Related papers: Is doped BaBiO$_3$ a conventional superconductor?
The soft ferro-electric phonon in SrTiO3 observed with optical spectroscopy has an extraordinary strong spectral weight which is much stronger than expected in the limit of a perfectly ionic compound. The "charged phonon" in SrTiO3 is…
BaBiO3 is a material where formally Bi4+ ions with the half-filled 6s-states form the alternating set of Bi3+ and Bi5+ ions resulting in a charge ordered insulator. The charge ordering is accompanied by the breathing distortion of the BiO6…
Results from different sets of band calculations for undoped and doped HgBa$_2$CuO$_4$ show that small changes in localization can lead to very different ground states. The normal LDA results are compared with 'modified' LDA results, in…
While both the hole and electron doped cuprates can exhibit $d_{x^2-y^2}$-wave superconductivity, the local distribution of the doped carriers is known to be significantly different with the doped holes going primarily on the O sites while…
Phonon dynamics, charge response and the phonon density of states are calculated for the high-temperature superconductors HgBa$_{2}$CuO$_{4}$ and Bi$_{2}$Sr$_{2}$CuO$_{6}$ within a microscopic model for the electronic density response. The…
Phonon frequencies at Gamma-point in non-magnetic rhombohedral phase of LaCoO3 were calculated using density functional theory (DFT) with hybrid exchange correlation functional PBE0. The calculations involved a comparison of results for two…
The recent proposal of antidoping scheme breaks new ground in conceiving conversely functional materials and devices, yet the few available examples belong to the correlated electron systems. Here we demonstrate both theoretically and…
We investigate the Fano-type line shape of the Ba mode of Y_{1-x}Ca_xBa_2Cu_3O_{6+y} films observed in Raman spectra with A_1g symmetry. The line shape is described with an extended Fano formula that allows us to obtain the bare phonon…
Doped SrTiO$_3$, one of the most dilute bulk systems to display superconductivity, is perhaps the first example of an unconventional superconductor, as it does not fit into the standard BCS paradigm. More than five decades of research has…
Using density functional theory (DFT), this work explores barium zirconate doped with nitrogen. In addition, we used density functional theory (DFT) to study the BaZrO$_3$'s electrical, optical, and structural properties, and we found that…
In the case of Li-intercalated hexagonal boron nitride bilayer (Li-hBN), the vertex corrections of electron-phonon interaction cannot be omitted. This is evidenced by the very high value of the ratio $\lambda\omega_{D}/\varepsilon_{F}\sim…
We calculate the effect of local magnetic moments on the electron-phonon coupling in BaFe$_{2}$As$_{2}+\delta$ using the density functional perturbation theory. We show that the magnetism enhances the total electron-phonon coupling by $\sim…
The isotropic, non-magnetic doped BaBiO$_3$ superconductors maintain some similarities to high-Tc cuprates, while also providing a cleaner system for isolating charge density wave (CDW) physics that commonly competes with superconductivity.…
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 recent discovery of 2D superconductivity at the interface of BaPbO$_3$ (BPO) and BaBiO$_3$ (BBO) has motivated us to study in depth the electronic and structural properties and the relation between them in this particular…
Bismuth perovskites ABiO$_3$ (A = Sr, Ba) host a variety of peculiar phenomena including bond-disproportionated insulating phases and high-temperature superconductivity upon hole doping. While the mechanisms underlying these phenomena are…
Pb doping effect in the Bi$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10}$ compound (Bi2223) on the structural and electronic properties were investigated, using the Local Density (LDA) and Virtual Crystal (VCA) approximations within the framework of the…
We present density functional theory calculations of phosphorus dopants in bulk silicon and of several properties relating to their use as spin qubits for quantum computation. Rather than a mixed pseudopotential or a Heitler-London…
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…
Topological insulators are a new class of insulators with conducting surface state. Most of the topological insulators are chalcogenides, where a tiny amount of chalcogen vacancy destroys the predicted bulk insulating state and results in a…