagnets is investigated based on the fermion-spin approach. Our calculations clearly demonstrate a crossover from the incommensurate antiferromagnetism in the weak interchain…
Superconductivity-induced changes in the electronic Raman scattering response were observed for the RNi$_2$B$_2$C (R = Y, Lu) system in different scattering geometries. In the superconducting state, 2$\Delta$-like peaks were observed in…
We show by non resonant effect in HgBa$_2$CuO$_{4+\delta}$ (Hg-1201)and by Zn substitutions in YBa$_2$Cu$_3$O$_{7-\delta}$ (Y-123) compounds that the fully symmetric Raman spectrum has two distinct electronic contributions. The A$_{1g}$…
We show that electronic Raman scattering affords a window into the essential properties of the pairing potential $V_{\mathbf{k},\mathbf{k^{\prime}}}$ of iron-based superconductors. In Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ we observe band…
The superconducting, transport, and structural properties of optimally electron-doped BaFe$_{1.9}$Ni$_{0.1}$As$_{2}$ are investigated by combining the electrical resistance and synchrotron X-ray diffraction measurements at high pressures.…
We report an ultrafast Time-Resolved Raman scattering study of the out-of-equilibrium photoinduced dynamics across the superconducting to normal state phase transition of the cuprate Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. Using the…
We report on the ab-plane reflectance of the high temperature superconductor Bi2Sr2CaCu2O8+d (Bi-2212). Samples spanning the doping range from under doped with Tc = 67 K(UD), to optimally doped with Tc = 96 K (OPT), to over doped with Tc =…
Polarized and unpolarized triple-axis spectrometry has been used to study an underdoped YBa_2Cu3O6.6. Our results indicate that spin excitations in the superconducting state are essentially the same as those in the fully doped material…
Within the kinetic energy driven superconducting mechanism, the magnetic nature of cuprate superconductors is discussed. It is shown that the superconducting state is controlled by both charge carrier gap function and quasiparticle coherent…
There are two commonly discussed points of view in theoretical description of cuprate superconductors, (i) Cuprates can be described by the modified t-J model. (ii) Overdoped cuprates are close to the regime of normal Fermi liquid (NFL). We…