Related papers: Is doped BaBiO$_3$ a conventional superconductor?
We propose a new route to achieve the superconducting state in Boron-rich solids, the hole doping of B$_{12}$ icosahedra. For this purpose we consider a prototype metallic phase of B$_{13}$C$_2$. We show that in this compound the Boron…
The wide band gap semiconductor \b{eta}-Ga2O3 shows promise for applications in high-power and high-temperature electronics. The phonons of \b{eta}-Ga2O3 play a crucial role in determining its important material characteristics for these…
Typical density-functional theory calculations that wrongly predict undoped cuprates to be metallic also predict Cu-O half- and full-breathing phonon energies that are significantly softer than observed, presumably because of weak on-site…
We explain the anomalous doping dependence of zone boundary $(\pi,0)$ and $(\pi,\pi)$ bond-stretching phonons in the high-temperature superconductor La$_{2-\delta}$Sr$_{\delta}$CuO$_4$ in the doping range $0<\delta<0.35$. Our calculations…
The material BaBiO$_{3}$ is known for its insulating character. However, for thin films, in the ultra-thin limit, metallicity is expected because BaBiO$_{3}$ is suggested to return to its undistorted cubic phase where the oxygen octahedra…
We present a polarization resolved study of the low energy band structure in the optimally doped iron pnictide superconductor Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ (T$_c$=37K) using angle resolved photoemission spectroscopy.…
W\"olfle and Balatsky Phys. Rev. B 98, 104505 (2018) have proposed a microscopic pairing mechanism for doped SrTiO$_3$ (STO) based on the ${\textit gradient}$ coupling of electronic density to the soft TO phonon mode. Since this coupling to…
BaBiO3 is a prototype ``charge ordering system'' forming interpenetrating sublattices with nominal valence Bi(3+) and Bi(5+). It can also be regarded as a three-dimensional version of a Peierls insulator, the insulating gap being a…
The structural and electronic properties of La$_{2-x}$Ba$_x$CuO$_4$ were investigated as a function of Ba-concentration $0 \leq x \leq 1.2$, within the virtual crystal approximation (VCA) by means of first-principles total-energy…
The study of phonon coupling in doped semiconductors via electrical transport measurements is challenging due to unwanted temperature-induced effects such as dopant ionisation and parallel conduction. Here, we study phonon scattering in 2D…
We have performed x-ray absorption spectroscopy (XAS) and x-ray photoemission spectroscopy (XPS) studies of single crystal Ba_{1-x}K_{x}BiO_{3} (BKBO) covering the whole composition range $0 \leq x \leq 0.60$. Several features in the oxygen…
Much progress has been made recently in the study of the effects of electron-phonon (el-ph) coupling in doped insulators using angle resolved photoemission (ARPES), yielding evidence for the dominant role of el-ph interactions in underdoped…
The LDA-1/2 method is employed in density functional theory calculations for the electronic structure of III-V dilute bismide systems. For the representative example of Ga(SbBi) with Bi concentrations below $10 \%$, it is shown that this…
Using ultrafast optical techniques, we detect two types of bosons strongly coupled to electrons in the family of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ from the underdoped to overdoped regimes. The different doping dependences of the…
Motivated by the recently renewed interest in the superconducting bismuth perovskites, we investigate the electronic structure of the parent compounds ABiO$_{3}$ (A= Sr, Ba) using $ab$ $initio$ methods and tight-binding (TB) modeling. We…
Electron-doped strontium titanate $\rm{SrTiO_3}$, known to be one of the most dilute superconductors, is investigated on the basis of the first-principles calculations. When the carrier density n decreases, the frequencies of the…
Motivated by the observation of superconductivity in SrTiO$_3$ and Bi, we analyze phonon-mediated superconductivity in three-dimensional systems at low carrier density, when the chemical potential $\mu$ (equal to Fermi energy at $T=0$) is…
We consider superconductivity in boron (B) doped diamond using a simplified model for the valence band of diamond. We treat the effects of substitutional disorder of B ions by the coherent potential approximation (CPA) and those 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,…
Recent experiments on Nb-doped SrTiO$_3$ have shown that the superconducting energy gap to the transition temperature ratio maintains the Bardeen-Cooper-Schrieffer (BCS) value throughout its superconducting dome. Motivated by these and…