Related papers: Evidence for weak electronic correlations in Fe-pn…
The role of Coulomb correlations in the iron pnictide LaFeAsO is studied by generalizing exact diagonalization dynamical mean field theory to five orbitals. For rotationally invariant Hund's rule coupling a continuous transition from a…
Ge$_{1-x}$Fe$_{x}$ (Ge:Fe) shows ferromagnetic behavior up to a relatively high temperature of 210 K, and hence is a promising material for spintronic applications compatible with Si technology. We have studied its electronic structure by…
Multiorbital models are important to both the correlation physics and topological behavior of quantum materials. LiFeAs is a prototype iron pnictide suitable for indepth investigation of this issue. Its electronic structure is strikingly…
We present an X-ray spectral analysis of 21 low redshift quasars observed with XMM-Newton EPIC. All the sources are Palomar Green quasars with redshifts between 0.05 and 0.4 and have low Galactic absorption along the line-of-sight. A large…
The electronic structure of the heavy fermion compound CeB6 is probed by resonant inelastic soft X-ray scattering using photon energies across the Ce 3d and 4d absorption edges. The hybridization between the localized 4f orbitals and the…
Quantum oscillation measurements can provide important information about the Fermi surface (FS) properties of strongly correlated metals. Here, we report a Shubnikov-de Haas (SdH) effect study on the pnictide parent compounds…
The optical spectrum of the cubic helimagnetic metal FeGe has been investigated in the frequency range from 0.01 - 3.1 eV for different temperatures from 30 K to 296 K. The optical conductivity shows the evolution of a low energy (0.22 eV)…
One important yet exceedingly rare property of the cuprate high-temperature superconductors is the presence of a single correlated $d$ band in the low-energy spectrum, leading to the one-band Hubbard model as the minimal description. In…
High-temperature superconductivity in Fe-based pnictides and chalcogenides has been one of the most significant recent discoveries in condensed matter physics and has attracted remarkable attention in the last decade. These materials are…
We present a detailed first principles study of Fe-pnictides with particular emphasis on competing magnetic interactions, structural phase transition, giant magneto-elastic coupling and its effect on phonons. The exchange interactions…
Here we show that the low temperature phase of magnetite is associated with an effective, although fractional, ordering of the charge. Evidence and a quantitative evaluation of the atomic charges are achieved by using resonant x-ray…
This paper presents the energy dependence of multiplicity and net-electric charge fluctuations in p+p interactions at beam momenta 20, 31, 40, 80, and 158 GeV/c. Results are corrected for the experimental biases and quantified with the use…
The new rare-earth arsenate superconductors are layered, low carrier density compounds with many similarities to the high-Tc cuprates. An important question is whether they also exhibit weak-coupling across randomly oriented…
Explaining the mechanism of superconductivity in the high-$T_c$ cuprates requires an understanding of what causes electrons to form Cooper pairs. Pairing can be mediated by phonons, the screened Coulomb force, spin or charge fluctuations,…
(Abridged)The X-ray measurements of the ICM metallicity are becoming more frequent due to the availability of powerful X-ray telescope with excellent spatial and spectral resolutions. The information which can be extracted from the…
Accurate elastic scattering angular distribution data measured at bombarding energies just above the Coulomb barrier have shapes that can markedly differ from or be the same as the expected classical Fresnel scattering pattern depending on…
Motivated by recent experiments, we append long ranged Coulomb interactions to dominant strong local correlations and study the resulting $t$-$J$-$V_C$ model for the 2-dimensional cuprate materials. This model includes the effect of short…
The magnetic susceptibility of the two-dimensional repulsive Hubbard model with nearest-neighbor hopping is investigated using the diagram technique developed for the case of strong correlations. In this technique a power series in the…
The coupling between lattice and charge degrees of freedom in condensed matter materials is ubiquitous and can often result in interesting properties and ordered phases, including conventional superconductivity, charge density wave order,…
The electronic structures of multiferroic oxides of Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3) (0 < x < 0.12) have been investigated by employing photoemission spectroscopy and soft x-ray absorption spectroscopy (XAS). The measured Fe and Ti 2p XAS…